I love new longevity science. But in my practice, I recommend only what has shown real results in people, not just in mice.
NMN is one of the most popular "longevity" supplements in the United States right now, and I'm asked about it constantly: Does it work? Is it safe? Is it better than NR or NAD? Which one should I buy? Why do so many people stop taking it?
The short answer: NMN reliably raises NAD+ in the blood within about two weeks. But human trials haven't shown that this rise improves health outcomes. Pooled analyses found no benefit for muscle in older adults and no effect on weight, blood sugar or cholesterol, with only a small, early signal for blood pressure. In trials of up to 24 weeks, NMN was well tolerated, but long-term safety is unknown. For staying strong after 40, strength training with enough protein, plus creatine, has much stronger evidence.
Key takeaways
- NMN (nicotinamide mononucleotide) is a building block your body can turn into NAD+, a molecule every cell uses for energy and repair.
- NMN and NR raise blood NAD+ by a similar amount within 14 days.
- Pooled trials found no benefit for muscle in older adults and no effect on weight, blood sugar or cholesterol.
- There's a small, preliminary signal for lower blood pressure, mainly in people 60 and older.
- A large, year-long trial of NR in early Parkinson's disease found no benefit, and outcomes were slightly worse than placebo.
- In trials lasting up to 24 weeks, NMN was well tolerated. Long-term safety is unknown.
- The FDA confirmed in 2025 that NMN can be sold as a dietary supplement. Legal to sell doesn't mean proven to work.
- If you've taken NMN for months, felt nothing and the cost matters, the evidence gives no strong reason to continue.
What is NMN?
NMN stands for nicotinamide mononucleotide. It's a molecule your body makes naturally from vitamin B3, and it's one step away from NAD+ (nicotinamide adenine dinucleotide).
NAD+ is found in every cell. It helps turn the food you eat into energy, supports DNA repair and is used by enzymes called sirtuins that are involved in how cells respond to stress. You can't live without it.
Here's why NMN became so popular:
- NAD+ levels tend to fall with age in several tissues.
- Animal studies showed that boosting NAD+ improved many signs of aging in mice, from energy use to blood vessel function.
- NMN and NR became the most popular "NAD+ precursors," meaning compounds the body can convert into NAD+.
That logic sounds compelling, but there's a gap in it. A number that goes down with age doesn't prove that raising it helps. That's the question human trials need to answer: the number goes up, but does anything you care about improve?
NMN, NR, NAD+ and niacin: what's the difference?
| Name | What it is | How it's used |
|---|---|---|
| NAD+ | The active molecule your cells use | Sold as oral capsules, IV drips and injections |
| NMN | A precursor, one step from NAD+ | Oral supplement, the most searched |
| NR (nicotinamide riboside) | A precursor, two steps from NAD+ | Oral supplement, well studied in humans |
| Niacin (nicotinic acid) | A basic form of vitamin B3 | Cheap; can cause skin flushing at higher doses |
| Nicotinamide | Another form of vitamin B3 | Cheap; didn't raise blood NAD+ in a 2026 trial |
NMN vs NAD: which is better?
NAD+ itself is a large molecule, and much of it is broken down in the gut before it can be absorbed intact. That's one reason supplement makers turned to smaller precursors like NMN and NR. NAD+ IV drips have become popular in wellness clinics, but there are very few controlled trials showing health benefits from them, and they're expensive. Based on the current evidence, I wouldn't pay for them.
Is there NMN in food?
Yes, but only in tiny amounts. Foods like edamame, broccoli, avocado, cabbage and cucumber contain NMN at roughly a milligram or less per 100 grams. Supplements typically provide 250 to 1,000 milligrams, far more than any diet. Your body mainly makes NAD+ from vitamin B3 and the amino acid tryptophan, which a normal diet provides.
What do human trials of NMN show?
Almost every trial confirms that NAD+ goes up. Far fewer measure outcomes you'd actually care about, like strength, blood sugar or disease. And when those outcomes are pooled across trials, most don't move.
| Question | What the research found |
|---|---|
| Does NAD+ go up? | Yes. NMN and NR raised blood NAD+ by a similar amount within 14 days (Christen 2026). |
| Muscle in older adults? | No benefit for muscle mass, grip strength, walking speed or chair-stand time in pooled trials (Prokopidis 2025). |
| Weight, blood sugar, cholesterol? | No effect across 15 trials (Yang 2026). |
| Blood pressure? | A small drop, mainly in people 60+. The authors call it preliminary (Zhang 2026). |
| A large, long trial? | In 410 people with early Parkinson's, a year of NR showed no benefit and slightly worse outcomes than placebo (Brakedal 2026). |
Does NMN help muscle and strength?
