NAD Supplements: What Actually Raises NAD+ Levels
NAD supplements that hold NR or NMN raised NAD+ in every placebo-controlled trial we read that measured blood or blood cells. One trial that measured muscle instead found no change there. Niacin did too. For pills that hold NAD+ itself, plain or liposomal, we found no human trial that measured blood levels at all. And a higher blood level has not yet been shown to make people healthier.
The short version
- Raised blood NAD+: NR and NMN in several trials, niacin in one.
- No blood data found: plain NAD+ pills and liposomal NAD+.
- Not shown: that the blood rise brings a health result, or that it reaches muscle.
This page is about pills only. Food, exercise and sleep are in our guide on how to increase NAD naturally, and shots are on the NAD+ dosage chart.
Sources: Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Yi L and others, sixty-day dose-ranging NMN trial in eighty adults, GeroScience, 2023. PMID 36482258; Pirinen E and others, niacin study in adult-onset mitochondrial myopathy, Cell Metabolism, 2020. PMID 32386566; PubMed search for trials of oral NAD+ or NADH, run 23 October 2026: 4 records, none measuring NAD+ in blood; Gallagher C and Emmanuel OO, systematic review of 113 NAD studies, Ageing Research Reviews, 2026. PMID 41655607
What is in an NAD supplement?
NAD+ is a helper molecule that every cell uses to make energy and repair itself. The body builds it from smaller parts. Most supplements sell one of those parts, called a precursor, rather than NAD+ itself.
- NR (nicotinamide riboside): a vitamin the body turns into NAD+. It was the main ingredient on 5 of the 7 product pages we read.
- NMN (nicotinamide mononucleotide): another precursor the body converts to NAD+.
- Niacin: the classic B3 vitamin, known for causing flushing.
- NAD+ or NADH: the finished molecule, sometimes sold in a liposomal coating.
The form matters, because the trial evidence is not shared between them. A study of NR says nothing direct about an NAD+ capsule. For a closer look at the two precursors people weigh most, see NMN vs NAD+.
Sources: Trammell SA and others, first human NR dose study plus mouse work, Nature Communications, 2016. PMID 27721479; Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Okabe K and others, twelve-week NMN trial in thirty healthy adults, Frontiers in Nutrition, 2022. PMID 35479740; Pirinen E and others, niacin study in adult-onset mitochondrial myopathy, Cell Metabolism, 2020. PMID 32386566; Igarashi M and others, NMN trial in healthy older men, npj Aging, 2022. PMID 35927255; Our own read of seven public NAD supplement product pages, 23 October 2026
Which oral forms raised NAD+ in human trials
We read each trial below on 23 October 2026, from the abstract or the full paper. The table keeps the form, the people, the length, where NAD+ was measured and what happened. No outside page we found puts every oral form in one table like this.
These are the amounts given in the published human trials named in the last column, with what each one measured:
| Form | Who and how long | Amount given | Measured in | What happened to NAD+ | Trial |
|---|---|---|---|---|---|
| NR | 1 person (pilot), then 12 healthy adults. Single doses. | 100, 300 and 1,000 mg once | Blood | Up to 2.7 times higher in the one-person pilot; rises tracked the dose | Trammell 2016 |
| NR | 8 healthy adults. Open label, 9 days. | 250 mg rising to 1,000 mg twice a day | Whole blood | About 100% higher at steady state | Airhart 2017 |
| NR | 30 healthy adults aged 55 to 79. Placebo crossover, 6 weeks each. | 500 mg twice a day | White blood cells | About 60% higher than placebo | Martens 2018 |
| NR | Overweight adults. Placebo controlled, 8 weeks. | 100, 300 or 1,000 mg a day | Whole blood | 22%, 51% and 142% higher by dose | Conze 2019 |
| NR | 40 obese men. Placebo controlled, 12 weeks. | 1,000 mg twice a day | Muscle | No change in muscle NAD+ | Dollerup 2020 |
| NMN | Women with prediabetes after menopause. Placebo controlled, 10 weeks. | 250 mg a day | White blood cells | Higher after 10 weeks, not after placebo | Yoshino 2021 |
