# What is NAD+, and what are NMN and NR?

> NAD+ is a coenzyme that every cell uses to turn food into energy, and NMN and NR are related molecules the body converts into it. No trial has shown that any of them slows aging in people, a 2026 trial linked NR to worse Parkinson symptoms than placebo, and NAD+ is not FDA-approved for any use.

The journal is published by Rovere, a telehealth service that sells some of the treatments discussed here. Articles are general information, not medical advice. Only a licensed clinician can say whether a treatment is right for you.

- Topic: Compounds
- Web page: https://roverehealth.com/journal/nad-plus

## Key points

- NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell, used to turn food into energy and to repair DNA. It is built from two nucleotides, not amino acids, so it is not a peptide.
- Swallowed NMN and NR raise NAD+ in the blood, but in trials their health effects have been mixed and often absent. In a 2026 trial of 410 people with early Parkinson disease, symptom scores worsened on NR but not placebo.
- A 2026 systematic review found no trial testing IV NAD+ for aging or wellness. In one wellness clinic’s records, all 6 people given IV NAD+ had moderate to severe symptoms, such as cramps and chest pressure, during infusions.
- NAD+ is not FDA-approved. In 2019 the FDA proposed leaving it off the 503A bulks list of extra compounding ingredients. Until it decides, it does not intend to act against state-licensed pharmacies compounding with it under set conditions.
- NMN and NR are sold as dietary supplements, which the FDA does not approve before sale. In September 2025 the FDA reversed its 2022 position that NMN could not be sold as a supplement.

## At a glance

| Compound | Kind | How it is taken | FDA status | Research in people |
| --- | --- | --- | --- | --- |
| NAD+ (nicotinamide adenine dinucleotide) (also: NAD, nadide, coenzyme I, beta-NAD) | Coenzyme built from two nucleotides (not a peptide) | Infusion into a vein; injection under the skin or into a muscle; nasal spray | Not FDA-approved; in 2019 the FDA proposed not to add NAD to the 503A bulks list of extra compounding ingredients, but while NAD stays under evaluation (Category 1), the FDA does not intend to act against state-licensed pharmacies compounding it under set conditions. (checked 2026-11-13) | Small trials in people. Two randomized trials by one hospital team in China gave 180 and 120 heart patients low-dose NAD+ by vein for 7 days; heart pumping was better than with placebo at one month, major events did not clearly differ, and neither tested aging or wellness. |
| NMN (nicotinamide mononucleotide) (also: beta-nicotinamide mononucleotide, MIB-626) | NAD+ precursor, itself a nucleotide (not a peptide) | Taken by mouth | Not FDA-approved as a drug; in September 2025 the FDA reversed its 2022 position and said NMN is not excluded from the definition of a dietary supplement, though it remains a new dietary ingredient. (checked 2026-11-13) | Small trials in people. A 2026 meta-analysis of 15 randomized trials, lasting 14 days to 24 weeks, found no effect on weight, blood sugar or cholesterol and no rise in side effects. Trials do show NMN raises blood NAD+. |
| NR (nicotinamide riboside) (also: nicotinamide riboside chloride) | NAD+ precursor and a source of vitamin B3 (not a peptide) | Taken by mouth; also given by infusion into a vein | Not FDA-approved as a drug but sold as a dietary supplement; it is neither on the 503A bulks list of extra compounding ingredients nor being evaluated for that list, though for outsourcing facilities NR chloride is under evaluation (Category 1). (checked 2026-11-13) | Small trials in people. A 2026 randomized trial of 410 people with early Parkinson disease, lasting 52 weeks, found no benefit and worse symptom scores than placebo; smaller trials show NR raises blood NAD+ with few health changes. |

## What they are

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme: a helper molecule that many enzymes need to work. Every living cell uses it to turn food into energy. NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are smaller molecules that the body turns into NAD+, so they are called NAD+ precursors. NR is also a source of vitamin B3. [1, 2, 3, 4]

None of the three is a peptide. Peptides are chains of amino acids. NAD+ is built from two nucleotides, the kind of building block that also makes up DNA and RNA. One nucleotide carries adenine and the other carries nicotinamide, a form of vitamin B3. NMN is the nicotinamide half on its own. NR is NMN without its phosphate group. [1, 3, 5, 6]

