Why People Stop Taking NMN (And Whether You Should)

Key Takeaways

People quit NMN mostly because of expectations, not evidence. NMN raises NAD+ quietly rather than producing a felt "buzz," so "I don't feel it" is not a sign it has stopped working (Christen et al., 2026). The 2022 fear that NMN was "banned" is outdated: the FDA reversed course in late 2025 and NMN is back on the market. The honest caveats are real too: human benefits beyond raising NAD+ are still modest, and the cost only makes sense at a sensible dose.

Why do people stop taking NMN?

Usually for one of six reasons, and most of them are fixable misunderstandings rather than real problems. The big ones are not feeling an effect, the running cost, the old "it got banned" headlines, doubt about long-term human evidence, hearing that NR is better, and expecting to feel younger within a month.

Here is the honest list of why people quit, in rough order of how often it comes up:

• "It doesn't feel like anything." NMN is not a stimulant. It raises NAD+ in the background, so there is usually no buzz to notice.
• "It got expensive." Taken daily at the wrong dose, NMN adds up fast, and people quit on value rather than results.
• "I heard it was banned." NMN vanished from many shelves in 2022, which scared a lot of people off. That has since been reversed.
• "I'm not convinced it does much long-term." Most of the dramatic claims come from mouse studies; human data is younger and more modest.
• "Someone said NR is better." The NMN-versus-NR debate pushes some people to switch.
• "I expected to feel 10 years younger." When that does not happen in a few weeks, people give up before the timeline the research actually suggests.

The rest of this guide takes each one in turn.

Is NMN still banned by the FDA?

No. NMN is lawful as a dietary supplement and back on the market. In 2022 the FDA took the position that NMN could not be sold as a supplement, on a technicality, and it disappeared from Amazon and many retailers. In late 2025 the FDA reversed that position.

The short history: NMN had once been studied as an investigational drug, and the FDA used a "drug preclusion" rule to exclude it from the supplement definition in 2022. Industry groups challenged that through petitions and a lawsuit, and on September 29, 2025 the FDA reversed course, confirming NMN was marketed as a supplement years earlier and is therefore not excluded. Follow-up letters to manufacturers in December 2025 formally reinstated its status (NutraIngredients, 2025).

So if you stopped taking NMN in 2022 or 2023 because it got pulled or you heard it was "illegal," that reason is gone. There is still a broader industry debate about how the FDA applies the preclusion rule in general, but NMN itself is settled and widely available again.

I don't feel anything on NMN, is it working?

Probably, yes. NMN is not a stimulant and was never meant to feel like one. It raises NAD+, a coenzyme your cells use for energy and repair, and that change happens quietly. Not feeling a noticeable lift is normal and does not mean it has failed.

This is the single biggest reason people quit, and it comes from expecting the wrong thing. In the 2026 Nature Metabolism head-to-head trial, NMN doubled circulating NAD+ within 14 days (Christen et al., 2026) — a real biological change you would never sense from the outside. The benefits researchers have actually measured, like better walking distance or insulin sensitivity in older adults, are functional and gradual, not a same-day energy hit.

If you want something to track instead of a "feeling," watch the slow stuff over weeks: workout recovery, endurance on the same route, afternoon energy. Those are the kinds of endpoints trials use, and they move quietly.

How long should you give NMN before deciding?

Give it 8 to 12 weeks. NAD+ rises within about two weeks, but the functional benefits measured in trials show up over 4 to 12 weeks. Quitting at two or three weeks because nothing dramatic happened is quitting before the evidence says to judge.

One practical detail explains a lot of disappointment: blood NAD+ peaks a few hours after a dose and drifts back toward baseline within about a day, which is exactly why daily dosing matters. Skipping days keeps your NAD+ on a rollercoaster instead of a steady lift. Most trials that found benefits ran consistent daily dosing for 8 to 12 weeks, so that is a fair window to evaluate before deciding. For timing tips, see our guide to the best time to take NMN.

Is NMN worth the cost?

It can be, if you take a sensible dose. The evidence-aligned range is 250 to 500 mg each morning, which is where cost and benefit line up best. Above roughly 900 mg, blood NAD+ gains flatten out, so you are mostly paying for NAD+ your body cannot use.

