FoundMyFitness · 2026-02-10 · Rhonda Patrick (host), Charles Brenner

How To Boost NAD Levels To Fight Inflammation, Improve Recovery, and Slow Aging

61 research-tied claims examined: 2 contradicted 5 overstated 2 context 46 supported 6 unverified

Contradicted by research

1:01:02 Charles Brennercontradictedmoderate

NMN cannot enter cells directly because it has a phosphate group; orally ingested NMN must be converted back to NR before cellular entry.

"NR can get into cells. It can get decorated with the phosphates and converted into its final nucleotide form. NMN can't because NMN already has a phosphate. That phosphate has to be put on inside of cells. So if someone takes if someone is able to find a safe, pure form of NMN... that NMN is being converted back to NR before it gets into cells." (said at 1:01:02)

The speaker claimed that NMN cannot enter cells directly due to its phosphate group and must always be dephosphorylated to NR prior to cellular entry. While extracellular dephosphorylation of NMN to NR via ectoenzymes (such as CD73) represents a recognized metabolic pathway in many tissues, evidence demonstrates that intact NMN can be transported directly into cells. In 2019, research identified Slc12a8 as a specific, sodium-dependent NMN transporter (notably expressed in the small intestine and brain) that transports intact NMN rather than NR. Thus, the categorical assertion that NMN cannot enter cells directly is inaccurate.

contradicts: Slc12a8 is a nicotinamide mononucleotide transporter. (Nature metabolism 2019) · cited 283x in the literature
"Here we show that the Slc12a8 gene encodes a specific NMN transporter. We find that Slc12a8 is highly expressed and regulated by NAD+ in the murine small intestine. Slc12a8 knockdown abrogates the uptake of NMN in vitro and in vivo. We further show that Slc12a8 specifically transports NMN, but not nicotinamide riboside, and that NMN transport depends on the presence of sodium ion." (abstract, results)
pubmed full study (doi)

1:09:10 Charles Brennercontradictedmoderate

In a three-arm trial by McDermott et al., NR improved 6-minute walk test distance in peripheral artery disease patients, while placebo and NR plus resveratrol resulted in degraded walk performance.

"McDermott et al., and I believe that she's the top peripheral artery disease clinical trialist in the country. She's at Northwestern. Did a three-arm clinical trial: placebo versus nicotinamide riboside versus NR plus resveratrol, and found that the NR arm improved their six-minute walk test and the placebo arm as well as the NR plus resveratrol arm degraded their six-minute walk test." (said at 1:09:10)

The claim accurately identifies the three-arm randomized controlled trial in peripheral artery disease (PAD) by McDermott et al. (the NICE trial, PMID 38871717) and correctly states that nicotinamide riboside (NR) alone improved 6-minute walk distance (+7.0 m) while placebo declined (-10.6 m). However, the claim asserts that the NR plus resveratrol arm "degraded their six-minute walk test." In the published trial, NR plus resveratrol also improved 6-minute walk distance (by +26.9 meters relative to placebo among adherent participants), leading the authors to conclude that resveratrol did not add extra benefit to NR alone, rather than causing performance degradation.

contradicts: Nicotinamide riboside for peripheral artery disease: the NICE randomized clinical trial. (Nature communications 2024) · cited 33x in the literature
"At 6-month follow-up, compared to placebo, NR significantly improved 6-min walk (+7.0 vs. -10.6 meters, between group difference: +17.6 (90% CI: + 1.8,+∞). Among participants who took at least 75% of study pills, compared to placebo, NR improved 6-min walk by 31.0 meters and NR + resveratrol improved 6-min walk by 26.9 meters. In this work, NR meaningfully improved 6-min walk, and resveratrol did not add benefit to NR alone in PAD." (abstract, results, passage verified)
pubmed full study (doi)

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.