For research and educational use. PepCaddie does not sell peptides and recommends no doses.
Plain reference

NAD+ guide

This NAD+ guide has to separate four things that get sold as one. NAD+ itself given by drip or injection; nicotinamide riboside taken by mouth; NMN taken by mouth; and plain vitamin B3. They have four different evidence bases and results do not transfer between them169. The short version: the oral trials work biochemically and fail clinically, and the drip has almost no evidence at all.

The short answer

  • Is an NAD+ drip an approved medicine? No. Every one sold in a US clinic is a compounded or unapproved preparation124.
  • Evidence for the drip: a 2026 systematic review found no outcomes trial of intravenous or intramuscular NAD+ for anti-ageing or wellness at all9.
  • Does the infused NAD+ reach your cells? Nobody has measured it. The one human study found it vanished from blood and some left in the urine unchanged815.
  • Oral precursors: reliably raise blood NAD+, reliably fail on their own endpoints171820219.
  • The documented hazard: FDA reports endotoxin reactions from food-grade NAD+ used to make injections23.
  • For tested athletes: the rule is about the drip, not the drug — over 100 mL in 12 hours is a prohibited method7.

The one study of what an infusion actually does

There is exactly one published human pharmacokinetic study of infused NAD+: eight men, 750 mg over six hours. The result surprised its own authors. Nothing changed in the blood for the first two hours — the infused NAD+ was rapidly and completely removed from plasma. By six hours, NAD+ and one of its breakdown products were turning up in the urine, meaning part of the dose left the body unchanged815.

The authors read that pattern as the molecule being cleaved by enzymes in the blood before it ever reaches a cell. It is a large molecule being asked to cross a cell membrane, which is not something it does easily.

And here is the gap that matters most: no human study has ever measured NAD+ inside any tissue after an NAD+ infusion8. Not muscle, not brain, not liver. The entire premise — that a drip raises your cellular NAD+ — has never been tested in a person. One trial was designed to compare blood NAD+ after an NAD+ drip against the alternatives. It enrolled 53 people, has a primary completion date in March 2024, and has never reported anything.

What the drip feels like, and why that matters

The best published description comes from a clinic chart review of six people. They reported moderate to severe stomach symptoms, a faster heart rate and chest pressure during their infusions. The symptoms stopped when the infusion did — but they were bad enough that the drip had to be slowed. NAD+ infusions averaged 97 minutes against 37 minutes for the comparison arm10.

That is the infusion-rate phenomenon clinics manage routinely, and it is a pharmacological effect rather than a contamination problem. It is worth separating from the other hazard below, because they have different causes and different fixes.

The hazard FDA has actually documented

In October 2024 FDA published a notice stating it was aware of compounders using food-grade NAD+ bought from repackagers to make intravenous products2. Food-grade material is not suitable for sterile drugs without proper processing, because of contamination with microbes and endotoxins. FDA then reported receiving adverse event reports after NAD+ injections — severe chills, shaking, vomiting and fatigue, some requiring medical treatment — and said these were consistent with excessive endotoxin23.

A January 2026 warning letter shows what that looks like. Three patients given NAD+ from the same vial developed low blood pressure, uncontrollable shaking, shivers and body aches, and were sent to the emergency room. No finished-product testing had been done before release. An unopened vial from the same lot was later found to contain 3,360 endotoxin units per millilitre.

FDA also recorded that the firm had submitted no adverse event reports and had no documented procedure for doing so3. That is a structural reason to assume the safety picture is more incomplete than it looks, rather than reassuringly quiet.

The two controlled trials of injected NAD+, and their doses

Only two exist. A 180-person trial in heart failure gave 10 mg a day into a vein for seven days; at one month the treated group had a higher ejection fraction, 45.4 against 42.4 per cent. That was the only measure to reach significance — serious cardiac events, hospital admissions, symptom class and the blood marker of heart strain all fell short11. A 38-person trial in sudden hearing loss gave 5 mg a day into muscle and reported clearly better recovery, though its control group got no sham injection, so everyone could tell who was being treated12.

Now the number that reframes both: 5 to 10 mg a day. A wellness-clinic drip is typically 250 to 1200 mg. These trials used somewhere between a twenty-fifth and a hundredth of that dose1112. Whatever they show, they are not evidence about the thing being sold.

Addiction: the biggest claim, the thinnest evidence

NAD+ drips are marketed hard for addiction and withdrawal. Registered trials of intravenous or subcutaneous NAD+ for substance use disorder, alcohol use disorder or detoxification: zero13.

The published basis is two papers from one group reporting the identical p-values on the identical fifty patients — two write-ups of one dataset. Both are uncontrolled, unblinded, and use self-reported scores collected by a counsellor from people simultaneously enrolled in a dependency treatment programme. And the infusion was NAD+ combined with amino acids and a vitamin mixture, so nothing observed can be attributed to NAD+ at all13.

The oral evidence, which is real and mostly negative

This is where the actual science is, and it deserves a fair hearing. Around thirty randomised trials of nicotinamide riboside and fifteen of NMN exist. They reliably show one thing: taking these by mouth raises blood NAD+, often two to five fold. That is genuine target engagement.

What happens next is the problem. The cleanest test is a long-COVID trial: 2000 mg a day for 24 weeks raised blood NAD+ two and a half to three times, and then found no difference from placebo in cognition on any of three measures, nor in fatigue, sleep, anxiety or depression21. A 12-week trial using a proper insulin clamp found nothing. Six months of NMN in older adults with diabetes did not improve grip strength or walking speed171820219.

