NAD+ (nicotinamide adenine dinucleotide)
NAD+: What The Studies Actually Say
Every cell makes NAD+. Almost every trial in people tested pills the body turns into it, not the shots and drips being sold. The pills raise blood levels, but the health results are mixed. A 2026 review found no trials of NAD+ shots or drips for anti-aging or wellness. Here is what the studies actually found.
Updated 22 September 2026
Before you read this
This page explains what published studies found. That is all it is. It is not medical advice, and it is not instructions for using anything. Nothing here is meant to find, treat, cure or stop any illness. The compounds discussed on this site, retatrutide included, are not approved by the FDA for use in people. Research compounds are sold for laboratory use only — not for use in humans or animals. A study tells you what happened to the people in it. It does not tell you what would happen to you. What you do with what you read here is your responsibility, so talk to a doctor first. This page is published by Ascend Vials, which sells research compounds.
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Every cell in your body makes NAD+. Nobody argues about that part.
The real question is whether a drip, a shot or a pill of it does anything for you. Here is what the research actually found. Every claim has a link. Read them yourself.
The 30-second version
- NAD+ is a helper molecule every cell makes from forms of vitamin B3. Older people tend to have less. Nobody has shown the drop causes aging.
- Almost every trial in people tested pills called NR and NMN, which the body turns into NAD+. Not NAD+ shots or drips.
- The pills reliably raise NAD+ in blood. The health results are mixed and often zero.
- A 2026 review found no trials of NAD+ shots or drips for anti-aging or wellness. In the only published study that tracked a drip, blood NAD+ did not move for the first 2 hours.
- In one small clinic review, all 6 people given an NAD+ drip had cramping, nausea, vomiting or chest pressure during it.
- No NAD+ drug is FDA-approved. China has a low-dose prescription NAD+ shot for a few medical uses. We found no country that approves it for anti-aging or wellness.
- Nothing sold online has been shown to match what the studies used. No study has checked.
What it is
NAD+ is short for nicotinamide adenine dinucleotide. It is a helper molecule that many enzymes need in order to work. Your cells make it from forms of vitamin B3 and from tryptophan, an amino acid in food. It helps turn food into fuel. And enzymes tied to DNA repair and the immune system cannot work without it. Review, 2021
Older people tend to have less. NAD+ fell with age in 49 skin samples, from newborns to age 77. PLoS One, 2012 It also fell in blood plasma from people aged 20 to 87. Study, 2019 In muscle, it was lowest in older adults who had trouble moving. Nat Aging, 2022
That is a link, not proof of cause. Each person was measured once. Nobody has shown that less NAD+ makes you age. Nat Aging, 2022 You may have read that NAD+ halves by middle age. We could not find a study in people that shows that number.
Three different things are sold as "NAD+":
- NAD+ itself, as IV drips, shots under the skin or into muscle, nasal sprays and pills.
- NR (nicotinamide riboside, trademarked as Niagen), a pill the body turns into NAD+.
- NMN (nicotinamide mononucleotide), another pill the body turns into NAD+.
Each one has different evidence. Ageing Res Rev, 2026
Almost every study tested pills, not shots
A 2026 review gathered NAD+ booster studies from 2010 to October 2025. It found 33 in people, 28 of them randomized. NR and NMN pills reliably raised NAD+ and were generally well tolerated. Their effects on health measures were mixed and often zero. It found no outcome trials of NAD+ drips or muscle shots for anti-aging or wellness. Ageing Res Rev, 2026
| NAD+ drip or shot | NR pills | NMN pills | |
|---|---|---|---|
| Biggest placebo trial on this page | 180 people, at a tiny dose | 140 people | 80 people |
| Raised NAD+ in blood? | Yes, but only after 2 hours of drip (8 men) | Yes | Yes |
| Raised NAD+ in muscle? | Never measured | No | No |
| Anti-aging or wellness trials | None | Several, mixed or null | Several, mixed or null |
| US status | No approved drug | Food ingredient (2016) | Supplement, with FDA notice (2025) |
Read the whole table. The form sold in vials has the least evidence of the three. When someone quotes an "NAD+ study," check which one it tested.
