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FoundMyFitness · 2025-03-31 · Darren Candow

The Optimal Creatine Protocol for Strength, Brain, and Longevity | Darren Candow, PhD

77 research-tied claims examined: 2 contradicted 9 overstated 4 context 54 supported 8 unverified

54

Supported by research

0:00:17Darren Candowsupportedmoderate

A study examining 21 hours of sleep deprivation showed that creatine supplementation improved memory, cognition, and increased brain creatine content.

"And they measured it for 21 hours of sleep deprivation, and it really improved memory, cognition, and it increased brain creatine content." (said at 0:00:17)

A 2024 study investigated the effect of a high single dose of creatine monohydrate (0.35 g/kg) during 21 hours of sleep deprivation using magnetic resonance spectroscopy (1H-MRS and 31P-MRS) and cognitive testing. The trial found that creatine supplementation increased cerebral high-energy phosphate metabolism and the total creatine-to-N-acetylaspartate ratio (tCr/tNAA), while mitigating sleep-deprivation-induced declines in cognitive performance and processing speed.

0:02:30Darren Candowsupportedhigh

Creatine supplementation increases intramuscular phosphocreatine, which maintains ATP levels during muscle contractions and delays reliance on slower energy pathways.

"So it basically increases the ability to produce ATP or maintain it during an exercise session. So, for example, when you're doing, you know, a squat or leg press or even running, you're doing muscle contractions, and phosphocreatine, which is what we're going to be talking about today from creatine supplementation, it really maintains ATP, or adenosine triphosphate." (said at 0:02:30)

The speaker's statement accurately reflects established exercise physiology and metabolic biochemistry. Supplementation with creatine increases intramuscular total creatine and phosphocreatine (PCr) concentrations. During high-intensity muscle contractions, phosphocreatine donates a high-energy phosphate group to ADP via the creatine kinase reaction to rapidly resynthesize and maintain cellular ATP concentrations, thereby sustaining immediate anaerobic power output and buffering against fatigue.

0:02:40Darren Candowsupportedhigh

Creatine supplementation increases training volume, muscle strength, muscular endurance, power, and lean body mass.

"So it definitely seems to increase training volume, so that's either the load by the reps by the set or exercise capacity from a cardiovascular perspective. It definitely—if you were to choose one thing why creatine has been so effective, it's improving muscle strength. You could also encompass that with endurance and power. It also improves lean body mass." (said at 0:02:40)

The speaker's claim that creatine supplementation increases training volume, muscle strength, power/endurance, and lean body mass is well supported by extensive randomized controlled trials, systematic reviews, and meta-analyses. Scientific consensus, including the position stand of the International Society of Sports Nutrition (ISSN), confirms that creatine supplementation elevates intramuscular phosphocreatine stores, which enhances high-intensity exercise capacity and training adaptations (such as power, strength, and work volume) and promotes increases in lean body mass when paired with resistance training.

0:03:15Darren Candowsupportedhigh

Lean body mass measurements in clinical and laboratory settings capture blood, connective tissue, and soft tissue rather than directly measuring muscle mass, with skeletal muscle representing approximately 50% of lean body mass.

"when we measure lean body mass in the labs, we're technically measuring blood, connective tissue, soft tissue, so we're not directly measuring muscle mass. We need to do a lot more research on that. But in general, about 50% of the value of lean body mass we consider muscle." (said at 0:03:15)

In human body composition assessment (such as dual-energy X-ray absorptiometry, bioelectrical impedance analysis, and multi-compartment models), lean body mass (or fat-free mass) encompasses all non-adipose tissues, including bodily fluids/blood, visceral organs, and connective tissues, rather than isolating skeletal muscle alone. In standard anatomical and functional reference models, skeletal muscle constitutes approximately 40% to 50% of total lean body mass in healthy adults.

0:03:45Darren Candowsupportedlow

Creatine supplementation reduces inflammatory cytokines following long-duration endurance exercise such as marathons and triathlons.

"And the best lines of evidence from a recovery aspect come from long-duration aerobic exercise: a marathon, ultramarathon, a triathlon. It seems to reduce cytokines—so those are markers of inflammation." (said at 0:03:45)

Published clinical evidence supports the claim that short-term creatine supplementation reduces inflammatory markers and pro-inflammatory cytokines following long-duration endurance running. In experienced marathon runners completing a 30 km race, five days of creatine loading (20 g/day) significantly attenuated the post-race increase in the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) by 33.7% and prostaglandin E2 (PGE2) by 60.9% compared to control, while also reducing markers of cell damage such as creatine kinase and lactate dehydrogenase. Certainty is rated low due to limited sample sizes and reliance on specific, short-term loading protocols.

0:05:20Darren Candowsupportedhigh

Meta-analyses show that creatine supplementation combined with resistance training leads to greater increases in lean body mass, muscle size, and muscle performance compared to resistance training with a placebo.

"So when we look at all the meta-analyses, when you compare creatine and weight training to placebo and weight training, there is a greater increase in lean body mass, muscle size, as well as muscle performance." (said at 0:05:20)

Multiple systematic reviews and meta-analyses of randomized controlled trials demonstrate that combining creatine supplementation with resistance training produces significantly greater improvements in lean body mass, direct measures of muscle hypertrophy (size), and muscular strength/performance compared to resistance training with a placebo.

0:06:01Darren Candowsupportedmoderate

Mitochondria typically take 3 to 5 minutes to recover and resynthesize depleted intramuscular phosphocreatine stores after maximal exertion.

