NMN vs TRT for energy and testosterone: what the research says

What did @paulschriner actually say?

The short version: NMN supplements can replace TRT by restarting your "cellular factories," NAD decline after 30 is to blame for low testosterone, and the FDA is about to kill your access to cheap NMN. He claims his biohacking group saw "73% more energy in 30 days" and frames TRT as an industry scam while selling a $50/month sublingual supplement.

He's not subtle about the sales pitch. "Tap the cart and give them what they need" closes a video that opens with a genuine biochemistry question and ends as a product advertisement. That framing matters when we evaluate the science.

Does the science back this up?

Partially, and that's being generous. The Leydig cell-NAD connection is real biology. The leap from that biology to "NMN replaces TRT" is not supported by clinical evidence in humans.

Leydig cells in the testes do express NAD-dependent enzymes, including sirtuins, and animal research has shown that NAD precursor supplementation can influence steroidogenesis. A 2020 study by Yoshino et al. in Cell Metabolism found that NMN supplementation improved insulin sensitivity in postmenopausal women but did not measure testosterone. A 2023 randomized controlled trial by Yi et al. in GeroScience found modest NAD+ increases in older adults taking NMN, with no significant testosterone data reported. The gap between "NAD supports Leydig cell function in mice" and "NMN raises your testosterone like TRT" is enormous, and no peer-reviewed human trial has closed it.

The "NAD crashes harder than crypto after 30" line is directionally accurate. NAD+ levels do decline with age, as documented by Verdin in Science (2015). Whether that decline is the primary driver of age-related testosterone decline is unproven.

What did they get wrong (or right)?

Let's give credit where it's due. The basic science premise, that NAD+ is involved in Leydig cell function and declines with age, is not invented. That's real. The claim that TRT causes testicular atrophy is also accurate. Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis, reducing LH signaling to the testes, which shrinks them. That's textbook endocrinology.

Here's what's wrong. The "73% more energy" figure comes from his biohacking group, not a controlled study. That is anecdote laundered as data. Self-reported energy in a group of people already biased toward believing in a supplement they're taking together is about as reliable as a Yelp review written by the owner's cousin.

The claim that NMN "works better than TRT" for energy is unverifiable and almost certainly false for men with clinically confirmed hypogonadism. TRT has decades of controlled trial data. NMN has promising preclinical work and early-phase human trials. Presenting them as interchangeable alternatives is misleading in a way that could actually harm people who need treatment.

The FDA warning is also distorted. The FDA has flagged NMN because a pharmaceutical company filed an Investigational New Drug application, which legally complicates its sale as a supplement. That's a regulatory technicality, not a pharmaceutical conspiracy.

What should you actually know?

If you have symptoms of low testosterone, including fatigue, low libido, or mood changes, get a blood test. A single TikTok video about Leydig cells is not a diagnostic tool. NMN may support cellular energy metabolism, and the research is genuinely interesting, but it has not been shown in human trials to raise testosterone to therapeutic levels in men with hypogonadism.

TRT is not a scam. It is an FDA-approved treatment with real efficacy data for men who are actually deficient. Its downsides, including testicular atrophy and the need for monitoring, are real too, which is why it requires clinical oversight. NMN is not a replacement for that process.

If you want to explore NAD precursor supplementation, that's a reasonable conversation to have with a clinician. But making that decision based on a sales video that closes with "tap the cart" is a bad way to manage your health. The supplement industry is not your friend just because it's cheaper than a clinic.

Should you be worried about this video?

Yes, moderately. The danger here isn't outright fiction. It's a half-true framework used to sell a product and discourage people from seeking legitimate evaluation. Men with actual hypogonadism who watch this and decide to buy sublingual NMN instead of getting labs done may delay diagnosis of treatable conditions. That's a real harm, even if the biochemistry in the first 20 seconds is technically defensible.