Muscle loss with age is the most common reason people try NMN, so this matters. A 2025 meta-analysis pooled randomized trials in adults with an average age of 60 to 83. NMN didn't improve muscle mass, grip strength, walking speed or chair-stand time (Prokopidis 2025). Results for NR were mixed.
Individual trials show the same pattern. In 42 men aged 65 and older, 250 mg of NMN a day for 12 weeks raised NAD+ but didn't change muscle mass, with partial improvements in some walking and grip tests (Igarashi 2022). In 80 healthy middle-aged adults, 300 to 900 mg a day for 60 days improved walking distance in a 6-minute test (Yi 2023). These are real findings, but small and short, and the larger pooled analysis didn't confirm a broad benefit.
Does NMN help blood sugar or weight?
One small 2021 trial in 25 women with prediabetes found better insulin sensitivity in muscle after 10 weeks (Yoshino 2021). It was widely publicized, but a 2026 meta-analysis of 15 trials found no effect on fasting blood sugar or HbA1c (a three-month average of blood sugar), and no effect on weight or cholesterol (Yang 2026). An NR trial in men with obesity also found no change in insulin sensitivity (Dollerup 2018).
Does NMN lower blood pressure?
There's a small signal. A 2026 meta-analysis of 10 trials found that the bottom number (diastolic) dropped by about 2 mmHg overall, and the top number (systolic) dropped by about 4 mmHg only in people 60 and older (Zhang 2026). The authors describe this as preliminary and suggestive. It needs bigger, longer trials before anyone should rely on it.
Does NMN give you more energy?
NAD+ is involved in energy production, so it's a fair question. But trials haven't shown a reliable change in how energetic people feel. A rise in blood NAD+ isn't something you can feel, and the measurable outcomes in trials mostly stayed the same.
What does NMN do for your face and skin?
There are no good human trials showing that NMN improves wrinkles, skin elasticity or how old your face looks. "Before and after" photos online can't separate NMN from better sleep, skincare, lighting or other changes. For skin, daily sunscreen and a topical retinoid have far stronger evidence.
What did the 2026 NOPARK trial find?
NOPARK was one of the largest and longest tests of an NAD+ booster so far (Brakedal 2026). It enrolled 410 people with early Parkinson's disease at 11 hospitals in Norway. Half took NR 500 mg twice a day for a year; half took a placebo.
- Symptom scores got slightly worse on NR than on placebo, though the difference was smaller than what researchers consider clinically important. Non-motor symptoms also worsened more on NR.
- Serious side effects were less common on NR than on placebo.
How to read it: NOPARK tested NR, not NMN, in people with Parkinson's, not healthy adults. It doesn't show that NR or NMN harms healthy people. It does show that a large, well-run trial didn't find the benefit its researchers hoped for.
Is NMN better than NR?
Probably not by much. In a 2026 head-to-head trial, 65 healthy adults took 1 gram a day of NMN, NR, nicotinamide or placebo for 14 days. NMN and NR raised blood NAD+ by a similar amount. Nicotinamide didn't (Christen 2026).
The same research ran lab tests with human gut bacteria. They suggest that gut microbes convert much of the NMN and NR you swallow into niacin, a basic form of vitamin B3, which then raises NAD+. In other words, the expensive molecule may work partly through a cheap vitamin pathway. This was one study from researchers at Nestlé, a company with commercial interest in NAD+ products, and it needs confirmation. But it's a good reminder that expensive doesn't always mean different.
| NMN | NR | |
|---|---|---|
| Raises blood NAD+ | Yes | Yes, similar amount |
| Human safety data | Trials up to 24 weeks | More trials, some longer |
| Outcome benefits in pooled trials | Not shown | Not shown |
| Cost | Usually higher | Usually similar or lower |
How much NMN should you take?
There's no official recommended dose, because NMN isn't an essential nutrient. In human trials, doses ranged from 250 to 2,000 mg a day for up to 24 weeks (Yang 2026). Most commercial products provide 250 to 1,000 mg.
- Higher doses raise NAD+ more, but no trial shows that higher doses improve health outcomes more.
- "Sublingual" (under the tongue) and "liposomal" versions are marketed as better absorbed, but I haven't seen good comparative human data.
- Timing (morning vs evening) hasn't been tested in a meaningful way. Most people take it in the morning with breakfast.