## How they work

NAD+ carries electrons in the chemical reactions that release energy from food. It is also used up by enzymes: PARPs consume it while repairing damaged DNA, and sirtuins, a family of enzymes studied in aging research, depend on it. Another enzyme, CD38, breaks it down. [1, 3, 7]

Cells build NAD+ from tryptophan, an amino acid in dietary protein, and from vitamin B3, also called niacin, which includes nicotinic acid and nicotinamide. They also recycle nicotinamide, the piece left over when enzymes use NAD+. NR and NMN feed into this recycling route: NR becomes NMN, and NMN becomes NAD+. A diet lacking niacin leaves cells short of NAD+ and causes pellagra, a disease of the skin, gut and brain. [3, 6]

In a 2026 study, 67 healthy adults were randomly assigned to NR, NMN, nicotinamide or a placebo for 14 days. NR and NMN raised blood NAD+ to a similar degree; nicotinamide did not. Lab experiments in the same study showed that gut bacteria can turn NR and NMN into nicotinic acid, which the authors proposed is how they raise blood NAD+. [8]

In a 2019 study, 8 healthy men received NAD+ into a vein over six hours and 3 received salt water. For the first two hours, NAD+ in the blood did not rise. The researchers concluded that, as fast as it arrived, the infused NAD+ was being taken up by tissues, broken down or both. Blood levels were higher by the end of the infusion. A company whose director was medical director of a clinic offering NAD+ infusions helped fund the study. [9]

## Why NAD+ is linked to aging

In rodents, NAD+ levels fall in many tissues with age. A 2016 study found that 12 months of NMN by mouth blunted several age-related changes in mice, including weight gain and falling insulin sensitivity (how well the body responds to insulin). Another 2016 study reported that NR, even when started late in life, slightly lengthened mouse lifespan. But when the National Institute on Aging’s Interventions Testing Program fed NR to genetically varied mice at three sites from 8 months of age, it did not affect their lifespan. [3, 10, 11, 12]

In people, a 2015 brain-scan study of 17 healthy volunteers and a 2012 study of skin from 49 people found lower NAD+ at older ages. Two 2026 studies of whole blood found no fall with age: one measured NAD+ in seven groups of people, and the other measured all forms of NAD in 1,068 adults. [2, 7, 13, 14]

## How they are taken

NAD+ is given as an infusion into a vein (an intravenous, or IV, drip) or as an injection under the skin or into a muscle. It has also been sold as a nasal spray and as tablets that dissolve under the tongue. NMN and NR are taken by mouth as dietary supplements. NR has also been given by IV. [5, 15, 16, 17, 18, 19, 20]

## What the research in people shows

A 2026 systematic review, which gathers all studies that meet set criteria, found 33 studies published from 2010 through October 2025 that gave NAD+ or related compounds to people. Of these, 28 were randomized. Swallowed NR and NMN consistently raised NAD+ and related molecules in blood or blood cells. Their effects on physical function, metabolism and blood vessels were mixed and often absent. [19]

NOPARK, a 2026 trial, randomly assigned 410 people with early Parkinson disease, at 11 centers in Norway, to NR or a placebo for 52 weeks. Symptom scores worsened in the NR group and stayed about the same in the placebo group. The difference was unlikely to be due to chance, but it was smaller than the change the researchers counted as large enough to matter to patients. Of five main secondary measures, only a scale of nonmotor symptoms (Parkinson symptoms other than movement problems) differed: it also worsened more with NR. [21]

In a 2018 trial of 40 men with obesity, 12 weeks of NR did not improve insulin sensitivity or body composition. In a 2026 pilot trial, 52 older adults with mild memory problems were randomly assigned to NR or placebo for 12 weeks, and 42 finished. NR raised blood NAD+ but did not improve thinking or memory. [22, 23]

One positive result came from the NICE trial in peripheral artery disease (narrowed arteries in the legs). It split 90 people among NR alone, NR with resveratrol, and placebo. After six months, people taking NR alone did better on a six-minute walking test than those on placebo; NR with resveratrol made no clear difference. The NR result met a looser statistical standard than most trials use, set in advance, and the authors called for a larger trial. [24]

