NAD+ is sold as an infusion, an injection and a nasal spray through the same clinics and vendors as research peptides, which is why its side effects are searched here. It is not a peptide — nicotinamide adenine dinucleotide is a coenzyme built from two nucleotides — and no NAD+ injection has an FDA-approved label, so there is no regulator-reviewed list of its side effects to quote. This page sets out what the published studies and FDA's records do contain, with dates, and what they cannot tell you. It reports; it recommends nothing, and where a decision is involved the person to make it with is a clinician. The dose figures behind this record, from 5 mg to 750 mg, are on our NAD+ dosage page. How brands appear on this site is set out on our disclosure page.
Two infusion studies, two different answers
Only two published studies report what people experienced while NAD+ was going into a vein, and they point in opposite directions.
| Grant et al. 2019 | Reyna et al. 2026 | |
|---|---|---|
| Setting | Research study, randomised against saline | Retrospective review of a wellness clinic's records |
| People given NAD+ | 8 healthy men, aged 30–55 | 6 clinic clients |
| Dose | 750 mg in saline over 6 hours, once | 500 mg in 500 mL saline, four consecutive days |
| Rate | about 2 mg a minute, fixed | about 5 mg a minute on average (our arithmetic), slowed as needed |
| What was recorded | "No adverse events were observed during the 6 h infusion" | Every client: moderate to severe abdominal cramping, diarrhoea, nausea, vomiting, raised heart rate, throat pain, congestion, chest pressure |
| After the infusion | Liver enzymes unchanged or lower | Symptoms "ceased immediately upon infusion completion"; nothing further reported to 30 days |
| Source | PMC6751327 | PMC12907335 |
The clinic study compared NAD+ with nicotinamide riboside, a precursor, given the same way: eight clients on nicotinamide riboside had only minor tongue, jaw and arm tingling and mild cramping, and their infusions averaged 37 minutes against 97 for NAD+ — the NAD+ drips took longer because symptoms led to them being slowed. The authors cite a preprinted randomised trial reporting the same pattern.
The rates are the thread between the two studies, and the calculation is ours rather than either paper's: 750 mg over 360 minutes is about 2.1 mg a minute; 500 mg over an average 97 minutes is about 5.2 mg a minute. The study that recorded no symptoms ran at well under half the speed of the one where everyone had them. Two small studies cannot establish that speed is the cause — they differ in setting, people and design too — but it is the variable the clinic itself adjusted, and it is the one a reader can ask about.
One discrepancy to flag for anyone checking: Grant's methods state 750 mg, while the stated rate of 3 µmol a minute for six hours works out to about 716 mg at NAD+'s molecular weight — the figure our dosage page uses. Either way the rate is about 2 mg a minute.
Both studies carry limits worth stating. Reyna and colleagues' review had six NAD+ patients, no placebo, and all seven authors were employed by the clinic company (Restore Hyperwellness), as the paper's conflict-of-interest statement says. Grant and colleagues' author list includes NAD+ Research Inc. and a wellness centre. Neither measured anything beyond 30 days.
Everything else in the published record
- A randomised trial at a much lower dose. Yu and colleagues gave 10 mg intravenously for seven days to 180 people with heart failure (2026); it is on our dosage page for its results. At one-fiftieth of the clinic dose, it says little about a 500 mg drip.
- A single case report (ACR Open Rheumatology, 2026): a woman given four 250 mg infusions over about an hour each, every two weeks, with "no infusion-related adverse events".
- A 2026 systematic review of NAD+ supplementation found no outcome trial of intravenous or intramuscular NAD+ for anti-ageing or wellness among 33 human intervention studies (PubMed 41655607); the Grant study was counted as context only.
Nothing published tests NAD+ injected under the skin or into muscle. A US registration comparing 100 mg of NAD+ by intramuscular, subcutaneous or IV push with nicotinamide riboside (NCT06919328) had posted no results on 2026-09-25.