"So on average, if you were to totally wipe out your normal creatine stores, it takes about 3 to 5 minutes for your mitochondria to recover that. However, creatine really, really speeds up that recovery, which is great for the average person." (said at 0:06:01)

Physiological studies using 31P-magnetic resonance spectroscopy show that full resynthesis of depleted intramuscular phosphocreatine (PCr) stores after intense exercise occurs via mitochondrial oxidative phosphorylation, typically requiring several minutes (approx. 2 to 5 minutes depending on muscle pH and exercise intensity). Oral creatine supplementation increases resting intramuscular PCr availability and accelerates the rate of PCr resynthesis during recovery.

0:08:10Darren Candowsupportedhigh

Humans experience a progressive loss of type II muscle fibers starting after the fourth decade of life.

"And as we get older, after about the fourth decade, unfortunately, we start to lose these type II muscle fibers." (said at 0:08:10)

Human skeletal muscle research shows a progressive, age-related decline in muscle mass that selectively affects type II (fast-twitch) muscle fibers through both fiber atrophy (reduction in cross-sectional area) and fiber loss/denervation starting in midlife. Systematic reviews, whole-muscle autopsy studies, and muscle biopsy analyses confirm that while type I (slow-twitch) fibers remain relatively preserved in size, type II fibers exhibit preferential atrophy, deterioration, and progressive loss with advancing age.

0:13:25Darren Candowsupportedmoderate

Creatine supplementation reduces markers of whole-body protein breakdown, specifically leucine oxidation and urinary 3-methylhistidine, in young males but not in females.

"But from a muscle breakdown perspective, it seems to reduce something called leucine oxidation, primarily in young males, and that's an indicator of whole-body breakdown. We've also shown in our lab it reduces 3-methylhistidine, which is another indicator of whole-body breakdown, but nothing is directly shown in the muscle itself. And for some reason, females don't experience this." (said at 0:13:25)

A randomized controlled trial investigating acute creatine monohydrate supplementation in young healthy men and women found that creatine significantly decreased leucine oxidation (-19.6%) and plasma leucine rate of appearance (-7.5%) in males, but not in females. The study also demonstrated no direct increase in mixed-muscle protein fractional synthetic rate, indicating that creatine exerts anti-catabolic effects at the whole-body level in men without directly altering muscle protein synthesis rates.

0:16:35Darren Candowsupportedmoderate

A neuroimaging study from Brazil showed that vegans and omnivores have identical baseline brain creatine stores despite vegans having significantly lower skeletal muscle creatine content.

"So on average, vegans have substantially less muscle creatine compared to an omnivore or carnivore diet. But an elegant study out of Brazil about four years ago, they used sort of an MRI for the brain, and they showed that vegans and omnivores had the same amount of brain creatine stores." (said at 0:16:35)

Magnetic resonance spectroscopy (MRS) research conducted in Brazil (University of São Paulo) compared vegetarians/vegans and omnivores to evaluate the impact of dietary creatine intake on tissue stores. Solis et al. (2014) showed that despite virtually absent dietary creatine intake in vegetarians compared to omnivores, brain total creatine content in the posterior cingulate cortex did not differ significantly between groups (5.999 vs. 5.917 IU, p = 0.77). Subsequent work by the same group in 2017 confirmed that baseline tissue responses and synthesis differ between skeletal muscle and the brain, with the brain relying primarily on endogenous synthesis rather than dietary creatine.

0:18:00Darren Candowsupportedhigh

Approximately 95% of the body's creatine stores are housed within skeletal muscle.

"That's the whole 95%. We can't forget about the bone and brain are the main areas. Yep." (said at 0:18:00)

The claim is supported by established human physiology literature. Approximately 95% of the human body's total creatine pool is stored in skeletal muscle, with the remaining small fraction distributed across other tissues such as the brain, heart, testes, and other organs.

0:27:00Darren Candowsupportedhigh

The lowest daily creatine monohydrate dose shown to positively influence bone health outcomes is 8 grams per day, whereas trials administering 1 to 3 grams per day for two years showed no skeletal benefit.

"the lowest dose ever been shown to be effective is 8 grams of monohydrate a day... But the Brazilian group have looked at 1 to 3 grams for two straight years and not a single improvement." (said at 0:27:00)

Randomized controlled trials confirm both parts of the claim. A 2-year double-blind, randomized, placebo-controlled trial conducted in São Paulo, Brazil evaluated creatine monohydrate supplementation (at 1 g/day for 1 year and 3 g/day for 2 years) in postmenopausal women with osteopenia and found no significant improvement in areal bone mineral density, bone microarchitecture, bone turnover markers, or fracture rates. In contrast, trials demonstrating favorable effects on bone health outcomes (such as bone mineral density and bone geometry when combined with resistance training) have utilized higher dosages, typically 0.1 g/kg/day (approximately 8 grams per day) or higher.

0:19:54Darren Candowsupportedhigh

In 1992, Roger Harris established the creatine loading protocol of 20 grams per day for approximately 7 days to saturate skeletal muscle creatine stores.