| NMN | 30 healthy adults. Placebo controlled, 12 weeks. | 250 mg a day | Whole blood | Significantly higher | Okabe 2022 |
| NMN | Healthy older men. Placebo controlled, 6 or 12 weeks. | 250 mg a day | Whole blood | Significantly higher | Igarashi 2022 |
| NMN | 80 healthy middle-aged adults. Placebo controlled, 60 days. | 300, 600 or 900 mg a day | Blood | Higher in every NMN group; highest at 600 and 900 mg | Yi 2023 |
| NMN | 11 healthy middle-aged men. Open label, 8 weeks. | 250 mg a day | White blood cells | Rose over the 8 weeks | Yamaguchi 2024 |
| Niacin | People with a mitochondrial muscle disease, plus controls. Open label, 4 to 10 months. | Raised step by step to 750 to 1,000 mg a day | Blood | Up to 8 times higher | Pirinen 2020 |
| NADH with CoQ10 | 73 people with chronic fatigue syndrome. Placebo controlled, 8 weeks. | 20 mg NADH with 200 mg CoQ10 a day | White blood cells | NAD+/NADH ratio higher; NAD+ level itself not reported as raised (two ingredients) | Castro-Marrero 2015 |
Disclaimer: these are the amounts given in short, monitored studies, shown to report what was measured. They are not a dose for you, and a rise in a blood marker is not a proven health benefit. Per the FDA, a supplement maker picks its own serving size, and that choice needs no FDA approval.
Counted by form, the record looks like this. Of the trials above, NR raised NAD+ in blood or blood cells in 4 of 5; the fifth measured muscle only. NMN did so in 5 of 5. Niacin has one trial that raised NAD+ in blood. The NADH mix has one trial, which reported a higher NAD+ to NADH ratio, not a higher NAD+ level. Plain and liposomal NAD+ have 0.
Several of these trials were paid for or supplied by companies that sell the ingredient. The Conze trial, for one, was funded by the maker of the NR it tested. That does not make the results wrong, but it is worth knowing.
Sources: Trammell SA and others, first human NR dose study plus mouse work, Nature Communications, 2016. PMID 27721479; Airhart SE and others, open-label study of oral NR in eight healthy volunteers, PLoS One, 2017. PMID 29211728; Martens CR and others, NR crossover trial in adults aged 55 to 79, Nature Communications, 2018. PMID 29599478; Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Dollerup OL and others, 12-week NR muscle biopsy trial in obese, insulin-resistant men, Journal of Physiology, 2020. PMID 31710095; Yoshino M and others, 10-week NMN trial in women with prediabetes, Science, 2021. PMID 33888596; Okabe K and others, twelve-week NMN trial in thirty healthy adults, Frontiers in Nutrition, 2022. PMID 35479740; Igarashi M and others, NMN trial in healthy older men, npj Aging, 2022. PMID 35927255; Yi L and others, sixty-day dose-ranging NMN trial in eighty adults, GeroScience, 2023. PMID 36482258; Yamaguchi S and others, eight-week open-label NMN study in Japanese men, Endocrine Journal, 2024. PMID 38191197; Pirinen E and others, niacin study in adult-onset mitochondrial myopathy, Cell Metabolism, 2020. PMID 32386566; Castro-Marrero J and others, eight-week CoQ10 and NADH trial in chronic fatigue syndrome, Antioxidants and Redox Signaling, 2015. PMID 25386668; FDA supplement questions page, updated 27 August 2026 and read by us on 23 October 2026. It states that, by law, the agency does not approve dietary supplements or their labeling
Does a bigger pill raise NAD+ more?
Up to a point. One trial gives a clean test, because it gave three different amounts of NR for eight weeks. We divided each group's rise in blood NAD+ by its daily amount. That is our own arithmetic on the published averages.
The 2019 Conze trial in Scientific Reports gave NR at these daily amounts, with these average rises in whole blood NAD+:
100 mg a day: 22% higher, or 22 points per 100 mg
300 mg a day: 51% higher, or 17 points per 100 mg
1,000 mg a day: 142% higher, or 14.2 points per 100 mg
Disclaimer: this is our own division of three published group averages, to show the shape of the curve. It is not a dose for anyone, and the trial did not test whether a bigger rise helps health.