How long does NMN take to work?
| Timeframe | What the research shows |
|---|---|
| About 14 days | Blood NAD+ rises (Christen 2026) |
| 6 to 52 weeks | Trials measuring health outcomes mostly found no change |
| Long term | Unknown |
If you decide to try NMN, set a clear end date and a way to judge it, such as a blood pressure log, so you're not taking it indefinitely on hope.
NMN with resveratrol: does it help?
NMN is often sold with resveratrol, a compound from grape skins, based on a theory that the two work together on sirtuins. That theory comes from lab and animal research. Resveratrol is poorly absorbed in humans, and I'm not aware of human trials showing that the combination improves health outcomes. I'd treat combination products as marketing rather than evidence.
Is NMN safe? Side effects and what we don't know
In trials lasting up to 24 weeks, at doses of 250 to 2,000 mg a day, NMN didn't increase side effects, serious side effects, dropouts or liver enzymes compared with placebo (Yang 2026). NR has also been well tolerated in trials (Martens 2018; Dollerup 2018).
Side effects people report outside trials include mild stomach upset or nausea, headache, flushing or feeling warm, and trouble sleeping if taken late in the day.
What we don't know
- Long-term safety beyond about six months.
- Safety in pregnancy or while breastfeeding.
- Safety in people with cancer. NAD+ is used by all cells, including cancer cells, and some researchers have raised a theoretical concern based on lab and animal studies. There's no human evidence that NMN causes cancer, but there's also no long-term data to rule out effects in people with existing cancer. If you have a current or past cancer diagnosis, talk to your oncologist first.
- Product quality. Independent testing of NMN content varies by brand, and some products may not contain what the label says.
What should you not mix with NMN?
There's no good data on NMN combined with specific medications. If you take any prescription medication, talk to your doctor or pharmacist before adding NMN or NR.
Is NMN like Ozempic?
No. GLP-1 medications such as Ozempic act on appetite and blood sugar hormones and produce large weight loss in trials. NMN and NAD+ supplements haven't shown any effect on weight in pooled trials (Yang 2026). Read more in my guide to Ozempic face.
Is NMN legal in the US?
Yes. Here's the short history:
| When | What happened |
|---|---|
| Late 2022 | The FDA said NMN was excluded from supplements because it had been studied as a drug. |
| 2023 | Trade groups filed a petition, and later a lawsuit, asking the FDA to reverse course. |
| September 2025 | The FDA confirmed that NMN can be sold as a dietary supplement. |
That settled a legal question, not a scientific one. Supplements don't need FDA approval before sale, and the FDA doesn't test whether they work.
Why do people stop taking NMN?
From public discussions, the most common reasons are:
- "I don't feel anything." That's expected. A rise in blood NAD+ isn't something you can feel.
- Cost. Many people pay for it every month, often for years.
- Stomach upset in some users, although in trials side effects were no more common than with placebo.
- Quality doubts. People wonder whether the capsule contains the amount on the label.
Some articles answer "why I stopped taking NMN" with "you shouldn't stop." My view is simpler: if you've taken NMN for months, felt nothing and the money matters to you, the trial data don't give you a strong reason to continue.
What happens when you stop?
There are no trials on stopping NMN. Blood NAD+ likely drifts back toward your starting level, since the rise depends on taking it. No study has reported withdrawal effects.
How to choose an NMN supplement (if you decide to try it)
I'm not going to recommend a brand, since Centenarius doesn't sell NMN and I haven't tested them. But here's what I'd look for:
- Third-party testing for content and purity, with a certificate of analysis you can actually read.
- A clear dose per capsule, not a "proprietary blend."
- Heavy metal and microbial testing.
- No exaggerated claims. Be wary of "reverses aging," "anti-aging breakthrough" or before-and-after photos.
- A realistic price. More expensive doesn't mean more effective.
What I'd choose instead
If your goal is to stay strong, capable and independent as you age, I'd put my energy and budget where the outcome data are:
| Option | What the human evidence shows |
|---|---|
| Strength training | The strongest tool for keeping muscle and strength with age |
| Enough protein | Extra protein boosts training gains, leveling off around 1.6 g per kg of body weight a day |
| Creatine | In older adults, creatine plus resistance training added more lean tissue and strength than training alone* |
| Good sleep | The foundation for recovery, appetite and mood |
| Daily movement | Walking and staying active support heart health and function |
None of these are exciting, but they've been tested on outcomes you can measure, not just on a number in your blood.