A lot of people quit on price because they were taking far more than the data supports. Dose-response trials show NAD+ rising with dose up to a point and then leveling off (Yi et al., 2023), so megadosing is usually wasted money rather than extra benefit. At a reasonable dose NMN runs roughly $50 to $100 a month. If that is uncomfortable, it is fair to put better-established, cheaper basics first and treat NMN as optional. Our NMN dosage guide breaks the numbers down.

Should you switch from NMN to NR?

You do not have to. The first head-to-head human trial put NMN and NR against each other and both doubled NAD+, with no significant difference between them. Switching out of fear that you picked the "wrong" one is not supported by the data.

NMN vs NR: the two main NAD+ precursors compared

Factor	NMN	NR (nicotinamide riboside)
Raises NAD+	Yes, shown in human trials	Yes, shown in human trials
US supplement status	FDA position is contested; availability shifts	Sold freely as a supplement
Human evidence base	Growing; mostly biomarker and small RCTs	Slightly longer track record
Felt effects	Often subtle or none short-term	Often subtle or none short-term
Typical dose	250–500 mg/day	300 mg/day

For years people argued NMN should beat NR because it sits one step closer to NAD+ in the pathway. When researchers finally tested them directly in the same study, both raised NAD+ equally, and both even nudged up beneficial gut short-chain fatty acids (Christen et al., 2026). The sensible way to choose between them is dose, price, and how you personally respond, not biochemistry theory. We lay out the full comparison in NMN vs NR.

Is NMN overhyped? What it does and doesn't do

Partly, and being honest about that actually helps you stick with it. NMN's NAD+-raising effect is rock solid across 12+ human trials. Its functional benefits are real but modest and mostly from single studies. The "reverses aging" claims are not proven in humans at all.

A lot of people quit out of disillusionment after the marketing oversold it. Here is the honest tiering: raising blood NAD+ is the most replicated finding. Functional benefits like aerobic capacity and muscle insulin sensitivity show up in individual well-designed trials but need more replication (Yoshino et al., 2021). And a 2024 meta-analysis of 12 studies found that while NAD+ reliably rose, most metabolic outcomes were not significantly different from placebo, with the authors warning that "an exaggeration of the benefits" may exist in the field (Zhang et al., 2025). If you go in expecting a steady, research-backed NAD+ support rather than a fountain of youth, you are far less likely to feel let down and quit.

Is NMN safe to keep taking?

By the available evidence, yes. Human trials at doses up to 1,250 mg/day for up to 12 weeks have reported no serious adverse events. Safety is rarely the real reason people stop; it is more often expectations or cost.

Across the published trials NMN has been well tolerated, and a 2023 safety review reached the same conclusion (Song et al., 2023). The honest gap is duration: most studies ran 12 weeks or less, so very long-term human data is still thin. That is a reason to choose a tested product and a sensible dose, not necessarily a reason to stop. Our roundup of what trials report on tolerability is in NMN side effects.

Who might reasonably pause NMN?

Some people genuinely should hold off, and that is different from quitting out of frustration. The clearest cases are pregnancy or nursing, being under 18, or being young and healthy with no real NAD+ decline yet.

If you are pregnant or breastfeeding, there is no human safety data, so it is not worth the risk. If you are under 18, your NAD+ is likely already at its peak and supplementing adds little. If you are under 40, active, and sleeping and eating well, your NAD+ may not be meaningfully depleted yet, so the upside is smaller. And if you take prescription medication for a chronic condition, check with your doctor first. NMN's clearest benefits have shown up in adults over 45 with measurable age-related decline.

How to take NMN so you actually stick with it

Take 250 to 500 mg each morning, every day, with food, and commit to an 8 to 12 week trial before you judge it. Set the right expectation up front: you are supporting NAD+, not chasing a daily buzz.

The people who stay on NMN tend to do three things: they dose consistently each morning so NAD+ stays elevated, they pick a sensible dose so the cost stays reasonable, and they track slow functional markers rather than waiting to "feel" something. Set a simple reminder, give it a couple of months, and decide based on how you function, not on day-three impressions. That alone prevents most of the quitting this article is about.

What Specific NMN Benefits Does Clinical Evidence Support?

The confirmed benefits of NMN supplementation — based on completed human trials, not mouse studies — fall into three categories: NAD+ elevation, metabolic markers, and exercise performance. Everything beyond that is either preliminary or speculative.