The most-cited positive result, an NMN trial in prediabetic women, rests on comparing each group against itself rather than against the other — which is not the test that establishes an effect — and its analysis is disputed in print by a technical comment in the same journal19.

Something else worth knowing: industry entanglement is the norm here rather than the exception, across the infusion study, the tolerability study and most of the oral trials8101716. That is disclosed rather than hidden, and it is a reason to read framing carefully rather than to throw out the data.

Where the enthusiasm comes from

Eighty rodent studies, and many of them found real benefit: metabolic, mitochondrial, inflammatory and functional9. That is a substantial body of work and it is why serious people are interested.

The only formal safety package for injected NAD+ is also in animals. In dogs, 3 mg/kg was the safe dose; at 10 and 30 mg/kg heart rate rose, two intervals in the heart tracing shortened and blood pressure fell22. Repeated injection into muscle in rats caused injection-site and nerve lesions that reversed. That package was designed for a 5 to 100 mg human product, not for gram-scale drips.

The longest published human exposure to injected NAD+ is about two weeks. There is no chronic safety study, no registry and no surveillance system for compounded NAD+2220.

Two regulatory points worth having right

NMN's status reversed. In 2022 FDA said NMN could not be sold as a dietary supplement, because it had been authorised for investigation as a new drug first. On 29 September 2025 FDA reversed that: NMN had in fact been marketed as a supplement since 2017, before that authorisation. FDA explained its own error — the drug it found under a code name was not recognised as being NMN — and formally set the 2022 letters aside in December 20256. Anything still saying FDA has banned NMN is describing a position FDA abandoned.

In sport, the rule is about the bag. NAD+, NMN, riboside and niacin are not named anywhere on the prohibited list. That is not the relevant rule. Any intravenous infusion totalling more than 100 mL in a 12-hour period is a prohibited method at all times, with only three exceptions — hospital treatment, surgery, diagnostic investigation7. A wellness drip is none of those, and a typical one is 250 to 1000 mL.

Where the rest of the detail lives

The interactive library on the homepage carries the fuller reference entry for NAD+, including the amounts and handling notes it holds for every compound. That is general reference information, the same for every visitor.

Open the full NAD+ reference in the library

References

These are the sources behind this page, listed so you can read them yourself rather than take our word for it. Animal and laboratory findings do not establish that something works or is safe in people. Doses and protocols shown on a study card are that study's research parameters, not recommendations. PepCaddie does not sell peptides and does not choose a dose for anyone; this is educational material and it does not replace a qualified healthcare professional.

  • The only study of what an infusion actually does

    2019

    Human observational study

    Healthy adult men750 mg over 6 hours by drip studiedA single infusion, sampled to 8 hoursBlood and urine NAD+

    The dose above is the amount used in this study. It is research information, not a recommended dose, and PepCaddie does not convert study doses into human doses.

    The finding was not what anyone expected. Nothing changed in the blood for the first two hours: the infused NAD+ was rapidly and completely removed from plasma. By six hours, NAD+ and one of its breakdown products were appearing in the urine, meaning part of the dose left the body unchanged. The authors read the pattern as the peptide being cleaved by enzymes in the blood before it reaches cells. No adverse events occurred at this deliberately slow rate.

    Limitation: Eight men in the active arm, measuring blood and urine only. No tissue was sampled, so the study cannot say whether any infused NAD+ reached a cell anywhere. It was funded by a company that sells the therapy and run at a clinic that provides it, which the authors disclose.

    Open pilot with a small saline comparison group, not blindedView study: The only study of what an infusion actually does

  • The systematic review, and its one decisive sentence

    2026

    Systematic review

    Humans and rodentsAnti-ageing and wellness outcomes

    The review states the position plainly: no eligible outcomes trial evaluated intravenous or intramuscular NAD+ itself for anti-ageing or wellness indications. What it did find was that oral nicotinamide riboside and NMN consistently hit their biochemical target and were well tolerated, while their effects on the outcomes that would matter to a person were heterogeneous and often null. The rodent literature, 80 studies of it, frequently showed benefit.

    Limitation: A review can only summarise what exists. Its author discloses owning a services company for an aesthetics clinic, noting that the clinic does not offer NAD+ infusions.

    Systematic review of 113 studiesView study: The systematic review, and its one decisive sentence

  • What the drip actually feels like

    2026

    Human observational study

    Adults attending a commercial wellness clinic500 mg by drip on 4 consecutive days studied30 days of follow-upTolerability

    The dose above is the amount used in this study. It is research information, not a recommended dose, and PepCaddie does not convert study doses into human doses.

    The people given NAD+ reported moderate to severe stomach symptoms, a faster heart rate and chest pressure during their infusions. Symptoms resolved when the infusion finished, but they were bad enough that the drip had to be slowed: NAD+ infusions averaged 97 minutes against 37 minutes for the comparison. This is the clearest published description of the infusion-rate problem that clinics manage by slowing the drip.

    Limitation: Six people in the NAD+ group, reviewed after the fact, with no randomisation and no control. The blood-test changes it reports are many comparisons on tiny groups and should be read as noise. Every author was employed by the wellness chain whose clients were reviewed.

    Retrospective review of clinic records, no control groupView study: What the drip actually feels like