So the total rise grew with the amount, but each extra step added less than the one before. The 2023 NMN trial points the same way: its two higher groups ended up close together. Neither trial tested what those extra points do for the body.
Sources: Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Yi L and others, sixty-day dose-ranging NMN trial in eighty adults, GeroScience, 2023. PMID 36482258
A higher blood level is not the same as a health benefit
Most trials measured NAD+ in blood, because blood is easy to sample. But blood is not where most of the work happens. In a 12-week trial in 40 obese men, NR left NAD+ inside muscle unchanged. It also did not change how well their muscle cells made energy.
A 2026 review of 33 human studies sums up the pattern. Oral NR and NMN raised NAD+ markers in a steady way and were well tolerated over weeks to months. Results for fitness, metabolism, blood vessels and other health goals were mixed and often null. One NMN trial did find better insulin action in the muscle of women with prediabetes. That is one trial in one group, not a general result.
Sources: Dollerup OL and others, 12-week NR muscle biopsy trial in obese, insulin-resistant men, Journal of Physiology, 2020. PMID 31710095; Gallagher C and Emmanuel OO, systematic review of 113 NAD studies, Ageing Research Reviews, 2026. PMID 41655607; Yoshino M and others, 10-week NMN trial in women with prediabetes, Science, 2021. PMID 33888596
What about plain and liposomal NAD+ pills?
Here the record goes quiet. On 23 October 2026 we ran two PubMed searches, one for liposomal NAD taken by mouth in people and one for trials of oral NAD+ or NADH. Between them they returned five records. None measured NAD+ in the blood after a plain or liposomal NAD+ pill.
The oral NADH trials that turned up scored symptoms, such as fatigue or memory, not blood levels. The one study with a blood-cell result mixed NADH with CoQ10, so the effect cannot be pinned on NADH. A missing study is not proof that a product fails. It does mean a claim that it raises NAD+ rests on no published human measurement we could find.
Sources: PubMed search for liposomal NAD taken by mouth in humans, run 23 October 2026: 1 record, a lab study of injected gel beads; PubMed search for trials of oral NAD+ or NADH, run 23 October 2026: 4 records, none measuring NAD+ in blood; Castro-Marrero J and others, eight-week CoQ10 and NADH trial in chronic fatigue syndrome, Antioxidants and Redox Signaling, 2015. PMID 25386668
What seven product pages told buyers
On 23 October 2026 we read seven public NAD supplement product pages from brands that sell online. We only read them. We bought nothing and did not sign in. A script counted what each page showed, and we name no store.
| What we checked | Pages |
|---|---|
| Main NAD ingredient was NR | 5 of 7 |
| Main NAD ingredient was NMN | 1 of 7 |
| Main ingredient was NAD+ itself | 1 of 7 |
| Printed the US line that the FDA has not evaluated its claims | 7 of 7 |
| Named a published human study by its authors | 2 of 7 |
| Cited studies of a different ingredient than the one in the bottle | 1 of 7 |
| Claimed outside or third-party testing | 6 of 7 |
The one product made of NAD+ itself listed NR trials as its clinical research. Those studies tested a different molecule. That is the gap the table above shows, turning up on a real shelf. This is our own snapshot of seven pages, not a survey of the market.
Sources: Our own read of seven public NAD supplement product pages, 23 October 2026
Side effects, and how the US treats these pills
In the short trials, side effects were few. The eight-week NR trial saw no flushing and no more side effects than placebo. A 2026 review pooled 15 NMN trials, and 10 of them gave safety data. In those 10, it found no rise in side effects, serious events or liver test changes. A 2024 review of NADH and precursor trials listed muscle pain, headache, tiredness and poor sleep, none rated serious.
Niacin is the exception people notice. The 2022 NMN paper notes that niacin can cause nausea and flushing, which limits how much people can take. Nearly all of these trials ran for weeks or months, so long-term safety is still an open question.
