FoundMyFitness · 2025-09-09 · Rhonda Patrick (host), Derek
How To Increase Your Testosterone Levels Naturally | Derek from MPMD
101 research-tied claims examined: 4 contradicted 5 overstated 5 context 76 supported 11 unverified
4 Contradicted by research
Saturated fat intake increases endogenous cholesterol production.
"a certain amount of saturated fat, which is known to increase endogenous cholesterol production." (said at 1:00:58)
Dietary saturated fat does not increase endogenous cholesterol synthesis. Human kinetic and isotope tracer studies show that saturated fat intake results in equivalent or lower fractional and absolute cholesterol synthesis rates compared to polyunsaturated fat intake. Saturated fats elevate circulating low-density lipoprotein (LDL) cholesterol primarily by downregulating hepatic LDL receptor activity and reducing LDL particle clearance from circulation, rather than by stimulating endogenous cholesterol production.
- contradicts: Interaction of dietary fat saturation and cholesterol level on cholesterol synthesis measu… (Journal of lipid research 1994) · cited 36x in the literature
"FSR was increased (P < 0.02) by feeding corn oil, versus beef fat, but not by dietary cholesterol level. Calculated cholesterol pools sizes did not differ across groups; however, ASR was also elevated with corn oil versus beef tallow feeding (P < 0.02)." (abstract, results, passage verified)
pubmed - contradicts: Diet fat saturation and feeding state modulate rates of cholesterol synthesis in normolipi… (The Journal of nutrition 1997) · cited 29x in the literature
"FSR during 12-h periods were greater (P = 0.045) when subjects ate the POLY diet rather than the SAT diet. Absolute synthesis was also greater (P = 0.04) when subjects were fed, but did not differ with fat type (P = 0.789). Results suggest that cholesterol synthesis is greater when men are fed than when they are not fed, and reduced synthesis is not responsible for the effect of different fats on cholesterol concentrations." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Regulation of cholesterol biosynthesis by diet in humans. (The American journal of clinical nutrition 1997) · cited 78x in the literature
"In contrast, consumption of oils rich in polyunsaturated fatty acids, despite reducing circulating concentrations, increases the cholesterol synthesis rate compared with other fats." (abstract, results, passage verified)
pubmedfull study (doi)
Tongkat Ali suppresses SHBG and upregulates steroidogenic acute regulatory protein (StAR) to transport cholesterol into mitochondria for testosterone production.
"The main mechanism that people seem to agree on that it does do suppression of SHBG to some extent as well as the upregulation of steroidogenesis intratesticularly, so like locally upregulating I believe it's steroidogenic acute regulatory protein that basically incorporates cholesterol into the mitochondria to actually undergo these enzymatic cleaving sequences that result in the production of testosterone locally." (said at 1:15:36)
The claim asserts that Tongkat Ali (Eurycoma longifolia) suppresses SHBG and upregulates steroidogenic acute regulatory protein (StAR) in Leydig cells to stimulate testosterone production. Randomized controlled trials evaluating Tongkat Ali in healthy young men and aging men found no significant changes in SHBG levels compared to placebo. Furthermore, mechanistic research on Eurycoma longifolia's active quassinoid, eurycomanone, indicates that intratesticular testosterone increases occur primarily via inhibition of aromatase (decreasing the conversion of testosterone to estradiol) and phosphodiesterase, rather than an established primary upregulation of StAR.