NAD+ elevation. This is the one outcome every NMN trial reliably shows. Oral NMN at doses of 250–1,250 mg daily consistently raises blood NAD+ levels by 40–100% within 2–4 weeks. A 2022 study in New England Journal of Medicine (NEJM Evidence) confirmed dose-dependent NAD+ increases in 80 healthy middle-aged adults taking NMN for 60 days. The question is whether higher blood NAD+ translates to functional tissue-level improvements — which requires longer and larger trials.

Metabolic markers. A 2021 Science study from Washington University gave 250 mg NMN daily to 25 postmenopausal prediabetic women for 10 weeks. Skeletal muscle insulin sensitivity improved by approximately 25% (measured by hyperinsulinemic-euglycemic clamp, the gold standard). Fasting insulin and muscle insulin signaling improved. This is the most rigorous metabolic outcome data for NMN to date.

Exercise performance. A 2022 Journal of the International Society of Sports Nutrition trial in recreational runners found that 6 weeks of NMN supplementation (600–1,200 mg daily) improved aerobic capacity — measured by ventilatory threshold during graded exercise testing. The effect was modest (roughly 5–8% improvement) but statistically significant and dose-dependent.

What NMN has NOT been proven to do in humans: reverse aging (no trial has measured biological age as a primary outcome), improve skin quality, prevent cancer, or extend lifespan. These are extrapolations from rodent studies and NAD+ biology, not from human clinical evidence. People who stop NMN often do so because they expected these unproven benefits and were disappointed — a reasonable reaction to unreasonable marketing claims.

Does NMN Have Cancer Risks?

No human study has shown NMN supplementation causes cancer, but the theoretical concern has biological plausibility that has not been fully resolved.

The concern stems from NAD+'s role in cellular energy metabolism. Cancer cells are metabolically hyperactive — they need enormous amounts of NAD+ to sustain rapid proliferation. In theory, raising systemic NAD+ levels could provide fuel to existing pre-cancerous or cancerous cells that have not yet been detected. A 2019 study in Cell Metabolism showed that NAD+ biosynthesis was upregulated in certain tumor types, and inhibiting the NAD+ salvage pathway (via NAMPT inhibitors) slowed tumor growth in animal models.

The counterargument: NAD+ supports DNA repair through PARP1 activation and sirtuin-mediated genomic stability. Low NAD+ levels impair your cells' ability to fix DNA damage — the very process that leads to cancer initiation. So declining NAD+ with age may actually increase cancer risk, and restoring it could be protective against new cancer formation while theoretically problematic for existing tumors.

The practical takeaway: if you have no history of cancer and no active malignancy, the evidence does not suggest NMN supplementation increases cancer risk. If you are currently undergoing cancer treatment, in cancer remission, or have a strong family history of cancer, discuss NMN with your oncologist before supplementing. This is not fear-mongering — it is acknowledging that the cancer-NAD+ relationship is bidirectional and not yet fully characterized in human supplementation contexts.

What Should You Look for When Choosing an NMN Supplement?

Third-party testing, proper storage, and realistic dose labeling are the three non-negotiable criteria. The NMN supplement market is flooded with products that may contain degraded or substituted raw material.

Third-party COA (Certificate of Analysis). NMN degrades when exposed to heat and moisture, converting to nicotinamide (plain vitamin B3) — which is cheap and has none of NMN's NAD+-boosting efficiency. A 2023 analysis by ConsumerLab found that several popular NMN products contained significantly less NMN than labeled, with some containing primarily nicotinamide. Look for brands that publish third-party COAs from independent labs (not their own manufacturer) showing actual NMN purity above 98%.

Storage and packaging. NMN is hygroscopic — it absorbs moisture from air, accelerating degradation. Quality brands ship NMN in opaque, airtight bottles with desiccant packs and recommend refrigeration after opening. Clear glass jars with screw-top lids, stored on a room-temperature shelf for months, will contain degraded NMN regardless of what the label says. Some brands use individually sealed capsule blister packs, which eliminate air exposure per dose.

Dose range. Clinical trials have used 250 mg to 1,250 mg daily. Products offering 100 mg per serving are below the lowest studied dose. Products claiming 2,000+ mg daily are above anything tested in controlled settings. A reasonable starting dose is 250–500 mg daily, increasing to 500–1,000 mg if tolerated and if blood NAD+ testing (available through companies like Jinfiniti) shows suboptimal levels.