What's in the Centenarius Longevity Protocol
When I think about longevity supplements, I don't believe in one miracle pill. I believe in well-studied basics, properly combined and taken consistently for real, long-term results. That's why, in my practice, I recommend the Centenarius Longevity Protocol, and I personally take every product in it myself. Here's why.
The Centenarius Longevity Protocol brings together all seven Centenarius products: Grass-Fed Whey Protein Isolate, Creapure® Creatine, Marine Collagen, Japan-sourced Glycine, Dual Mag Power, Sleep & Mood Superior Formula and Smooth Moves. Two of them, whey protein and creatine, match the options with the strongest human data for muscle and strength after 40.* Centenarius Whey Protein, Creatine and Glycine are 3rd-party independently tested for heavy metals and purity.
It isn't an "anti-aging" product, and it doesn't claim to change how fast you age. It's a set of simple daily basics built around the evidence.
Before you start
If you take any medication, are pregnant or nursing, or have a health condition, talk to your healthcare provider before starting a supplement. Sleep & Mood contains 5-HTP. If you take an antidepressant or any other prescription medication, check with your healthcare provider before use.
When to see a doctor
Talk to a clinician before taking NMN or NR if you:
- take any prescription medication
- have a current or past cancer diagnosis
- are pregnant, trying to conceive or breastfeeding
- have liver or kidney disease
Questions I'm often asked
Does NMN actually work? It works at raising NAD+. It hasn't been shown to improve muscle, weight, blood sugar or cholesterol in pooled trials.
Has NMN been proven to slow aging? No. Human trials are small and short, and most measured NAD+ levels rather than health outcomes.
Is NMN better than NAD+? NAD+ is largely broken down in the gut, which is why precursors like NMN and NR are used. There's little controlled evidence for NAD+ capsules or IV drips.
NMN or NR? Neither has a clear edge. They raised NAD+ by a similar amount in a head-to-head trial.
How much NMN should I take daily? Trials used 250 to 2,000 mg a day. No trial shows that higher doses improve health outcomes more.
Is NMN safe? It was well tolerated in trials of up to 24 weeks. Long-term safety, and safety in pregnancy or with cancer, are unknown.
Is NMN banned by the FDA? No. The FDA confirmed in 2025 that it can be sold as a dietary supplement.
Is NMN good for women? No trial shows a benefit specific to women. The one positive blood sugar trial was in 25 women with prediabetes, and a later analysis of 15 trials found no overall effect.
Is NMN a waste of money? For most people, trials show little beyond a higher blood NAD+ level. Whether that's worth the cost is your choice, but the outcome data are thin.
What should I take instead of NMN? Strength training with enough protein, plus creatine, has outcome data for muscle and strength in older adults.
The bottom line
NMN is a fascinating idea that hasn't yet delivered in human trials. It raises a number in your blood, and so far that hasn't translated into measurable health benefits. If you're curious, it appears well tolerated in the short term, but go in with honest expectations, a clear end date and a quality-tested product. Healthy aging, as I see it, is built on less exciting but well-proven habits: moving your body, lifting something challenging, eating enough protein, sleeping well and choosing a few simple supplements with real evidence behind them.
References
- Christen S, et al. The differential impact of three different NAD+ boosters on circulatory NAD and microbial metabolism in humans. Nat Metab. 2026;8(1):62-73. doi:10.1038/s42255-025-01421-8 (Conducted at Nestlé Research.)
- Prokopidis K, et al. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. doi:10.1002/jcsm.13799
- Yang W, et al. Safety and metabolism-related outcomes of oral nicotinamide mononucleotide supplementation in adults: a systematic review and meta-analysis. Nutrients. 2026;18(14):2251. doi:10.3390/nu18142251
- Zhang M, et al. Effects of nicotinamide mononucleotide supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials. Nutrients. 2026;18(6):890. doi:10.3390/nu18060890
- Brakedal B, et al. Nicotinamide riboside for patients with early-stage Parkinson disease: the NOPARK randomized clinical trial. JAMA. 2026. doi:10.1001/jama.2026.18828
- Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021. PMID 33888596.
- Igarashi M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood NAD+ levels and alters muscle function in healthy older men. NPJ Aging. 2022. PMID 35927255.
- Yi L, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults. GeroScience. 2023. PMID 36482258.
- Dollerup OL, et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men. Am J Clin Nutr. 2018. PMID 29992272. 10. Martens CR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018. PMID 29599478. 11. Natural Products Association. Amid pressure from NPA, FDA declares NMN lawful in dietary supplements. September 2025.