"So I mean, in 1992, Roger Harris came up with a seminal protocol where you just mentioned this loading phase. It's the most viable, rapid way to really saturate your skeletal muscle. This has nothing to do with the bone or the brain. And so that's 20 grams a day for about 7 days is usually what's recommended." (said at 0:19:54)

Roger Harris and colleagues published a landmark 1992 clinical study demonstrating that oral creatine supplementation (specifically 5 g doses taken 4 to 6 times daily, or 20–30 g/day, for several days) significantly increased skeletal muscle total creatine and phosphocreatine content, approaching an upper saturation limit. This work established the standard loading protocol (typically 20 g/day for 5–7 days) widely used in sports nutrition.

0:21:10Darren Candowsupportedmoderate

A single dose of creatine under 1 gram does not increase blood creatine concentrations as rapidly or effectively as larger doses.

"I wouldn't go any less than 1 gram. One gram doesn't seem to get in the blood as rapidly as we need. So that's something for your viewers, if they're microdosing, no less than 1 gram." (said at 0:21:10)

Pharmacokinetic data show that single oral doses of 1 gram or less of creatine monohydrate result in only minor elevations in plasma creatine concentration, whereas standard doses of 5 grams produce substantial and rapid peaks (~800 μmol/L within 1 hour) required for substantial muscle creatine uptake.

0:35:45Darren Candowsupportedhigh

Creatine is synthesized endogenously by both the liver and the brain.

"our liver produces creatine, and our brain actually is unique: it also produces creatine." (said at 0:35:45)

Creatine is synthesized endogenously through a two-step pathway catalyzed by L-arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase (GAMT). While systemic synthesis is coordinated primarily by the kidneys (forming guanidinoacetate via AGAT) and the liver (which completes creatine synthesis via GAMT), the mammalian brain also expresses both AGAT and GAMT across neurons and glial cells, allowing it to synthesize creatine locally to meet its energy demands due to limited creatine transport across the blood-brain barrier.

0:36:14Darren Candowsupportedhigh

The brain consumes approximately 20% of the body's daily energy.

"our brain is small from stature, but it uses 20% of our daily energy." (said at 0:36:14)

The claim that the human brain consumes approximately 20% of the body's daily energy expenditure is well-supported by physiological and neurobiological literature. Although the adult human brain accounts for only roughly 2% of total body mass, it accounts for approximately 20% to 25% of resting metabolic energy expenditure.

0:37:56Darren Candowsupportedmoderate

Astrocytes in the central nervous system lack the creatine transporter, blunting circulating creatine uptake into the brain.

"astrocytes, which are the most the biggest in in our central nervous system... unfortunately, they don't have the creatine transporter or doorway, so that's why uptake into the brain is very blunted." (said at 0:37:56)

Under physiological conditions, the creatine transporter (SLC6A8) is expressed on microcapillary endothelial cells at the blood-brain barrier, but is absent from the surrounding astrocyte foot processes that line these capillaries. This absence of SLC6A8 in astrocyte feet restricts the movement of circulating creatine across the blood-brain barrier into the central nervous system, limiting peripheral creatine uptake into the brain.

0:38:28Darren Candowsupportedlow

In a study of individuals with long COVID, 4 grams per day of creatine took three months to accumulate in the brain as measured by MRS.

"There's been a single study looking at about 4 grams a day, but it took three months to accumulate in the brain... The study that did 4 grams was in long COVID; these individuals: brain fog, fatigue, headaches, things like that." (said at 0:38:28)

The speaker accurately describes a pilot randomized controlled trial evaluating 4 g/day of creatine supplementation over a 3-month intervention period in patients with long COVID. In this trial (n=8), magnetic resonance spectroscopy (MRS) was used to measure tissue creatine, demonstrating a significant increase in total creatine across all evaluated brain and muscle regions after 3 months of supplementation compared to the control group. Because the study sample size was very small (n=8), the certainty of evidence for the intervention's broader clinical efficacy is low.

0:42:22Darren Candowsupportedmoderate

A German crossover study administering 0.35 g/kg of creatine during 21 hours of sleep deprivation improved memory, cognition, and brain creatine content.

"another study came out of Germany: they did a very elegant design, it was a crossover, and they gave 0.35 grams per kilogram... and they measured it for 21 hours of sleep deprivation, and it really improved memory, cognition, and it increased brain creatine content." (said at 0:42:22)

A 2024 randomized, double-blind, placebo-controlled crossover study conducted in Germany (Gordji-Nejad et al., Forschungszentrum Jülich) evaluated the effects of a single high dose of creatine monohydrate (0.35 g/kg) in healthy adults subjected to 21 hours of sleep deprivation. Using magnetic resonance spectroscopy (1H-MRS and 31P-MRS) alongside neurocognitive batteries, the researchers found that creatine administration increased brain total creatine (tCr/tNAA) and high-energy phosphate availability (PCr/Pi, ATP), prevented intracellular pH drops, and improved cognitive performance and processing speed compared to placebo.

0:46:08Darren Candowsupportedlow

A Scottish study administering 0.4 g/kg of creatine per day to children following head trauma showed improvements in self-care and efficacy over six months.

"the only single human study was in children: as soon as these people in Scotland got head trauma, they put them on 0.4 grams of creatine per kilogram, so about 20—these are just children—immediately, and over six months, these children that were taking creatine had substantial improvements in self-care and efficacy." (said at 0:46:08)

An open-label randomized pilot study (Sakellaris et al., 2006) evaluated 39 children and adolescents aged 1 to 18 years with traumatic brain injury (TBI) who received 0.4 g/kg/day of oral creatine suspension for 6 months. Patients receiving creatine demonstrated significant improvements in self-care (p = 0.029), cognitive function (p < 0.001), communication, personality/behavior, and reduced ICU stay and post-traumatic amnesia compared to controls. The study took place in Greece (University of Crete), not Scotland, but the dosage, duration, population, and specific outcome measures match the speaker's description. The certainty is rated low due to the small sample size and open-label design.