Form. Capsules, sublingual tablets, and powder are the three common delivery formats. Sublingual absorption bypasses first-pass liver metabolism, which may preserve more NMN before it reaches target tissues. Powder allows flexible dosing but requires careful measurement. Standard capsules are the most convenient. Liposomal formulations claim enhanced bioavailability but lack comparative clinical trials against standard NMN.

How Much NMN Should You Take Per Day?

The clinically studied range is 250–1,250 mg daily. Most researchers and informed practitioners recommend starting at 250–500 mg and titrating upward based on subjective response and, ideally, blood NAD+ testing.

The dose-response data from human trials shows a clear pattern: NAD+ elevation scales with dose up to approximately 900–1,000 mg, after which additional NMN produces diminishing returns. The Igarashi 2022 NEJM Evidence trial tested 250, 500, and 1,250 mg daily in healthy adults. All doses raised NAD+ levels, with the highest dose producing the greatest increase — but the per-milligram efficiency was highest at 250–500 mg.

Body weight may influence optimal dosing, though no trial has formally established weight-based NMN guidelines. Extrapolating from the animal literature — which typically uses 100–500 mg per kg per day, adjusted for allometric scaling — a 70 kg human would fall in the 250–600 mg range. Heavier individuals may need 500–1,000 mg to achieve equivalent tissue saturation.

Timing also matters. NMN activates sirtuins and circadian clock genes, which are most active during daylight hours. Taking NMN in the morning aligns with your body's natural NAD+ rhythm (NAD+ peaks during waking hours and declines at night). Some users report disrupted sleep when taking NMN in the evening, likely because elevated NAD+ drives sirtuin-mediated metabolic activity at a time when your body is downregulating for sleep. Morning dosing with food is the safest default recommendation.

Are NMN Benefits Different for Men and Women?

The metabolic benefits of NMN appear broadly similar between sexes, but the best clinical evidence we have is specifically in women — the landmark Washington University Science study enrolled only postmenopausal women.

For women, the established evidence centers on insulin sensitivity and metabolic health. The Yoshino 2021 trial showed that NMN improved skeletal muscle insulin sensitivity, glucose disposal, and muscle remodeling gene expression in overweight postmenopausal women. This is relevant because insulin resistance accelerates significantly after menopause due to estrogen decline, and NMN's mechanism addresses this at the cellular level through NAD+-dependent SIRT1 activation.

For men, direct evidence is thinner. The exercise performance trials (Liao 2022, Huang 2023) enrolled mixed-sex cohorts of recreational athletes, and the aerobic capacity improvements did not differ significantly between male and female participants. Testosterone-related effects — a common marketing claim — have no supporting human data for NMN specifically, though NAD+ supports Leydig cell function in animal models.

The honest summary: NMN's core mechanism (raising NAD+ to support mitochondrial function, DNA repair, and sirtuin activity) is not sex-specific. The metabolic benefits may be more pronounced in postmenopausal women because their baseline NAD+ decline is compounded by estrogen loss. For men, the exercise performance and potential metabolic benefits are supported by mixed-cohort data but lack male-specific trials with male-relevant endpoints (testosterone, prostate health, cardiovascular outcomes).

Does NMN Really Work? How to Know if It's Doing Anything

NMN demonstrably raises NAD+ levels in human blood — that is settled. Whether that NAD+ increase produces noticeable subjective changes is where most people's frustration begins, because the timeline and the subtlety of effects do not match supplement marketing expectations.

The problem is detection, not efficacy. If you started taking NMN at age 40 with the goal of "anti-aging," what would success even feel like on a Tuesday afternoon? NAD+ restoration works at the mitochondrial and genomic level — improving ATP production efficiency, supporting DNA repair through PARP1, and activating sirtuin-mediated gene expression. These are processes you cannot feel. You do not sense your mitochondria becoming 15% more efficient. You do not feel a PARP1 enzyme repairing a double-strand DNA break.

What some people do notice — and what clinical trials have measured — are downstream proxies: improved exercise recovery (faster return to baseline heart rate, less delayed-onset muscle soreness), slightly better sleep quality, improved fasting glucose numbers on bloodwork, and sustained energy without caffeine dependence. These effects are modest, gradual, and easily attributed to other lifestyle factors — which is why "I don't feel anything" is the number one reason people quit.