In the US, these are sold as dietary supplements, not drugs; all seven pages we read carried the supplement line. The FDA says that, by law, it does not approve dietary supplements or their labels. For NMN, the FDA answered a petition from the Natural Products Association and the Alliance for Natural Health USA, in docket FDA-2023-P-0872. The docket files that reply, dated 29 September 2025, as a partial approval and partial denial. We could not open the letter itself on 23 October 2026, so we do not quote it.
Sources: Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Yang W and others, review and pooled analysis of randomized NMN trials taken by mouth, Nutrients, 2026: 15 trials included, 10 of them in the safety analyses. PMID 42514320; Gindri IM and others, systematic review of ten NAD and NADH trials, American Journal of Physiology (Endocrinology and Metabolism), 2024. PMID 37971292; Igarashi M and others, NMN trial in healthy older men, npj Aging, 2022. PMID 35927255; FDA supplement questions page, updated 27 August 2026 and read by us on 23 October 2026. It states that, by law, the agency does not approve dietary supplements or their labeling; US FDA, "Response Letter from FDA HFP to Natural Products Association and Alliance for Natural Health USA," docket FDA-2023-P-0872, document FDA-2023-P-0872-2754, filed 29 September 2025 and listed by the docket as a partial petition approval and denial. Docket record read 23 October 2026 through the regulations.gov API; the letter download returned a block page to us that day; Our own read of seven public NAD supplement product pages, 23 October 2026
Common questions
What does the NAD supplement do?+
Most of these pills hold a building block, such as NR or NMN, that the body turns into NAD+. In the trials on this page, those building blocks raised NAD+ in blood or blood cells. A 2026 review of 33 human studies found the blood rise was steady, but effects on fitness, metabolism and aging markers were mixed and often absent.
What is the downside of taking NAD?+
The short trials found few problems. An eight-week NR trial saw no flushing and no more side effects than placebo, and a 2026 review of 15 NMN trials found no rise in side effects or liver test changes. The real gaps are length and proof: most trials ran 12 weeks or less, and a higher blood level has not been shown to make people healthier.
Is NAD just vitamin B3?+
Not quite. NAD+ is a helper molecule the body builds from forms of vitamin B3. Niacin and nicotinamide are classic B3 forms, and NR is described in research as an NAD+ precursor vitamin too. NMN is another precursor the body converts to NAD+. So the pills feed the same pathway, but NAD+ itself is the end product.
What is better, NR or NMN?+
None of the trials we read compared them head to head. Both raised NAD+ in blood or blood cells in placebo-controlled trials, and neither has shown a clear health benefit yet. Our NMN vs NAD+ guide covers how the two precursors differ.
What happens if you take NAD every day?+
Most trials gave their pills daily for days up to about three months, and blood NAD+ stayed higher while people kept taking them. What happens over years has not been studied in these trials. The 2020 niacin study ran longest, at up to 10 months, in people with a rare muscle disease.
Does liposomal NAD+ work better?+
We found no human trial that measured blood NAD+ after a liposomal or plain NAD+ pill, in two PubMed searches on 23 October 2026. The oral NADH trials we found scored symptoms, not blood levels. So any claim that a liposomal product raises NAD+ better is not backed by a published human measurement we could find.
Sources: Gallagher C and Emmanuel OO, systematic review of 113 NAD studies, Ageing Research Reviews, 2026. PMID 41655607; Conze D, Brenner C and Kruger CL, eight-week NIAGEN safety trial in overweight adults, Scientific Reports, 2019. PMID 31278280; Yang W and others, review and pooled analysis of randomized NMN trials taken by mouth, Nutrients, 2026: 15 trials included, 10 of them in the safety analyses. PMID 42514320; Trammell SA and others, first human NR dose study plus mouse work, Nature Communications, 2016. PMID 27721479; Pirinen E and others, niacin study in adult-onset mitochondrial myopathy, Cell Metabolism, 2020. PMID 32386566; PubMed search for liposomal NAD taken by mouth in humans, run 23 October 2026: 1 record, a lab study of injected gel beads; PubMed search for trials of oral NAD+ or NADH, run 23 October 2026: 4 records, none measuring NAD+ in blood
Related pages
This page sums up published human trials of oral NAD supplements. It is background reading, not medical advice. It backs no product and sets no amount for any reader. Talk to a doctor before starting a supplement, more so if you take other medicines.