0:48:40Darren Candowsupportedmoderate

A six-week study in resistance-training females found that creatine supplementation increased total sleep duration on training days by approximately one hour compared to placebo.

"colleagues at University of Ottawa and Brown and CJ Brush, and they looked at young healthy uh individuals, biological females, and we gave a pretty high dose here: 5 grams, plus we add a 5 grams of placebo... total sleep duration on the days they trained was substantially higher—I think it was about almost an hour compared to placebo." (said at 0:48:40)

A double-blind randomized controlled trial by Brush et al. (2024) evaluated 21 naturally menstruating females undergoing resistance training twice per week over six weeks. Participants received either 5 g creatine plus 5 g maltodextrin daily or a 10 g maltodextrin placebo. Sleep tracking with Ōura rings demonstrated that the creatine group experienced a statistically significant increase in total sleep duration specifically on resistance training days compared to the placebo group.

0:53:20Darren Candowsupportedhigh

A large five-year trial conducted in Germany failed to find clinical benefits of creatine supplementation in neurodegenerative disease.

"when you look at a properly sample-sized study, there was a big one, five years in Germany, didn't see any greater effects." (said at 0:53:20)

Randomized clinical trials evaluating long-term creatine supplementation (with durations extending up to 5 years) in neurodegenerative conditions such as Parkinson's disease, amyotrophic lateral sclerosis (ALS), and Huntington's disease have consistently failed to demonstrate clinical disease-modifying benefits or slowing of functional decline.

  • supports: Creatine for neuroprotection in neurodegenerative disease: end of story? (Amino acids 2016) · cited 97x in the literature
    "This has led to a number of randomized clinical trials (RCT) with oral Cr supplementation, with durations up to 5 years. In this paper, we review the evidence and consequences stemming from these trials. In the case of PD, the initial phase II RCT was promising and led to a large and well-designed phase III trial, which, however, turned out to be negative for all outcome measures. None of the RCTs that have examined effects of Cr in ALS patients showed any clinical benefit." (abstract, passage verified)
    pubmedfull study (doi)
0:59:50Darren Candowsupportedmoderate

Vascular endothelial cells express creatine transporters.

"the endothelial cells at the blood-brain barrier especially, but around all the um smooth muscle, they do have the transporter." (said at 0:59:50)

Published reviews and in vitro mechanistic studies confirm that vascular endothelial cells, particularly microcapillary endothelial cells forming the blood-brain barrier, express the solute carrier family 6 member 8 (SLC6A8) creatine transporter to mediate creatine uptake.

1:00:01Darren Candowsupportedmoderate

Studies by researchers including Eric Rawson and Mike Ormsbee showed creatine supplementation improved macro- and microvascular function in older adults.

"Mike Ormsbee just put out a study, and Eric Rawson just recently in older adults... and they show some very small favorable effects from creatine supplementation uh either a week long or for up to 4 weeks... it has some favorable effects for in I think it was macro- and microvascular function." (said at 1:00:01)

Recent randomized controlled trials co-authored by researchers including Michael J. Ormsbee and Eric S. Rawson investigated the short-term effects of creatine monohydrate supplementation on vascular health in older adults. A 2024 pilot double-blind randomized crossover trial by Ormsbee's group evaluated 4 weeks of creatine supplementation in sedentary older adults and found significant improvements in both macrovascular endothelial function (measured via flow-mediated dilation, increasing from 7.68% to 8.90%) and microvascular endothelial function (microvascular reperfusion rate increasing from 2.29%/s to 3.71%/s) relative to placebo. Additionally, a 2024 randomized trial evaluating 7 days of creatine supplementation in older men found improvements in vascular parameters, including the cardio-ankle vascular index.

0:44:51Darren Candowsupportedmoderate

Individuals with depression or concussions exhibit lower brain creatine levels and reduced bioenergetics compared to healthy controls.

"And if and one of the common denominators with depression or concussion is that they have reduced brain creatine stores and bioenergetics compared to a healthy control on average." (said at 0:44:51)

Published magnetic resonance spectroscopy (MRS) studies demonstrate that individuals with depression and traumatic brain injury/concussion exhibit reductions in brain creatine concentrations and altered bioenergetics compared to healthy controls in specific brain regions. A systematic review and meta-analysis in adolescent depression found significant reductions in creatine levels within the anterior cingulate cortex (SMD: -0.50, 95% CI: -0.96 to -0.03). Similarly, neuroimaging studies in mild traumatic brain injury and post-concussion syndrome report significant decreases in total creatine across multiple regions of interest relative to healthy controls, with lower creatine levels correlating with increased symptom severity.

0:52:51Darren Candowsupportedhigh

Creatine supplementation provides clinical benefits in young boys with muscular dystrophy.

"There's benefits on young boys with muscular dystrophy, but that's a little bit different." (said at 0:52:51)

Multiple randomized controlled trials and a Cochrane systematic review demonstrate that creatine supplementation provides clinical benefits, including increased muscle strength, fat-free mass, cellular energetics, and resistance to fatigue, in boys with muscular dystrophies (such as Duchenne muscular dystrophy). A 2013 Cochrane meta-analysis of randomized controlled trials concluded that high-quality evidence shows short- and medium-term creatine treatment significantly increases muscle strength and functional outcomes in individuals with muscular dystrophy.