The most objective way to verify NMN is working: test your intracellular NAD+ levels before starting and again at 8–12 weeks. Companies like Jinfiniti offer at-home NAD+ blood tests ($99–149). If your NAD+ level has increased meaningfully (typically 40–100% above baseline on a 250–500 mg daily dose), the supplement is working biochemically regardless of whether you feel different. If NAD+ has not changed, the product quality, dose, or your individual absorption may be the issue.

Should You Take NMN With Resveratrol?

The NMN + resveratrol stack is the most popular NAD+-related combination, driven primarily by David Sinclair's public advocacy. The scientific rationale has merit, but the human clinical evidence supporting the combination over NMN alone is thin.

The theory: NMN provides the raw material (NAD+), while resveratrol activates SIRT1 — the sirtuin enzyme that uses NAD+ as a cofactor. In this model, NMN fills the tank and resveratrol steps on the gas. A 2013 Cell study (Hubbard et al.) showed that resveratrol's ability to activate SIRT1 was dependent on NAD+ availability, suggesting the two compounds are synergistic.

The reality: no published randomized controlled trial has directly compared NMN alone versus NMN + resveratrol in humans with head-to-head outcome measures. The combination is biologically plausible but empirically unproven in humans. Resveratrol itself has a troubled clinical track record — despite thousands of in vitro and animal studies, human trials for resveratrol have produced mixed results across cardiovascular, metabolic, and cognitive endpoints, partly because resveratrol has poor oral bioavailability (less than 1% reaches systemic circulation in most formulations).

If you choose to add resveratrol, use trans-resveratrol (the bioactive isomer) at 250–500 mg daily, taken with a fat-containing meal (resveratrol is lipophilic). Some formulations use micronized or liposomal resveratrol to improve absorption. But understand that you are stacking based on mechanistic logic, not clinical proof — and that NMN alone, at adequate doses with confirmed NAD+ elevation on blood testing, may be sufficient.

What Is the FDA's Current Position on NMN?

As of early 2026, NMN occupies a regulatory gray zone. The FDA issued a determination in 2022 that NMN could not be marketed as a dietary supplement because it had been authorized for investigation as a new drug (Metro International Biotech's NMN clinical trials). However, enforcement has been inconsistent, and NMN products remain widely available for purchase online and in retail stores.

In November 2024, a federal court ruling in the Natural Products Association lawsuit questioned the FDA's interpretation of the exclusion clause, though the ruling did not definitively restore NMN's dietary supplement status. The practical situation as of now: NMN is sold openly by dozens of brands, major retailers stock it, and the FDA has not pursued enforcement actions against NMN sellers. But the legal status remains unresolved, and a future FDA decision could change market availability.

For consumers, this means two things. First, because NMN is not formally regulated as a dietary supplement, quality standards are voluntary — there is no FDA-mandated testing, labeling accuracy requirement, or Good Manufacturing Practice enforcement specific to NMN. This makes third-party testing (from labs like NSF, USP, or independent analytical labs) even more important than for regulated supplements. Second, some people stop taking NMN specifically because of regulatory uncertainty — they interpret the FDA's position as a safety signal. It is not. The FDA's exclusion was a legal/commercial determination (protecting a drug company's investment in clinical trials), not a safety determination. No FDA statement has cited safety concerns with NMN at supplemental doses.

Can You Take NMN Long Term? What the 12-Week Limit Means

All published NMN human trials have lasted 12 weeks or fewer. This does not mean NMN is unsafe beyond 12 weeks — it means no one has formally studied it for longer. The distinction between "unstudied" and "unsafe" is critical, and conflating the two is the most common error in both pro-NMN and anti-NMN discourse.

From a biological perspective, NMN is converted to NAD+ through the salvage pathway — a normal biochemical process that operates continuously in every cell. You are not introducing a foreign compound; you are providing additional substrate for a reaction your body already runs. This is fundamentally different from pharmaceutical drugs that act on receptors, inhibit enzymes, or alter signaling cascades in dose-dependent and potentially cumulative ways.

That said, legitimate open questions exist about long-term NAD+ elevation. PARP1 activation (DNA repair) and sirtuin activation (gene expression regulation) are context-dependent — they can be beneficial (protecting against DNA damage) or potentially problematic (in the hypothetical scenario of fueling undetected pre-cancerous cell growth). The only way to resolve these questions is through long-term human studies, several of which are underway but have not yet published results.