- partial: Eurycomanone, the major quassinoid in Eurycoma longifolia root extract increases spermatog… (Journal of ethnopharmacology 2013) · cited 96x in the literature
"Eurycomanone enhanced testosterone steroidogenesis at the Leydig cells by inhibiting aromatase conversion of testosterone to oestrogen, and at a high concentration may also involve phosphodiesterase inhibition." (abstract, conclusions, passage verified)
pubmedfull study (doi) - contradicts: The effect of Eurycoma Longifolia on the regulation of reproductive hormones in young male… (Andrologia 2021) · cited 12x in the literature
"Blood analysis using repeated measures analysis of variance showed significant interaction and time effects for testosterone (F 1,30 = 9.04, p = .005), free testosterone (F 1,30 = 7.13, p = .012) and estradiol (F 1,30 = 8.07, p = .008) levels in favour of the treatment group, while luteinising hormone, follicle-stimulating hormone and sexual hormone-binding globulin did not." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Effect of Eurycoma longifolia standardised aqueous root extract-Physta ® on testosterone l… (Food & nutrition research 2021) · cited 19x in the literature
"There were no significant changes in SHBG." (abstract, results, passage verified)
pubmedfull study (doi)
Supplements like tribulus, D-aspartic acid, and fenugreek have been disproven as effective testosterone boosters.
"I think a lot of those have been disproven, like tribulus, D-aspartic acid, fenugreek." (said at 1:20:10)
The speaker bundles three supplements into the claim that they have been disproven as testosterone boosters. While the evidence against Tribulus terrestris and D-aspartic acid supports the speaker's statement, the assertion regarding fenugreek is contradicted by published systematic reviews and meta-analyses:
1. Tribulus terrestris: Systematic reviews demonstrate that clinical trials in humans fail to show an increase in testosterone levels (e.g., PMID 24559105, PMID 37697053).
2. D-aspartic acid: Systematic reviews of human randomized trials show inconsistent or absent effects on testosterone concentrations in healthy men (PMID 28280794, PMID 37697053).
3. Fenugreek: In contrast to the claim, systematic reviews and meta-analyses of randomized clinical trials have found that standardized fenugreek seed extract produces statistically significant increases in total and free testosterone concentrations in men (PMID 32048383, PMID 33150931).
Because the least accurate component of the bundled claim (fenugreek) is directly contradicted by meta-analytic evidence showing efficacy, the overall claim is graded contradicted.
- supports: A systematic review on the herbal extract Tribulus terrestris and the roots of its putativ… (Journal of dietary supplements 2014) · cited 86x in the literature
"Evidence to date suggests that TT is ineffective for increasing testosterone levels in humans, thus marketing claims are unsubstantiated." (abstract, results, passage verified)
pubmedfull study (doi) - supports: The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review. (International journal of reproductive biomedicine 2017) · cited 34x in the literature
"Our results showed that exogenous D-Asp enhances testosterone levels in male animal's studies, whereas studies in human yielded inconsistent results." (abstract, results, passage verified)
pubmed - contradicts: Effect of fenugreek extract supplement on testosterone levels in male: A meta-analysis of … (Phytotherapy research : PTR 2020) · cited 27x in the literature
"Fenugreek extract has a significant effect on total serum testosterone. Results from clinical trials suggest that fenugreek extract supplement has an effect on serum total testosterone levels in male." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Examining the Effects of Herbs on Testosterone Concentrations in Men: A Systematic Review. (Advances in nutrition (Bethesda, Md.) 2021) · cited 57x in the literature
"The main findings of this review indicate that 2 herbal extracts, fenugreek seed extracts and ashwagandha root and root/leaf extracts, have positive effects on testosterone concentrations in men." (abstract, results, passage verified)
pubmedfull study (doi)
Finasteride inhibits two of the three 5-alpha reductase isoenzymes, resulting in approximately 60 to 70% inhibition of systemic DHT.
"versus only 60 to 70% via finasteride, which only inhibits two of the three isoenzymes in the scalp." (said at 2:49:00)
The speaker bundles two assertions: the extent of systemic DHT suppression and the selectivity of finasteride for 5-alpha reductase (5-AR) isoenzymes. While it is true and well-established that finasteride reduces serum DHT by approximately 70%, the claim that finasteride inhibits two of the isoenzymes is incorrect. Finasteride is a selective inhibitor of only the type 2 5-AR isoenzyme at clinical doses (having negligible affinity for type 1), whereas dutasteride is the dual inhibitor that targets both type 1 and type 2 isoenzymes.
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.