0:54:21Darren Candowsupportedhigh

All published clinical studies evaluating creatine for depression have administered it as an adjunct to antidepressant therapy rather than as a monotherapy.

"as a caveat, no study has ever looked at creatine without antidepressant medication, so they're always as adjunct." (said at 0:54:21)

Systematic reviews of clinical trials examining creatine for major depressive disorder and bipolar depression confirm that all published trials have tested creatine as an adjunctive or augmentation strategy (primarily combined with selective serotonin reuptake inhibitors or other standard therapies), rather than as a standalone monotherapy. Review authors explicitly note the absence of clinical trials evaluating creatine monotherapy in the absence of first-line treatments.

0:58:50HOSTsupportedlow

Glutamine supplementation reduces the incidence of upper respiratory tract infections in endurance runners.

"There's like a few studies showing that these these um marathoners and stuff, they they don't get as much as many respiratory illnesses if they're taking glutamine. GUEST1: Yeah, no, I'm very familiar." (said at 0:58:50)

The host claimed that studies show marathoners taking glutamine experience fewer upper respiratory tract infections. This claim is supported by controlled clinical studies and reviews by Castell et al., which demonstrated that oral glutamine supplementation after prolonged, exhaustive exercise (such as a marathon or ultra-marathon) significantly reduced the self-reported incidence of subsequent infections/upper respiratory illness compared to placebo (PMID 9263279, PMID 9839078). However, broader systematic reviews note that evidence across nutritional interventions remains heterogeneous and limited in methodological quality, resulting in a overall low certainty of evidence (PMID 17136044).

1:01:37Darren Candowsupportedmoderate

Studies investigating the cardiometabolic effects of creatine show mixed findings, with some reporting decreases in triglycerides and LDL cholesterol while others show no effect.

"It's totally mixed. Um some show decrease in triglycerides, LDL, um um and then others don't see the effect." (said at 1:01:37)

The literature evaluating the cardiometabolic and lipid effects of creatine supplementation is indeed mixed. Individual randomized trials have occasionally reported favorable changes or reductions in triglycerides and cholesterol fractions (such as LDL cholesterol), while other trials have observed no significant alterations. A systematic review and meta-analysis of 8 randomized placebo-controlled trials found that across pooled studies, creatine supplementation produced no statistically significant or clinically meaningful overall effect on total cholesterol, LDL-C, HDL-C, or triglycerides, reflecting the inconsistent results seen across individual investigations.

1:02:07Darren Candowsupportedmoderate

Creatine supplementation combined with resistance training decreases body fat in individuals aged 18 and older by about 1% or about 0.5 kg compared to resistance training alone.

"Creatine decreases body fat in combination with resistance training compared to resistance training alone. Correct. Yeah, now small, about 1% or about 0.5 kg." (said at 1:02:07)

Meta-analyses of randomized controlled trials demonstrate that combining creatine supplementation with resistance training leads to a small reduction in body fat compared to resistance training alone. In adults under 50 years of age, meta-analytic data show a significant reduction in body fat percentage of approximately 1.19% (PMID: 37892421). In older adults (≥50 years of age), creatine with resistance training led to an additional 0.55% reduction in body fat percentage and approximately 0.5 kg greater fat mass loss compared to placebo plus resistance training (PMID: 33467377).

1:04:08Darren Candowsupportedmoderate

Creatine supplementation increases myogenic regulatory factors during rehabilitation from muscle disuse or injury.

"The studies that looked at from a rehabilitation perspective, creatine seemed to increase these things called myogenic transcription factors. So without boring your audience, these are little guys that sort of tell DNA to sort of increase proteins in a quicker way. So these myogenic regulatory factors went up during rehabilitation." (said at 1:04:08)

A double-blind randomized controlled trial (Hespel et al., 2001) evaluated the effect of oral creatine supplementation versus placebo during 2 weeks of cast immobilization followed by 10 weeks of rehabilitation in 22 healthy young volunteers. Quadriceps muscle biopsies demonstrated that during rehabilitation, creatine supplementation significantly increased protein expression of the myogenic transcription factor MRF4 compared with placebo, and this increase correlated with muscle fiber hypertrophy (r = 0.73).

1:04:30Darren Candowsupportedmoderate

In a cast-immobilization trial, creatine supplementation maintained muscle strength.

"and then we did a study when we got individuals to put on a cast, volunteer, and creatine seemed to maintain strength." (said at 1:04:30)

The speaker accurately describes a cast-immobilization study evaluating creatine supplementation. In a randomized crossover trial in young men with upper-limb plaster cast immobilization (PMID 19130643), creatine supplementation significantly attenuated the loss of muscle strength compared to placebo (elbow flexor strength declined by 4.1% with creatine vs. 21.5% with placebo; elbow extensor strength declined by 3.8% vs. 18.0%). Subsequent trials in lower-limb immobilization (e.g., PMID 28054322) have shown mixed results, but the specific finding from the upper-limb cast study matches the speaker's statement.

1:04:49Darren Candowsupportedmoderate

Creatine supplementation increases muscle satellite cells and IGF-1, decreases myostatin, and reduces reactive oxygen species.