Sources: Review, 2026 · Drip study, 2019 · Heart trial, 2026 · NR trial, 2019 · NR muscle, 2019 · NMN trial, 2023 · NMN muscle, 2021
What happens to an NAD+ drip in your blood
Only one published study has tracked it. 8 healthy men got 750 mg of NAD+ dripped over 6 hours, and 3 others got salt water. Front Aging Neurosci, 2019
For the first 2 hours, NAD+ in their blood did not change at all. The authors wrote that it was "rapidly and completely removed." By the end, blood NAD+ was up about 400%. So were the pieces it breaks down into, and NAD+ in urine was up 538%. Part of each dose was being broken down or flushed out. Front Aging Neurosci, 2019
The study measured blood and urine only. Nobody has shown that NAD+ from a drip gets inside your muscles, brain or organs. The drips were given at a wellness center that uses IV NAD as a therapy, and its medical director was an author. Front Aging Neurosci, 2019 We found no published study in people of NAD+ shots under the skin.
A second trial, not yet published in a journal, compared drips in healthy adults. At 3 hours, NAD+ in dried blood was higher after an NR drip than after an NAD+ drip. medRxiv, 2024 It comes from ChromaDex, which sells NR.
The one drip trial that tested a medical result
In China, 180 adults with hearts weakened by blocked arteries kept their usual treatment. Half also got 10 mg of NAD+ into a vein daily for a week. Half got a placebo. It is the only randomized NAD+ drip trial we found with a medical result. Am J Cardiovasc Drugs, 2026
After a month, the heart's pumping score rose 4.5 points on NAD+ and 2.3 on placebo. That gap was statistically significant. Over 6 months, serious heart and stroke events hit 14.6% against 24.7%, and heart-failure hospital stays 13.5% against 23.6%. Neither of those gaps was statistically significant, so they could be chance. It was one hospital, and the authors call for bigger trials. Am J Cardiovasc Drugs, 2026
The dose was 10 mg a day. The drip studies above used 500 to 750 mg. Nobody knows whether this result says anything about wellness drips.
What the pills did
In the biggest pill trial, 140 overweight adults took NR or a fake pill for 8 weeks. Blood NAD+ rose more at higher doses. Sci Rep, 2019
Other trials agree: blood NAD+ goes up. Nat Commun, 2018 · GeroScience, 2024 · Nat Commun, 2023
But blood is not muscle. In 12 men aged 70 to 80, NR did not significantly raise muscle NAD+: 210 against 197. Grip strength did not change. Cell Rep, 2019 NMN did not raise muscle NAD+ in 25 women either. Science, 2021 In 30 people with new Parkinson's, NR did raise NAD+ in the brain, by very different amounts from person to person. Cell Metab, 2022
Did anyone get healthier?
| What was tested | People | How long | Against placebo |
|---|---|---|---|
| NR: insulin sensitivity, obese men | 40 | 12 weeks | No change |
| NR: muscle function, men aged 70-80 | 12 | 3 weeks | No change |
| NR: memory and thinking | 20 | 10 weeks | No change |
| NR: walking, leg artery disease | 90 | 6 months | 17.6 m farther in 6 minutes |
| NMN: muscle insulin sensitivity | 25 | 10 weeks | Up 25% |
| NMN: weight, overweight adults | 30 | 4 weeks | 1.9 kg lighter |
| NMN: amateur runners | 48 | 6 weeks | Some gains. VO2max no change |
| NMN: walking, healthy adults | 80 | 60 days | Walked farther. Maker paid |
Sources, top to bottom: 2018 · 2019 · 2024 · 2024 · 2021 · 2023 · 2021 · 2023
Read the whole table. The biggest had 90 people, and none ran past 6 months. Three found nothing. The walking trial's authors say a bigger trial is needed. Nat Commun, 2024
One NMN trial also reported a younger "biological age." That came from a calculator that estimates age from 19 routine blood tests. It is a model's guess, not a health result. GeroScience, 2023
The anti-aging part was only shown in mice
In mice, NMN given for a year slowed age-related weight gain and improved energy use, activity and blood sugar control. Cell Metab, 2016 Raising NAD+ in old mice brought the work of their mitochondria, the cell's power plants, back to young levels. Cell, 2013 One study found NR made mice live longer. Science, 2016
Then the most careful test said no. A US government program gave NR to nearly 300 genetically mixed mice at three labs. It did not significantly change lifespan in either sex. Aging Cell, 2021 An NMN study, not yet peer reviewed, found longer lives in female mice only. bioRxiv, 2024
No study has measured lifespan, or any proven measure of aging, in people. Ageing Res Rev, 2026
What to expect
Drips. A clinic chain reviewed its records of people given four daily drips of NAD+ or NR. Front Aging, 2026
| NAD+ drip | NR drip | |
|---|---|---|
| People | 6 | 8 |
| Side effects during the drip | 6 of 6, moderate to severe | 5 of 8, milder |
| Average time per drip | 97 minutes | 37 minutes |
On NAD+, people had cramping, diarrhea, nausea, vomiting, a racing heart, throat pain and chest pressure. It stopped when the drip stopped. On NR, it was mostly tingling. Liver, kidney and thyroid blood tests did not change significantly. Front Aging, 2026 The study was tiny and not randomized. The clinic chain paid for it and employed every author.