What FDA's adverse-event database holds
We queried FDA's adverse-event database on 2026-09-25 for NAD+ under every name it is filed as — NAD, NAD+, nadide, nicotinamide adenine dinucleotide — and excluded the related supplements nicotinamide riboside and NADH. It returned 72 reports, most of them recent:
| Reports | |
|---|---|
| Naming NAD+ in any role | 72 |
| Received in 2025 or 2026 | 49 |
| NAD+ coded as a suspect product | 19 |
| Suspect, and a single compounded injection with tirzepatide or semaglutide | 6 |
| Suspect, and recording a death | 1 (that combined product among twenty drugs) |
Most of the 72 name NAD+ as one of many supplements someone was taking, often by mouth, and say nothing about it. The 19 where it is a suspect product are the ones to read, and three patterns run through them:
- Infusion reactions. One report names NAD+ as the only product, with "product contamination", "infusion related reaction", raised liver enzymes and a flu-like illness; another codes lethargy, disorientation, nausea and an infusion reaction.
- NAD+ compounded into GLP-1 injections. Six reports describe a single product combining NAD+ with tirzepatide or semaglutide and vitamin B12 — a combination no approved product contains and no study has tested. Their coded terms include hives, lip and facial swelling, throat tightness and shortness of breath in one, low blood pressure in another, and "product compounding quality issue" and "product formulation issue" in two. How compounded GLP-1 products are regulated is on our 503A vs 503B page, and the approved products' own figures are on our tirzepatide dosage page.
- Research-market stacks. In 2026 NAD+ appears as a suspect alongside retatrutide, which has no approval anywhere, in two reports, with bacteriostatic water listed in one.
None of these reports establishes cause, and FDA does not require that it be shown. The database also only holds what someone files: clinics and compounders are not obliged to report, and our peptide side effects page explains why a small count is not a clean record.
What FDA found in a compounder's vials
The most specific regulatory record on injected NAD+ is not about NAD+ at all but about what else can be in the vial. FDA's warning letter to GenoGenix LLC, an outsourcing facility in Boca Raton, dated 2026-01-20, records that three patients developed low blood pressure, uncontrollable shaking, shivers and body aches during or shortly after receiving NAD+ from one lot and were directed to the emergency room; an unopened vial from that lot contained bacterial endotoxins at 3,360 EU/mL; and no finished-product testing had been done before release. The letter also states that NAD+ is not on the 503B bulks list. Endotoxin — fragments of bacterial cell walls — produces fever, chills and falling blood pressure, which is why a sterility and endotoxin result matters more than a purity figure for anything injected; our peptide testing page sets out what each test does and does not show. The facility is on our FDA warning-letter tracker.
What the record does not contain
A labelled list of NAD+ injection side effects, because no product has been approved; any controlled study of subcutaneous or intramuscular NAD+; any study longer than 30 days; any comparison of infusion rates designed to find a tolerable one; any study of NAD+ combined with a GLP-1 drug; and any account of whether injected NAD+ reaches cells intact, which the one pharmacokinetic study could not show. Its companion on the same drip menu, glutathione, is a genuine peptide with a different record, set out on our glutathione dosage page; Peptide Lexicon's NAD entry explains the molecule for beginners. Anyone considering an NAD+ injection, or wondering whether a symptom is related to one, should take the question to a clinician who can see their history.
Sources and dates
Read 2026-09-25: Reyna et al., Frontiers in Aging 2026 (PMID 41704678, full text PMC12907335), methods, results and conflict-of-interest statement; Grant et al., Frontiers in Aging Neuroscience 2019 (PMID 31572171, full text PMC6751327), methods and safety results; the abstracts of Yu et al. 2026 (PMID 40954388), Gallagher and Emmanuel 2026 (PMID 41655607) and the 2026 ACR Open Rheumatology case report (PMID 42751848); FAERS via the openFDA drug event endpoint (NAD, NAD+, nadide and nicotinamide adenine dinucleotide; 72 reports, each read for suspect coding, product and reactions); FDA's warning letter to GenoGenix LLC (reference 718739, 2026-01-20); ClinicalTrials.gov record NCT06919328. The infusion rates are our arithmetic from each paper's stated dose and time. Corrections go to the contact page.