"it does it has been shown to increase satellite cells, which are needed for um recovery and rehabilitation, growth factors, IGF-1, and decreases myostatin, the one that increases protein breakdown. ... And then again, on the other side, it's certainly been shown to decrease reactive oxygen species" (said at 1:04:49)

The speaker's claims accurately reflect published research on the mechanistic and physiological actions of creatine supplementation. Evidence shows that creatine supplementation (particularly in combination with resistance exercise) enhances muscle satellite cell proliferation and mitotic activity, increases muscular expression of insulin-like growth factor-1 (IGF-1), significantly decreases circulating and intramuscular myostatin levels, and exhibits antioxidant properties that reduce reactive oxygen species (ROS) and oxidative stress.

1:08:09Darren Candowsupportedmoderate

Two Canadian meta-analyses found that creatine combined with resistance training in older adults improved functional tasks like sit-to-stand performance.

"Two meta-analyses have been performed, both in Canada. We were fortunate to do one. Stu Phillips, I know, has been a guest, I think, for you and um uh we've done two meta-analyses. And then when you look at creatine in older adults with resistance training, though, it did improve tasks of functionality, sit-to-stand, so getting out out of the bed, off the toilet, getting out of a chair." (said at 1:08:09)

Canadian meta-analyses of randomized controlled trials have examined creatine supplementation combined with resistance training in older adults. Notably, a 2014 meta-analysis led by researchers at McMaster University (Devries & Phillips) evaluated randomized trials in older adults and found that creatine supplementation combined with resistance training significantly enhanced functional performance, specifically showing a greater improvement on the 30-second chair stand (sit-to-stand) test compared to resistance training alone (P = 0.03). Subsequent Canadian meta-analyses (e.g., Chilibeck et al., 2017) confirmed significant gains in lean mass and upper- and lower-body muscular strength.

1:09:13Darren Candowsupportedlow

Research by Sergej Ostojic shows creatine supplementation does not downregulate sperm production and instead improves sperm vitality and motility.

"And my good colleague out of Norway, Sergej Ostojic, who's one of the world's best creatine researchers, has looked at this in many forms and not showing any effect. If anything, it improves the vitality and motility of sperm." (said at 1:09:13)

Research authored by Sergej Ostojic supports the assertion that creatine does not impair spermatogenesis biomarkers and may support sperm quality. A population-based cross-sectional study of over 1,300 males found no negative association between dietary creatine intake and serum biomarkers of spermatogenesis (inhibin B and FSH). Furthermore, a pilot randomized controlled trial by Ostojic and colleagues evaluating 8 weeks of creatine supplementation (alone or combined with ubiquinol) in 15 men found no downregulation of semen parameters; instead, 60% of creatine-supplemented men (and all oligospermic men in the creatine arms) experienced improvements in sperm concentration compared to 20% in the control group. However, evidence directly evaluating human semen parameters following supplementation remains preliminary due to small sample sizes.

1:11:15Darren Candowsupportedmoderate

Multiple studies by researchers such as Kerksick and Rawson show no adverse effects of creatine supplementation in young children and adolescents.

"Chad Kerksick and and Rawson, the Mayo Clinic here in the United States, are the two most profound researchers in that area, and they've looked at study after study in children, uh young children, adolescents, and there's no adverse effects." (said at 1:11:15)

Comprehensive reviews and position papers authored by researchers in this area (including Chad Kerksick and Eric Rawson, as well as investigators affiliated with the Mayo Clinic Health System) have evaluated the literature on creatine supplementation across pediatric and adolescent populations. In both clinical populations (such as children with inborn errors of metabolism or neuromuscular disorders) and adolescent athletic cohorts, published trials consistently report an absence of significant adverse events or adverse effects from creatine supplementation. While evidence indicates a favorable safety profile, reviews also note that randomized data in healthy, non-clinical young pediatric populations remain more limited in scope compared to the extensive adult literature.

1:20:06Darren Candowsupportedmoderate

The bioavailability of creatine monohydrate is nearly 100%.

"creatine monohydrate's bioavailability is near 100%. There might be a little bit extracted from the gut. So how can you get more than 100%?" (said at 1:20:06)

Human clinical and pharmacokinetic literature indicates that the gastrointestinal absorption of orally ingested creatine monohydrate is nearly complete (close to 100%). However, preclinical rat studies have observed lower absolute oral bioavailability (16% to 53% depending on dose), suggesting potential species-specific differences in first-pass metabolism or intestinal transport.

1:21:45Darren Candowsupportedmoderate

Taking creatine with food or carbohydrates increases its absorption via insulin-mediated mechanisms.

"With food seems to increase the absorption because the insulin from carbohydrates and/or some of the the effects of fat." (said at 1:21:45)

Human clinical trials demonstrate that co-ingesting creatine with carbohydrates (or a combination of carbohydrate and protein) substantially stimulates insulin secretion, which in turn enhances skeletal muscle creatine uptake and increases whole-body creatine retention by approximately 25% to 60% compared to creatine alone. While intestinal bioavailability of creatine is already high on its own, insulin facilitates the transport and accumulation of creatine from circulation into skeletal muscle.

1:30:14Darren Candowsupportedhigh

Creatine supplementation increases intracellular water, extracellular water, and total body water rather than causing dehydration or muscle cramping.

"It superhydrates the muscle. ... creatine is trapping water into the cell. It also has been shown to increase extracellular water and total body water in some studies. Um, so from a cramping or dehydration perspective, it's actually opposite." (said at 1:30:14)

Creatine acts as an intracellular osmolyte, drawing water into muscle cells and expanding total body water (TBW) and intracellular water (ICW), with some studies also documenting proportional increases in extracellular water (ECW). Multiple clinical trials and athletic cohort studies have shown that creatine supplementation does not cause muscle cramps or dehydration; rather, the associated hyperhydration often reduces or has no adverse effect on cramping and heat illness incidence.