The ChromaDex preprint also found more, and worse, drip side effects with NAD+ than with NR. NAD+ also raised white blood cells, which the authors say suggests inflammation. medRxiv, 2024 In the slow 6-hour study, none of the 8 men had side effects. Front Aging Neurosci, 2019
Contaminated drips. FDA has reports of severe chills, shaking and vomiting after NAD+ injections, and some patients needed medical care. FDA says that fits endotoxin, a toxin from bacteria. It warns that pharmacies are making drips from food-grade NAD+. FDA, 2024
Pills. In the 140-person trial, NR side effects were no more common than on the fake pill, with no flushing. Sci Rep, 2019 At a very high dose, homocysteine, a blood marker, rose slightly at first. Nat Commun, 2023 In the 6-month walking trial, 39% on NR had diarrhea, against 28% on placebo. Nat Commun, 2024
Two cancer warnings, both in mice. In mice primed for pancreatic cancer, the authors conclude NMN sped the cancer up. Nat Cell Biol, 2019 In mice with an aggressive breast cancer, NR raised cancer rates and spread to the brain. Biosens Bioelectron, 2023 The NMN lifespan study found no rise in tumors. bioRxiv, 2024 No study in people has tested this.
Athletes. Anti-doping rules ban any drip or injection over 100 mL in 12 hours, whatever is in it, outside hospital stays, surgery, clinical studies or an approved exemption. USADA
Is it approved anywhere?
- United States: no. We found no FDA-approved NAD+ drug. Drugs@FDA In 2019, FDA proposed keeping NAD off the list of ingredients pharmacies may use. It said NAD breaks down easily, its safety data were too thin, and no studies supported the one use put forward. Federal Register, 2019 Its May 2026 list still puts NAD "under evaluation." FDA list, 2026 For now, FDA says it does not intend to act against pharmacies using it, if they meet its conditions. FDA For large outsourcing pharmacies, FDA says NAD+ is not on their list, so drugs they make from it do not qualify for their legal exemptions. FDA warning letter, 2026
- The pills in the US. In 2016, FDA had "no questions" about NR as a vitamin B3 source in some foods and drinks. FDA In 2025, FDA said NMN can be a dietary supplement, with notice to FDA first. That is from a law firm's summary; we could not get FDA's letters. Venable, 2025
- European Union. We found no approval for NAD+ shots. NR is an authorised novel food. EU regulation, 2020 EFSA judged NMN safe up to a daily limit in May 2026. We could not confirm a final EU approval. EFSA, 2026
- Australia and New Zealand. NR is approved as a form of vitamin B3 in foods for special medical purposes. FSANZ, 2021
- China: a prescription drug, Coenzyme I for Injection. Its label lists low white blood cell counts (as an add-on), coronary heart disease and myocarditis. Its 5 mg dose is 100 to 150 times smaller than the drip studies used. Our source is a drug-database copy of the label, not the official registry. Label The 6-hour drip study called 750 mg common in clinics. Front Aging Neurosci, 2019
We found no country that approves NAD+ for anti-aging, energy or "wellness" drips.
What is still unknown
- Whether NAD+ from a drip or shot reaches your tissues. Front Aging Neurosci, 2019
- Shots under the skin. We found no published data in people.
- Repeated high-dose drips. We found no controlled study of them.
- Energy, aging, memory or addiction. No outcome trials of drips. Ageing Res Rev, 2026 We found no randomized trial for addiction or withdrawal on PubMed or ClinicalTrials.gov.
