Huberman Takes NMN. Attia Thinks It’s a Waste. Who’s Right?

Mike HartnettEvidence-Based

7+ years researching longevity protocols. Runs a 20+ supplement daily stack. Built CoreStacks after losing his father to heart disease.

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NMN is the most divisive supplement in longevity right now. Andrew Huberman takes it. David Sinclair built his career on it. Peter Attia won’t touch it. I take 500mg daily and spend $50-80/month on it. After following this debate for years, I land on Huberman’s side — but Attia’s skepticism is completely valid, and I’d be lying if I said the evidence was airtight.

This isn’t a simple “one expert is right and one is wrong” situation. It’s a genuine scientific disagreement about how much evidence you need before taking action. Your answer depends on your budget, your risk tolerance, and how you weigh mechanistic research versus clinical trials.

Huberman’s Case for NMN

Huberman has discussed taking NMN on multiple episodes of the Huberman Lab podcast, with dosages in the 500mg to 1g range. His reasoning follows a straightforward biological chain: NAD+ is essential for hundreds of cellular processes, NAD+ levels decline measurably with age, NMN is a direct precursor to NAD+, and supplementing NMN raises NAD+ levels in humans.

The mechanistic argument is genuinely compelling. NAD+ isn’t some obscure molecule — it’s involved in DNA repair, mitochondrial function, and the sirtuin pathways that regulate aging. The decline is well-documented. By age 50, your NAD+ levels may be half what they were at 20. That’s not disputed by anyone in the field.

Huberman has cited studies showing the enzymatic pathway from NMN to NAD+ via the enzyme NMNAT. Unlike some supplements where the absorption pathway is questionable, we have decent evidence that oral NMN actually reaches tissues and converts to NAD+. Blood NAD+ levels go up. That part isn’t controversial.

Sinclair has been the loudest NMN advocate for over a decade, taking 1g every morning. His research at Harvard on sirtuins and NAD+ metabolism forms the scientific backbone of the NMN argument. Between his published papers and Huberman’s platform, they’ve probably driven more NMN sales than any advertising campaign could.

For a deeper look at everything Huberman takes and why, I’ve broken down his full supplement stack here.

Attia’s Case Against NMN

Attia has been publicly skeptical of NMN on The Drive podcast and in interviews. His arguments are methodical, and honestly, hard to dismiss.

Argument 1: Blood levels aren’t outcomes. Yes, NMN raises NAD+ in blood. So what? Raising a biomarker isn’t the same as improving health. We need evidence that higher NAD+ actually translates to better clinical outcomes — less disease, better function, longer life. That evidence barely exists in humans.

Argument 2: The human trial data is thin. Most NMN research is in mice. Mouse studies are promising, but mice are not humans. The few human trials are small, short-term, and primarily measure NAD+ levels rather than meaningful health endpoints. Attia wants randomized controlled trials showing real outcomes before he’ll spend money on it.

Argument 3: The cost isn’t justified. At $50-80/month for quality NMN, you could spend that on things with much stronger evidence — like high-quality omega-3 fish oil or a gym membership. Attia’s broader philosophy prioritizes exercise, sleep, and nutrition over supplementation. When he does supplement, he wants strong data backing it.

Argument 4: He takes other things instead. Attia has discussed using rapamycin for longevity, which has much stronger data in animal models (the ITP studies are remarkable) and a growing body of human clinical experience. His approach to his own longevity protocol reflects this evidence hierarchy: exercise first, then pharmaceuticals with strong data, then supplements — and only the ones with real proof.

What the Research Actually Shows

I’ll be straight with you: the evidence for NMN in humans is early-stage. Not nonexistent, but not strong either.

Animal studies: Genuinely promising. NMN supplementation in mice has shown improvements in insulin sensitivity, endurance, cardiovascular function, and neurological health. Some mouse studies suggest lifespan extension, though not all. The animal data is why researchers got excited in the first place.

