NAD+ side effects

Common during IV infusion

These findings come from small studies of NAD+ given into a vein.

• Gut, heart rate and chest symptoms (6 of 6 people). A 2026 retrospective review of a US wellness clinic's records looked at clients given 500 mg of NAD+ by IV once a day for 4 days. Every one of them had moderate to severe symptoms during infusion: abdominal cramping, diarrhea, nausea, vomiting, a faster heart rate, throat pain, congestion and chest pressure. All of it stopped as soon as the infusion was complete.¹
• Slowed drips. Clients set their own drip rate. Symptoms stretched NAD+ infusions to an average of about 97 minutes, against 37 minutes for the same 500 mg of nicotinamide riboside (NR).¹
• Also reported in practice (frequency unknown). The same authors list nausea, malaise, sweating, stomach cramping and headache as side effects that clinicians and patients commonly report with NAD+, citing earlier work. They give no counts.¹
• Suggested cause. The authors write that these side effects are likely driven by very high NAD+ levels outside cells and their inflammatory effects. Their study did not test this.¹
• None at a slow rate (0 of 8 people). In a 2019 randomized pilot, 750 mg infused across 6 hours (roughly 2 mg a minute) caused no adverse events in 8 healthy men.²

Side effects by injection route

A 2026 preprint compared NAD+ with NR at 100 mg, given three ways to groups of 4 to 6 adults. The authors call these after-the-fact comparisons suggestive:⁹

The authors reported no attributable unexpected adverse events. The paper has not been through journal review, and its first trial was funded by ChromaDex.⁹ Counts for each route were not available for this page.

Serious reactions linked to contamination

FDA has described serious reactions after NAD+ injections as consistent with contamination:

• FDA notice, October 2024. FDA received adverse event reports after NAD+ injectable drugs, including severe chills, shaking, vomiting and fatigue, some needing medical treatment.³ It said the reactions fit excessive endotoxins (toxins from bacteria), and that some compounders had made IV products from food-grade NAD+ supplied by repackagers.³
• Emergency room referrals, January 2026 warning letter. Three patients had low blood pressure, uncontrollable shaking, shivers and body aches during or shortly after a compounded NAD+ product. They were directed to the emergency room.⁷ An unopened vial from the same lot held 3,360 EU/mL of bacterial endotoxins.⁷
• Class I recall. FDA classified the firm's recall of that same lot of NAD+ for Injection as Class I on October 21, 2025, for elevated endotoxin levels. It covered 100 mg/mL and 200 mg/mL strengths in 10 mL vials.¹⁰
• Recall history. Between 2017 and 2025, FDA classified 14 recalls of NAD or NADH products, mostly because sterility could not be assured.¹¹

What lab tests showed

In the 2026 clinic review, liver enzymes stayed stable or fell 30 days after infusion with either NAD+ or NR. Levels of hsCRP (high-sensitivity C-reactive protein) were unchanged.¹ The same clinic funded the study.¹

Oral precursors, for comparison

Precursors taken by mouth have been followed for longer, though they are different compounds from injected NAD+:

• Nicotinamide riboside at up to 1,000 mg a day for 8 weeks: adverse events did not differ significantly from placebo in 140 adults.¹²
• In 40 obese men, 12 weeks of nicotinamide riboside at 2,000 mg a day appeared safe.¹³
• Nicotinamide mononucleotide for 60 days: no safety issues were found in 80 adults, in a trial fully funded by two companies.¹⁴

Reading these reports

Two kinds of reaction appear in the record, and they differ. Symptoms during the drip, such as cramping, nausea and chest pressure, came from routine clinic infusions of a pharmacy-made product and ended when the drip stopped.¹ The severe chills and shaking in FDA's 2024 reports are, in FDA's words, consistent with excessive endotoxins,³ and the low blood pressure and shaking in the 2026 warning letter came from a compounded lot later found to hold excess endotoxins.⁷ The data behind both are thin. The clinic study was retrospective, with 6 people on NAD+ who controlled their own drip rate.¹ A registered randomized trial (NCT06382688) planned to measure how long people take to receive an IV NAD+ drip comfortably, but its registry record shows no results.⁶

Warnings and unknowns

• Too little safety data. In 2019, FDA found the nonclinical data inadequate to describe NAD's possible toxicity. Nor did it find enough clinical data to assess NAD's safety in compounded drugs.⁸
• Long-term effects. A 2021 review states it is still unknown whether long-term use of NAD+ precursors has side effects.⁴ A 2020 review of 147 studies, 113 of them preclinical, names potential risks of raising NAD+ with precursors: build-up of toxic metabolites, tumor growth and cell senescence.¹⁵
• Untested groups. A registered IV trial excluded pregnancy, breastfeeding and several chronic diseases, so it offers no data on those groups.⁶
• Product quality. FDA tied the serious cases above to endotoxins: its 2024 notice warned compounders about food-grade NAD+, and the 2026 letter concerned a compounded lot.³⁷ No endotoxin or sterility data were found for research-grade vials.
• Athletes. Under the 2026 WADA list, more than 100 mL of IV infusions or injections in 12 hours is banned unless received during hospital treatment, surgery or clinical diagnostic investigations.¹⁶

Related pages: What is NAD+?, NAD+ benefits and uses, NAD+ dosage and How to reconstitute NAD+.