NAD+
Nicotinamide adenine dinucleotide
TL;DR
NAD+ is a coenzyme every cell uses for energy metabolism and DNA repair. Oral precursors (NR, NMN) reliably raise blood NAD+, but no trial of NAD+ itself, oral or IV, has shown a health benefit yet.
Ideal For
- Adults curious about NAD+ who accept unproven benefits
- Research participants in NAD+ trials
- People choosing between precursors and drips
Avoid If
- You are pregnant or breastfeeding
- You have heart disease and are considering IV NAD+
- You expect it to treat a diagnosed condition
- You are a child or teenager
Frequently Asked Questions
What does NAD+ do in the body?
Do NAD+ supplements actually work?
Are NAD+ IV drips worth it?
Is NAD+ or NMN better?
What are the side effects of NAD+?
Does NAD+ decline with age?
Overview
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell. It carries electrons in energy metabolism and is the fuel for enzymes that repair DNA (PARPs) and regulate genes (sirtuins). Levels appear to fall with age: in 49 human skin samples, NAD+ dropped steadily with age in both men and women, and plasma NAD+ was lower in older adults across an age range of 20 to 87. Reviewers note, however, that human data on this decline are still limited, and nobody has shown at what level a drop starts to cause problems.
That decline is why NAD+ is sold as an anti-ageing supplement, in three main ways: NAD+ itself taken by mouth, NAD+ given as an IV drip or injection, and precursors (building blocks) the body turns into NAD+, chiefly nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). A 2026 systematic review of 33 human intervention studies found that oral NR and NMN consistently raised NAD+ markers and were well tolerated, but their effects on function, metabolism and other healthspan outcomes were mixed and often null.
NAD+ itself has much less research than its precursors. The same review found no outcome trial of IV or intramuscular NAD+ for anti-ageing or wellness. A 6-hour IV infusion in a small pilot did not raise plasma NAD+ for the first 2 hours, and IV NAD+ commonly causes stomach upset and chest pressure during the drip. The only randomised trial of an oral NAD+ product (a modified formulation, tested for 5 days) raised NAD+ inside blood cells by 53% versus placebo, without changing plasma NAD+.
In short: raising NAD+ is achievable, but whether doing so improves health, energy or ageing in people is still unknown. If you want to try it, oral NR or NMN have far more safety and dose data than NAD+ drips, and none of them should replace treatment for a diagnosed condition.
How It Works
- NAD+ shuttles electrons in the reactions that turn food into cellular energy (ATP), alternating with its reduced form, NADH.
- It is consumed by PARP enzymes that repair DNA; in human skin, higher PARP activity with age went with lower NAD+.
- Sirtuins, enzymes that switch genes on and off, need NAD+ to work, which is the basis for the anti-ageing hypothesis.
- NAD+ given by IV is broken down quickly; in one pilot it was completely removed from plasma for at least the first 2 hours.
- Precursors such as NR and NMN enter cells and are rebuilt into NAD+, which is why they raise blood levels more predictably.
Quick Facts
- Coenzyme in every cell
- Levels fall with age in skin and plasma
- NR and NMN reliably raise blood NAD+
- No outcome trials of IV NAD+
- IV drips often cause nausea, chest pressure
- Health benefits in people unproven
Benefits & Outcomes
No linked outcomes yet. Research is ongoing.
Health Concerns Addressed
No linked health concerns yet.
Supporting Research15 studies
Oral LNAD+ rapidly elevates whole blood intracellular NAD and metabolic flux without elevating plasma NAD: evidence from a randomized controlled trial
Kornilov SA, Hastings WJ, McGrath LF +4 more
LNAD+ produced a rapid and pronounced increase in icNAD
A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD
Grant R, Berg J, Mestayer R +4 more
NAD+ is rapidly and completely removed from the plasma for at least the first 2 h
Intravenous infusion of nicotinamide adenine dinucleotide (NAD+) versus nicotinamide riboside (NR): a retrospective tolerability pilot study in a real-world setting
Reyna K, Heinzen G, Patel N +4 more
NAD+ IV reported moderate to severe gastrointestinal symptoms
Randomized, placebo-controlled, pilot clinical study evaluating acute Niagen®+ IV and NAD+ IV in healthy adults
Hawkins J, Idoine R, Kwon J +4 more
an increase in white blood cell counts and neutrophils was observed in the NAD+ IV condition
NAD⁺ supplementation for anti-aging and wellness: A PRISMA-guided systematic review of preclinical and clinical evidence
Gallagher C, Emmanuel OO
clinical effectiveness for anti-aging or wellness outcomes remains inconclusive
The Plasma NAD+ Metabolome Is Dysregulated in "Normal" Aging
Clement J, Wong M, Poljak A +2 more
a significant decline in the plasma levels of NAD+
Age-associated changes in oxidative stress and NAD+ metabolism in human tissue
Massudi H, Grant R, Braidy N +3 more
A strong negative correlation was observed between NAD(+) levels and age
Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults
Conze D, Brenner C, Kruger CL
dose-dependently and significantly increased whole blood NAD+
Nicotinamide riboside is uniquely and orally bioavailable in mice and humans
Trammell SA, Schmidt MS, Weidemann BJ +4 more
single doses of 100, 300 and 1,000 mg of NR produce dose-dependent increases
Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults
Martens CR, Denman BA, Mazzo MR +5 more
effectively stimulates NAD+ metabolism in healthy middle-aged and older adults
Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study
Dellinger RW, Santos SR, Morris M +4 more
NAD+ levels increased by approximately 40% in the NRPT 1X group
Nicotinamide Riboside Augments the Aged Human Skeletal Muscle NAD+ Metabolome and Induces Transcriptomic and Anti-inflammatory Signatures
Elhassan YS, Kluckova K, Fletcher RS +4 more
NR elevated the muscle NAD+ metabolome
The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson's disease
Brakedal B, Dölle C, Riemer F +4 more
NR treatment was well tolerated and led to a significant, but variable, increase in cerebral NAD levels
Effects of NAD+ precursor supplementation on glucose and lipid metabolism in humans: a meta-analysis
Zhong O, Wang J, Tan Y +1 more
NAD+ precursor can significantly reduce TG level
Safety and Metabolism-Related Outcomes of Oral Nicotinamide Mononucleotide Supplementation in Adults: A Systematic Review and Meta-Analysis
Yang W, Huang J, Tang Z +2 more
Broad metabolic benefits were not evident
Safety Information
Potential Side Effects
Oral NAD+ was well tolerated in its one 5-day trial, with a single case of mild nausea. IV NAD+ commonly causes moderate to severe stomach symptoms, a faster heart rate and chest pressure during the infusion; these settled when the drip ended, but they forced slower infusions. One pilot also found a rise in white blood cells and neutrophils after IV NAD+, suggesting an inflammatory response. Oral NR and NMN caused no more adverse events than placebo in trials of up to 8 and 24 weeks.
Contraindications
No formal contraindications have been studied. Pregnancy and breastfeeding have no safety data. IV NAD+ needs medical supervision because of chest pressure and heart-rate changes during infusion; people with heart disease should discuss it with their cardiologist first.
Drug Interactions
- No interaction studies exist for NAD+ itself; tell your prescriber before starting it, especially if you take several medicines.
- Diabetes or cholesterol medicines: NAD+ precursors shifted lipids and slightly raised plasma glucose in a meta-analysis (mostly from nicotinic acid), so recheck your numbers if you add one.
Pregnancy & Breastfeeding
Pregnancy: Not enough evidence to judge
Breastfeeding: Not enough evidence to judge
Dosage Guidelines
Dosage Used in Studies
Consult healthcare provider
Best Time to Take
No study has compared morning and evening dosing of NAD+ or its precursors. Trials gave oral precursors once or twice a day, and blood NAD+ stayed raised throughout an 8-week NR trial, so consistency matters more than the time of day as far as the data go.
Best Form
For raising blood NAD+, oral NR or NMN: both have several randomised trials and safety data over weeks to months. Oral NAD+ has one 5-day trial, and IV NAD+ has tolerability problems and no outcome trials.
Bioavailability
NAD+ is broken down quickly outside cells. During a 6-hour IV infusion, plasma NAD+ did not rise for the first 2 hours, and breakdown products then appeared in urine. One oral formulation raised NAD+ inside blood cells by 53% in 5 days without raising plasma NAD+. Precursors are better studied: a single oral dose of NR raised the blood NAD+ metabolome in a dose-dependent way.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| Oral NAD+ | No evidence-based dose | The only randomised trial of oral NAD+ lasted 5 days and used a proprietary formulation; its abstract does not state the dose. No longer trials exist. |
| IV NAD+ (as given in clinics) | 500 mg per infusion, studied for 1-4 days | Described in a retrospective clinic review and a pilot trial, not established as effective. Infusions averaged 97 minutes because of side effects. |
| Nicotinamide riboside (adults) | 100-1,000 mg daily | Studied for up to 8 weeks in healthy overweight adults; NAD+ rose with dose. 1,000 mg a day was used in older men and in early Parkinson's disease. |
| NMN (adults) | 250-2,000 mg daily | Range used across 15 randomised trials lasting 14 days to 24 weeks. Long-term safety beyond that is unknown. |
Forms Compared
Oral NAD+ (capsules, powders)
Best for Unproven; little data
One 5-day randomised trial of a modified formulation raised NAD+ in blood cells by 53% but not plasma NAD+. Standard NAD+ capsules have no published human data.
IV NAD+ drip
Best for Not recommended outside research
Commonly 500 mg per infusion in clinics. Causes stomach upset, faster heart rate and chest pressure during the drip, so infusions run slowly. No outcome trials.
NAD+ injections (subcutaneous or intramuscular)
Best for Unproven
Sold by wellness clinics; we found no published peer-reviewed trial of injected NAD+ for any health outcome.
Nicotinamide riboside (NR)
Best for Raising blood NAD+
Precursor. 100-1,000 mg a day raised whole-blood NAD+ by 22-142% within 2 weeks in an 8-week trial, with no more side effects than placebo.
Nicotinamide mononucleotide (NMN)
Best for Raising blood NAD+
Precursor. Trials used 250-2,000 mg a day for up to 24 weeks without more adverse events than placebo. See our NMN page.
Niacin and nicotinamide (vitamin B3)
Best for Lipids (prescribed niacin)
The classic precursors. In a meta-analysis, nicotinic acid drove most of the lipid changes from NAD+ precursors, and precursors overall raised plasma glucose slightly.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.