The pragmatic approach for people currently taking NMN long-term: maintain regular health monitoring (annual bloodwork including complete metabolic panel, CBC, and cancer screening appropriate for your age and sex), use a third-party-tested product at a dose within the studied range (250–1,000 mg daily), and stay current with published research. If a long-term study eventually identifies a concern, you will have a clean health baseline for comparison and can make an informed decision about continuing.

Does the Brand of NMN Supplement Matter?

More than most supplement categories, yes. NMN quality varies dramatically between brands because of the stability problem: NMN degrades to nicotinamide (plain niacin) when exposed to heat, moisture, or light. A product that tests at 99% purity at the factory can drop to 70–80% purity on a warehouse shelf within months if improperly stored. Independent testing by ConsumerLab and third-party analyses shared in the longevity research community have found that some NMN products contain less than half the labeled NMN content. The brands that consistently test well share three characteristics: they manufacture in GMP-certified facilities, publish batch-specific COAs from ISO 17025-accredited labs, and ship in opaque, sealed packaging with desiccant. Paying $30 for 60 capsules of degraded NMN is more expensive than paying $50 for 60 capsules of verified NMN — because the cheap product gives you zero functional NMN per dollar.

Why YourHealthier NMN

Our NMN provides 500 mg of nicotinamide mononucleotide per serving at ≥98% verified purity, third-party tested for identity, potency, and heavy metals, with batch COAs on our Lab Results page. The 500 mg dose sits right in the evidence-aligned range, so you are not overpaying for NAD+ you cannot use.

Related reading

• NMN vs NR: Which NAD+ Precursor Is Better? (2026 Data)
• NMN Dosage: How Much Per Day? 250mg vs 600mg vs 1000mg
• NMN Side Effects: What the Clinical Trials Report
• Best Time to Take NMN: Morning or Night?
• What Is NMN? Benefits, NAD+ & Aging Research

Frequently asked questions

Why I Stopped Taking NMN?

The most common reasons people cite are cost (quality NMN runs $40 to $80/month), lack of noticeable subjective effects within the first 30 to 60 days, and confusion over the 2022 FDA stance that temporarily pulled NMN from supplement shelves. Some users also report mild GI discomfort at doses above 500 mg. Objective biomarkers like NAD+ blood levels do rise with consistent use, but most consumers judge supplements by how they feel, not by lab work.

References

1. Christen S, Redeuil K, Goulet L, et al. The differential impact of three different NAD+ boosters on circulatory NAD and microbial metabolism in humans. Nature Metabolism. 2026. PubMed
2. Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults. GeroScience. 2023;45:29-43. PubMed
3. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372:1224-1229. PubMed
4. Zhang J, Poon ETC, Wong SHS. Efficacy of oral NMN supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis. Critical Reviews in Food Science and Nutrition. 2025;65(22):4382-4400. PubMed
5. Song Q, Zhou X, Xu K, et al. The safety and antiaging effects of nicotinamide mononucleotide in human clinical trials: an update. Advances in Nutrition. 2023;14(6):1416-1435. PubMed
6. US FDA declares NMN lawful in dietary supplements. NutraIngredients. 2025. Article

Disclosure: YourHealthier sells NMN supplements. This article is written by our editorial team based on peer-reviewed research. We cite only published clinical trials and regulatory sources and disclose where the evidence is limited. Our goal is to help you make an informed decision, not to pressure a purchase. See our Editorial Policy.

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not intended as medical advice.

Why People Quit NMN - and the Reality

Metric	Value
Top reason people quit	no obvious feeling
Does it raise NAD+?	yes (12+ RCTs)
FDA ban (2022)	reversed in 2025
Give it before judging	8-12 weeks
Source: YourHealthier · Christen 2026 (Nature Metabolism); FDA Sept 2025; 12+ human trials

Chart: Why People Quit NMN and the Reality. Data: Top reason people quit: no obvious feeling; Does it raise NAD+?: yes (12+ RCTs); FDA ban (2022): reversed in 2025; Give it before judging: 8-12 weeks. Source: Christen 2026 Nature Metabolism; FDA September 2025; 12+ human trials.