Human trials: A handful of small studies exist. The METRO trial showed NMN increased blood NAD+ levels and improved some walking performance metrics in older adults. Other small trials have shown increases in NAD+ metabolites. But we’re talking about studies with 30-50 participants over 60-90 days. No long-term safety data. No mortality data. No large-scale replication.

The gap: Between “NAD+ levels go up in blood” and “you’ll live longer or healthier,” there’s a canyon of unanswered questions. Does the NAD+ reach the tissues where it matters? Does it activate the sirtuin pathways meaningfully in humans? Are there long-term risks we haven’t seen yet in short trials? We don’t know.

For a more detailed breakdown of the NMN evidence, including how it compares to NR (nicotinamide riboside), see my NMN vs NR comparison and the question of whether NMN actually works.

My Verdict: I Take NMN (Here’s Why)

I take 500mg of NMN daily and have for over a year. I acknowledge every point Attia makes. The human evidence IS weak. Blood NAD+ levels going up IS a surrogate marker, not a clinical outcome. I could be making expensive urine.

But here’s my reasoning:

The mechanistic story is unusually strong. Most supplement mechanisms are hand-wavy. NMN’s pathway to NAD+ is well-characterized biochemistry. NAD+ decline with age is measured and documented. The connection to DNA repair, mitochondrial function, and sirtuin activation has decades of research behind it. This isn’t some random herb with vague “antioxidant properties.”

Two of the most visible longevity researchers take it themselves. Huberman and Sinclair have access to data, researchers, and personal biomarker tracking that I don’t. They’ve both decided the risk-reward ratio makes sense for them personally. That’s not proof, but it’s a meaningful signal.

The known risk profile is low. NMN has been studied in multiple human trials with no serious adverse effects reported. It’s a naturally occurring molecule in your body. The downside scenario is that it does nothing and I’ve spent $50-80/month on something useless. The upside scenario is meaningful cellular protection as I age.

At $50-80/month, it’s a bet I can afford. I’ve already covered the consensus supplements that every expert agrees on. NMN is my speculative allocation, similar to how some investors keep a small percentage in high-risk, high-potential-reward assets.

I lost my father to heart disease. That gives me a personal urgency that pure cost-benefit analysis doesn’t capture. I’d rather take a supplement that might help and learn later it didn’t than skip it and learn later it would have. That’s my bias. I own it.

If strong negative data emerged — evidence of harm, not just evidence of no benefit — I’d stop immediately. My stack has gotten smaller over time, not bigger. I dropped resveratrol and zinc when I couldn’t see or measure any benefit. NMN stays because the theoretical case is strong enough and the risk is low enough.

Who Should Take NMN (And Who Shouldn’t)

Skip NMN if:

• You haven’t covered the basics yet. Omega-3, vitamin D3+K2, magnesium, and creatine should come first. The evidence for all four is dramatically stronger than NMN.
• Your budget is under $50/month. Spend it on the consensus stack instead. Those four supplements run about $40-50/month and have real clinical data.
• You need certainty before spending money. NMN is a bet, not a proven intervention. If that bothers you, Attia’s approach is the rational one for you.

Consider NMN if:

• You’ve already built a solid foundation with consensus supplements and have room in your budget.
• You’re comfortable with speculative supplementation based on mechanistic evidence.
• You track your biomarkers and can potentially measure the impact. I’d recommend getting baseline bloodwork before starting.
• You’re over 40, when NAD+ decline becomes more pronounced.

I’d also recommend checking how NMN fits into the real costs of a longevity stack. Budget matters, and NMN shouldn’t crowd out things that work better. If you’re trying to keep costs down, I’ve worked out how to build a Huberman-inspired stack for under $100.

For a look at where NMN sits in the broader landscape of expert disagreements, I cover four other contested supplements in my breakdown of supplements experts can’t agree on.

If you want to try NMN, go with a reputable brand that does third-party testing. The ProHealth Longevity 500mg NMN is what I use, and I’ve compared options in my best NMN supplements ranking.

This content is for informational purposes only. Consult your healthcare provider before starting any supplement protocol.