In a 2021 trial, 25 postmenopausal women with prediabetes and overweight or obesity took NMN or a placebo for 10 weeks. Insulin sensitivity in muscle rose with NMN but not with placebo; body composition, blood pressure, blood sugar and blood fats did not change in either group. A 2026 meta-analysis pooled 15 randomized NMN trials lasting 14 days to 24 weeks. It found no effect on body weight, blood sugar or cholesterol, and a slight fall in diastolic blood pressure (the lower number). [25, 26]

A 2025 meta-analysis of 10 randomized trials in older adults found that the evidence does not support NMN or NR for preserving muscle mass and function. [27]

Two randomized trials by one hospital team in China gave NAD+ by vein for 7 days alongside standard heart care. One enrolled 180 people with heart failure caused by poor blood flow to the heart muscle; the other enrolled 120 people treated for a severe type of heart attack. In both, heart pumping (ejection fraction) was better at one month with NAD+ than with placebo. Major heart and stroke events over six months did not clearly differ. [28, 29]

Those hospital trials used a small fraction of the NAD+ given in the wellness infusions studied in 2019 and 2026, so they say little about wellness drips. The 2026 systematic review found no trial testing NAD+ given into a vein or a muscle for aging or wellness. [9, 15, 19, 28, 29]

## Side effects and risks

None of the three has an FDA-approved label listing its risks; what is known comes from studies and FDA reports. A 2026 review of records from a commercial wellness clinic found that all 6 people given IV NAD+ had moderate to severe symptoms during infusions. They included stomach cramps, diarrhea, nausea, vomiting, a faster heartbeat and chest pressure. The symptoms stopped when each infusion ended. Five of the 8 people given IV NR had milder symptoms, such as tingling in the tongue, jaw or arms. [15]

At the clinic, symptoms led people given NAD+ to slow their infusions, which took longer than the NR infusions. In the 2019 study, no adverse events (unwanted medical problems of any cause) were recorded among the 8 men given NAD+ over six hours. Neither study tested whether a slower infusion prevents symptoms. The clinic company employed the 2026 authors and paid for their study, and a company that makes NR donated the NR. [9, 15]

A January 2026 FDA warning letter to an outsourcing facility (a compounder registered with the FDA under section 503B) described three patients. They developed low blood pressure, uncontrollable shaking, shivering and body aches during or soon after receiving the facility’s compounded NAD+ from one vial, and were directed to an emergency room. An unopened vial from the same batch contained high levels of bacterial endotoxins, toxic fragments of bacteria. The FDA has also noted that NAD+ breaks down when exposed to light, moisture, alkaline conditions or room temperature. [18, 30]

The 2026 systematic review found swallowed NR and NMN generally well tolerated over weeks to months. The 2026 NMN meta-analysis found no increase in side effects, serious side effects or liver enzymes. [19, 26]

For swallowed NR, NOPARK’s worse Parkinson scores are the main warning sign. Serious adverse events, such as those needing a hospital stay, did not happen more often with NR (17 of 205 people) than with placebo (29 of 205). [21]

## FDA status

NAD+ is not FDA-approved for any use. In February 2026 the FDA called NAD+ repackaged by one company an unapproved new drug: a drug sold without the FDA approval the law requires. In 2019 the FDA told an online seller that claims to treat diseases such as Parkinson disease and diabetes made its NAD+ and NMN products drugs that needed FDA approval. [16, 31, 32]

NAD+ is not on the 503A bulks list, the FDA’s list of extra ingredients that state-licensed pharmacies may compound with under section 503A. But the FDA’s May 2026 list of nominated substances puts NAD in Category 1, under evaluation. Until the FDA decides, it does not intend to act against pharmacies compounding with Category 1 substances under set conditions. One salt form, beta-NAD disodium salt trihydrate, is in Category 3, for substances nominated without enough information for the FDA to evaluate them. The policy does not cover it. [30, 33, 34, 35]

In 2017 the FDA’s Pharmacy Compounding Advisory Committee voted against adding NAD to the 503A bulks list, after the FDA reviewed it for fatigue in multiple sclerosis. In September 2019 the FDA proposed not to add it, citing its instability, too little safety data and no published studies supporting that use. As of November 2026 the proposal had not been finalized, and the list had not changed since 2019. [30, 34, 35]