1:28:00Darren Candowsupportedmoderate

A training study conducted by Darren Candow's group found that concurrent caffeine and creatine supplementation interfered with creatine's training benefits.

"And we've done the only training study—it was underpowered, but they did interfere with each other, yeah." (said at 1:28:00)

A 6-week randomized controlled resistance training trial led by Darren Candow's research group (Pakulak et al., 2022) evaluated the separate and combined effects of creatine and caffeine supplementation in trained young adults (n = 28 across 4 groups). The study found a significant group × time interaction for knee extensor muscle thickness, where the creatine-only group showed an increase over time, but the combined creatine-plus-caffeine group (as well as caffeine and placebo groups) did not, suggesting potential interference between concurrent caffeine and creatine supplementation during training, though the authors noted the small sample size.

1:30:49Darren Candowsupportedmoderate

Research in NCAA athletes by Rick Kreider showed that creatine supplementation does not increase muscle cramping or dehydration rates.

"I think Rick Kreider's done some studies with that when he looked at NCAA uh players." (said at 1:30:49)

Research led by Rick Kreider and colleagues evaluated NCAA Division IA college football players across training and competition seasons to assess whether creatine supplementation affected injury, dehydration, or cramping rates. The studies found that athletes taking creatine did not experience higher rates of muscle cramping or heat illness/dehydration compared to non-users; in fact, creatine users had significantly lower or proportional incidences of cramping and dehydration-related issues.

1:31:33Darren Candowsupportedhigh

Creatine supplementation does not adversely affect renal, liver, or cardiovascular cells, even at dosages of 11 grams per day in postmenopausal females.

"creatine does not adversely affect renal, liver, or cardiovascular uh cells. Uh, and we've given 11 grams a day in postmenopausal females to a population where their organs are under a little bit more stress, and no adverse effects." (said at 1:31:33)

Randomized controlled trials and meta-analyses in postmenopausal women demonstrate that creatine supplementation (including daily doses relative to body weight equivalent to high absolute intakes, as well as high-dose loading phases of 20 g/day) does not impair renal or hepatic function and is not associated with cardiovascular or organ toxicities compared to placebo.

1:31:53Darren Candowsupportedhigh

Creatine in muscle is non-enzymatically metabolized into creatinine.

"when creatine enters your muscle, when it gets metabolized, it's non-enzymatically metabolized into something called creatinine." (said at 1:31:53)

The speaker accurately describes the metabolic fate of creatine. In skeletal and cardiac muscle, creatine (and phosphocreatine) spontaneously degrades via an irreversible, non-enzymatic cyclization reaction into creatinine, which then diffuses into the bloodstream and is excreted by the kidneys.

1:35:28Darren Candowsupportedmoderate

The rugby study that measured DHT with creatine supplementation found no increase in free testosterone.

"to this day they cite this single study um that even didn't look at free testosterone, there was no increase." (said at 1:35:28)

In the 2009 randomized, double-blind crossover study of college-aged rugby players by van der Merwe et al., the investigators measured total serum testosterone (T) and dihydrotestosterone (DHT), but did not measure free testosterone. The study found that serum total testosterone concentrations did not change significantly after 7 days of creatine loading or a subsequent 14 days of maintenance supplementation, while DHT levels and the DHT:T ratio increased significantly.

1:36:49Darren Candowsupportedhigh

No rodent studies have investigated or shown hair loss from creatine supplementation.

"No rodent studies, nothing. I think it's an area that people said no one cared about, and then all of a sudden everybody cared about it." (said at 1:36:49)

The claim is supported. Comprehensive reviews evaluating the safety and potential side effects of creatine supplementation confirm that no rodent studies have evaluated or demonstrated hair loss resulting from creatine supplementation. Speculation regarding hair loss originated from a single 2009 human study that observed changes in serum dihydrotestosterone (DHT) without assessing hair loss, and subsequent scientific evaluations and direct clinical trials have found no evidence that creatine induces alopecia.

1:37:01Darren Candowsupportedmoderate

Creatine supplementation does not increase blood pressure or cause hypertension.

"The big one we're getting a lot is does it increase hypertension or blood pressure, because if it increases water into the body, could that have any effects? And we're not seeing any adverse effects there." (said at 1:37:01)

Randomized controlled trials and comprehensive literature reviews evaluating creatine monohydrate supplementation consistently show that it does not increase resting blood pressure or induce hypertension. Although creatine can cause intracellular water retention and increase fat-free body mass, clinical evaluations across diverse demographics (young healthy adults, athletes, and older adults) report no adverse changes in systolic, diastolic, or mean arterial blood pressure.

1:37:11Darren Candowsupportedmoderate

There is no evidence that creatine supplementation disrupts sleep.

"the other one is we do not see any evidence it disrupts sleep, although we talked about the the study earlier, doesn't have any negative effects there." (said at 1:37:11)

Current scientific literature does not show that creatine supplementation disrupts sleep. A randomized, double-blind, placebo-controlled crossover trial evaluating high-dose creatine monohydrate loading (20 g/day for 7 days) found no adverse effects on objective sleep metrics, including sleep latency, sleep efficiency, and total sleep time, while subjective sleep quality improved. Furthermore, population-level observational data from NHANES indicate that higher dietary creatine intake is associated with a lower prevalence of sleep disturbances rather than disruption.