- A year-long NR trial in 410 people with early Parkinson's finished in June 2025. No results yet. Trial record
- Cancer risk in people. The mouse results point both ways.
- Pregnancy and breastfeeding. Left out of most trials. Europe's food safety agency excluded them from its NMN safety finding. It also noted effects on reproductive organs in a rat study. EFSA, 2026
What is in the bottle is not what was studied
One more thing.
Every result on this page came from the NAD+, NR or NMN each study used, given to the people in it.
No study has ever shown that a product sold online as "NAD+" is the same thing. Not the same purity. Not the same strength. Not proof it is sterile.
Here is what that can cost. In January 2026, FDA wrote to a large outsourcing pharmacy. Three patients given its NAD+ from the same vial had been sent to the ER with low blood pressure and uncontrollable shaking. An unopened vial from that batch held 3,360 EU/mL of bacterial endotoxin. The firm had not tested the finished product. FDA warning letter, 2026 FDA also says NAD breaks down with light, moisture and room temperature. Federal Register, 2019
So take every number on this page for what it is. It describes what each study used, in the people they studied. It describes nothing else.
How to check a number yourself
You are going to see more numbers about NAD+. In a reel. In a comment. On somebody's store page.
Here is how to tell a real one from a marketing one. Five questions. About ten seconds each.
1. Is there a link to a study, and which NAD+ did it test?
A real number comes from a paper you can open. No link means it is a claim, not a result. Search on pubmed.gov yourself. You will find plenty of NAD+ papers, so check two things. Was it done in people or in mice? And was it NAD+ itself, NR or NMN? A pill study tells you about the pill.
2. How big was it, and how long did it run?
Small studies swing. The only published study that tracked an NAD+ drip gave it to 8 people. No pill trial in our table ran past 6 months.
3. Was there a group that got nothing?
The fake treatment is the whole point. In the heart trial, the placebo group's pumping score rose too, by 2.3 points. Without that group, NAD+ would have looked about twice as good.
4. Did it measure how people did, or a lab number?
More NAD+ in your blood is a lab number. It is not the same as feeling better, or aging slower. And a "biological age" from a calculator is an estimate, not a result.
5. Who paid for it?
On this page, the NR maker paid for the 140-person trial and wrote the drip preprint. A clinic chain paid for the drip record review. The 6-hour drip study was done at a clinic that uses NAD drips. That does not make them wrong. It means someone else should check.
Now run those five on this page
Every number above links to the paper it came from. The study sizes and lengths are in the tables. You were told which studies tested pills and which tested drips, and who paid.
The claims you hear most about NAD+ drips, like more energy, slower aging or help with addiction, have no controlled trial behind them.
That is the whole difference: a number you can check, and a number you are asked to believe.
This page has a date on it, near the top. When new studies publish, or FDA decides, this page changes.
Read the studies yourself
- NAD+ booster review, 2026 — the main one · biology review, 2021
- Age: skin, 2012 · plasma, 2019 · muscle, 2022
- Drips: 6-hour study, 2019 · preprint, 2024 · clinic records, 2026 · heart trial, 2026
- NR: 8 weeks, 2019 · older adults, 2018 · obese men, 2018 · muscle, 2019 · Parkinson's, 2022 · high dose, 2023 · memory, 2024 · walking, 2024 · Parkinson's trial record
- NMN: insulin, 2021 · walking, 2023 · runners, 2021 · weight, 2023
- Mice: NMN, 2016 · mitochondria, 2013 · NR lifespan, 2016 · NIH lifespan test, 2021 · NMN preprint, 2024 · pancreatic cancer, 2019 · breast cancer, 2023
- FDA: 2019 proposal · pharmacy ingredients · list, 2026 · alert, 2024 · warning letter, 2026 · NR · Drugs@FDA
- NMN law-firm summary, 2025 · EU NR regulation, 2020 · EFSA NMN, 2026 · FSANZ, 2021 · China label · USADA
Everything above describes what studies gave to enrolled people under a doctor's or researcher's care. This is not advice, a plan, or instructions. NAD+ is not an FDA-approved drug. China licenses a low-dose NAD+ injection for specific medical uses, and none of the approvals we found covers anti-aging or wellness. Research compounds are not for human or animal use.