Outsourcing facilities follow a separate federal list, and NAD+ is not on it. The FDA’s March 2025 list of substances nominated for these facilities puts beta-NAD in Category 1, under evaluation. But in its January 2026 warning letter, the FDA said one facility’s NAD+ products were not eligible for the compounding exemptions or for that review policy. [18, 32]

NMN and NR are sold as dietary supplements, which the FDA does not approve before sale. The FDA says supplements must be swallowed, so NR given by IV is not one. A new dietary ingredient is one not sold in the United States before October 15, 1994. Its maker or distributor generally must send the FDA safety evidence at least 75 days before selling it. [36]

In late 2022 the FDA told companies that had notified it about NMN that it could not be sold as a supplement. The reason: NMN had not been lawfully marketed as a supplement before it was authorized for study as a drug. In September 2025, answering a 2023 citizen petition, the FDA reversed itself. It said earlier sales no longer had to be lawful to count, and NMN had been sold as a supplement in the United States by 2017, before the drug authorization. The decision addressed NMN’s legal status, not its safety, and NMN remains a new dietary ingredient. [5]

Companies have filed new dietary ingredient notifications for NR since 2015. In 2016 the FDA had no questions about one company’s conclusion that NR is generally recognized as safe (GRAS) as a vitamin B3 source in certain foods and drinks. It made no GRAS finding of its own. [4, 17]

For state-licensed pharmacies, neither NMN nor NR is on the 503A bulks list or in any category of the FDA’s May 2026 list of nominated substances. So the Category 1 policy does not cover them. For outsourcing facilities, the FDA’s March 2025 list puts NR chloride in Category 1 and does not include NMN. [32, 33, 34, 35]

## Rules in sport

The World Anti-Doping Agency bans IV infusions or injections totaling more than 100 milliliters in 12 hours, at all times. Those received during hospital treatment, surgery or medical tests are exempt. Outside those settings, an athlete needs an approved therapeutic use exemption: permission to use a banned method for a medical reason. The rule is unchanged in the 2027 list. [37, 38, 39]

## What isn’t known

No trial has shown that NAD+, NMN or NR slows aging or extends life in people. The 2026 systematic review called the evidence that they help with aging or wellness inconclusive. In people, apart from a slight fall in diastolic blood pressure in the 2026 NMN meta-analysis, the positive health results described here come from four trials of 25 to 180 participants. Each measured a narrow outcome, such as walking distance or heart pumping. [19, 24, 25, 26, 28, 29]

The longest trials described here gave NR for a year and NMN for 24 weeks, so the safety of taking them for years is unknown. It is also unknown why NR was linked to worse Parkinson symptoms in NOPARK, or whether similar effects occur in other conditions. [21, 26]

The effects of repeated IV infusions over months or years are unknown. A registered trial comparing NAD+ and NR injected under the skin, into muscle and into a vein began in 2024; its record, last updated in April 2025, shows no results. A 2026 study tested nasal NAD+ in mice with a damaged sense of smell and in human cells grown in a dish, but not in people. [19, 20, 40]

Two 2023 animal studies point in opposite directions on cancer. In one, NR given to animals increased the spread of triple-negative breast cancer, an aggressive type, to the brain. In the other, NR slowed the growth and spread of liver cancer in mice. Neither shows what happens in people. [41, 42]

What a blood NAD+ test means is unclear. In the 2026 study of seven groups, blood NAD+ stayed stable with age and lifestyle changes, and its authors questioned it as a marker of aging. [13]

## Questions to ask a clinician

- What would NAD+, NMN or NR be meant to do for me, and how would we know if it worked?
- Is there an FDA-approved treatment with stronger evidence for my concern?
- Who would make any injected or infused NAD+, and how is each batch tested for sterility and endotoxins?
- During an infusion, who would watch for symptoms such as chest pressure?
- Could NR or NMN affect my medicines or a condition I have, such as Parkinson disease or a past cancer?
- If I compete in a tested sport, would an IV infusion need a therapeutic use exemption?

Sources for the list above: [37, 39]

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