1:39:39Darren Candowsupportedhigh

The creatine molecule does not stimulate urination or act as a diuretic.

"the creatine molecule, whichever, does not increase um urinary output... the molecule doesn't cause an increase in urination, it's not a diuretic, or it doesn't increase uh urinary uh flow that way." (said at 1:39:39)

The statement that creatine does not stimulate urination, increase urinary output, or act as a diuretic is supported by scientific evidence. Creatine is an osmotically active compound taken up primarily by skeletal muscle, where it draws water into the intracellular compartment rather than promoting fluid excretion. Systematic reviews and clinical trials examining body fluid balance and hydration status consistently demonstrate that creatine supplementation does not induce diuresis or dehydration, but instead promotes fluid retention (primarily intracellular) and maintains plasma volume.

1:41:58Darren Candowsupportedmoderate

Methionine methylation accounts for approximately 40% of the body's methyl group consumption for creatine synthesis.

"methionine is donating I think it's 40% of our methyl groups to creatine synthesis." (said at 1:41:58)

Endogenous synthesis of creatine via guanidinoacetate methyltransferase (GAMT) requires S-adenosylmethionine (derived from methionine) as the methyl donor. Biochemical reviews estimate that creatine synthesis accounts for approximately 40% of all labile methyl groups transferred from S-adenosylmethionine, placing a major metabolic demand on methionine and one-carbon metabolism.

1:41:31Darren Candowsupportedmoderate

The majority of studies evaluating creatine supplementation show it does not decrease homocysteine levels.

"Yeah, most studies don't support it, and that's where we got to the point where, oh, if it doesn't decrease homocysteine levels, then maybe exogenous creatine doesn't reduce our natural creatine synthesis... the majority suggests it doesn't decrease." (said at 1:41:31)

Randomized controlled trials evaluating creatine supplementation in humans generally show that it does not significantly decrease plasma total homocysteine concentrations in healthy populations, despite downregulating endogenous guanidinoacetate synthesis. While selective reductions have been observed in specific subgroups (such as hyperhomocysteinemic individuals or vegans), the overall body of human evidence indicates no significant lowering of homocysteine in the majority of trials.

1:43:40Darren Candowsupportedmoderate

More than 75 grams of carbohydrates is required to augment creatine uptake into muscle.

"the dose of carbohydrates shown to sort of increase it is almost over 75 grams, and I think most people are not going to consume that." (said at 1:43:40)

Randomized human physiological studies examining the insulin-mediated enhancement of creatine transport demonstrate that large amounts of carbohydrate (approximately 80 to 100 g simple sugars per dose) are required to significantly augment creatine retention and skeletal muscle accumulation. Testing showed that doses around 50 g of carbohydrate alone were insufficient to stimulate insulin release to the threshold needed to enhance creatine retention significantly compared to low carbohydrate intake, whereas ~93 to 96 g of carbohydrate (or ~47 g carbohydrate combined with ~50 g protein) reliably enhanced retention and muscle creatine uptake.

1:45:06Darren Candowsupportedmoderate

A 1992 study showed that exercising one leg increased muscle creatine uptake by about 37%, while the non-exercised leg still increased uptake by 25%.

"So the study in 1992 was very elegant: they had one leg exercise, and that increased creatine uptake by about 37%, and in the other leg that didn't exercise, it still improved by 25%." (said at 1:45:06)

The statement accurately reflects the findings of the landmark 1992 trial by Harris et al. (PMID 1327657). In the study, healthy subjects consumed 5 g of creatine monohydrate multiple times daily while performing 1 hour of single-leg cycle ergometer exercise per day. Creatine supplementation increased muscle total creatine content in both resting and exercised limbs, with exercise enhancing uptake by approximately 37% (about 37 mmol/kg dry muscle) compared to an approximately 25% increase (about 25 mmol/kg dry muscle) in the contralateral resting leg.

1:46:37Darren Candowsupportedhigh

Creatine monohydrate has Generally Recognized As Safe (GRAS) status.

"Monohydrate has GRAS status. Creapure is from Germany, it's more scrutinized, it has less impurities." (said at 1:46:37)

Creatine monohydrate has obtained Generally Recognized as Safe (GRAS) status in the United States for use in designated food products (e.g., FDA GRAS notices for creatine monohydrate including Creapure). Regulatory reviews and comprehensive safety evaluations confirm that creatine monohydrate is extensively studied, possesses an established safety profile across clinical trials, and is recognized globally as safe for use as a dietary supplement and food ingredient.

1:35:52Darren Candowsupportedmoderate

The study finding an increase in dihydrotestosterone (DHT) levels following creatine supplementation in rugby players has not been replicated.

"HOST: I mean, has first of all, has anyone replicated this study? It sounds like no. GUEST1: No." (said at 1:35:52)

The original 2009 randomized crossover trial by van der Merwe et al. in 20 college-aged male rugby players reported that creatine supplementation (25 g/day loading for 7 days followed by 5 g/day maintenance for 14 days) was associated with a 56% increase in serum dihydrotestosterone (DHT) after 7 days and remained 40% above baseline after maintenance. Subsequent comprehensive reviews and controlled studies examining androgen responses to creatine supplementation have noted that this isolated finding of increased DHT levels has not been replicated in the scientific literature.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.