NAD+ Boosters Explained: NMN, NR, Niacin and Sirtuin Supplements

An NAD+ booster is any product meant to raise NAD+, the coenzyme your cells use to make energy and run repair enzymes, including sirtuins. The label covers very different things: vitamin B3 forms like NMN, NR and niacin, NAD+ itself, and “sirtuin supplements” such as resveratrol that do not raise NAD+ at all. This guide sorts them by what human studies actually show.

It is educational, not medical advice.

Key Takeaways

• NR and NMN have the best human evidence for raising NAD+. In an 8-week trial, NR raised whole-blood NAD+ by 22%, 51% and 142% at 100, 300 and 1,000 mg a day, and several NMN trials found similar rises.
• Niacin works but is harder to take. The original B3 form raises NAD+ but causes skin flushing, and high doses need medical supervision.
• Direct NAD+ needs a route around digestion. Swallowed NAD+ is largely broken down before absorption; nasal and IV routes are used to get around that.
• “Sirtuin supplements” are a different category. Resveratrol and pterostilbene do not raise NAD+; they are studied as activators of sirtuins, the enzymes that use NAD+, which is why they are often paired with NMN.
• Side effects are usually mild, most often nausea, headache or stomach upset, with flushing mainly from niacin.

What Is an NAD+ Booster?

NAD+ (nicotinamide adenine dinucleotide) is used by every cell to turn food into energy and to power enzymes that repair DNA and regulate metabolism, including the sirtuins. Levels tend to fall with age. An NAD+ booster tries to push them back up in one of four ways:

• Supplying a building block the body turns into NAD+ (NMN, NR, niacin, nicotinamide).
• Supplying NAD+ itself (nasal sprays, IV, and oral NAD+).
• Slowing NAD+ breakdown, for example by blocking the enzyme CD38 (so far studied mostly in animals).
• Acting on the enzymes that use NAD+, such as sirtuins (resveratrol, pterostilbene). These are often sold alongside boosters but do not raise NAD+.

For the background, see why NAD+ declines with age and NAD+ and sirtuins explained. Each booster enters a different step of NAD+ production; see how NAD+ is made.

NAD+ Boosters Compared

Booster	How it works	Human evidence for raising NAD+	Main drawback
NR (nicotinamide riboside)	B3 form, converted to NMN then NAD+	Strong: dose-dependent rises in randomized trials	Cost; long-term data limited to months
NMN (nicotinamide mononucleotide)	One step from NAD+	Strong: blood NAD+ rose in several randomized trials	Cost; long-term data limited to months
Niacin (nicotinic acid)	Classic B3 vitamin	Raises NAD+	Skin flushing; high doses need supervision
Nicotinamide	B3 form in multivitamins	A precursor the body turns into NAD+	Very high doses can cause side effects
NAD+ itself	Delivered by nasal spray, IV or capsule	Studied mainly as IV infusions	Swallowed NAD+ is largely broken down first
Resveratrol, pterostilbene	Aimed at sirtuins, not NAD+ levels	Do not raise NAD+	Work on sirtuins rather than NAD+, so usually paired with an NAD+ precursor

NR: The Most-Measured NAD+ Booster

NR has the clearest dose-response data. In an 8-week randomized trial of healthy overweight adults, 100, 300 and 1,000 mg a day raised whole-blood NAD+ by 22%, 51% and 142% within two weeks, and the rises held for the rest of the study (Conze et al., 2019). In a 6-week crossover trial in healthy middle-aged and older adults, 1,000 mg a day was well tolerated and raised NAD+ in blood cells (Martens et al., 2018).

NMN: One Step From NAD+

NMN is the molecule your cells make from NR on the way to NAD+. In a 60-day randomized trial of 80 healthy adults aged 40 to 65, 300, 600 and 900 mg a day all raised blood NAD+, with the best functional results at 600 mg (Yi et al., 2023). Our NMN benefits guide covers the rest of the trials, and NMN vs NR compares the two head to head. For what the trials measured in women specifically, see our guide to NMN for women over 40 and over 50.

Niacin and Nicotinamide

Niacin (nicotinic acid) and nicotinamide are the older, lower-cost B3 forms. Niacin raises NAD+ but causes the well-known “niacin flush” of warmth, redness and itching, and high doses can affect the liver and blood sugar, so they are best used with medical guidance. Nicotinamide does not cause flushing, but very high doses have their own side effects. Both are in many multivitamins at small amounts.

Direct NAD+: Nasal, IV and Oral

Swallowed NAD+ is largely broken down in the gut into smaller pieces before it is absorbed, so most oral NAD+ ends up acting like a precursor. IV NAD+ avoids that but takes hours and often causes nausea or chest pressure if given too quickly. A nasal spray is a needle-free middle ground: it is absorbed through the lining of the nose instead of being swallowed like a capsule, so some of each dose skips digestion. Most human NAD+ research has used oral precursors or IV infusions. See NAD+ nasal spray vs oral NAD+ and NAD+ injections and IV.

For two other routes people ask about, see NAD+ patches vs NAD+ nasal spray and NMN nasal spray.

Best Sirtuin Supplement: NAD+ Precursors, Resveratrol and Pterostilbene

If you are searching for the best sirtuin supplement, start with how sirtuins work. Sirtuins are enzymes that need NAD+ to function, so their activity depends on how much NAD+ your cells have (Covarrubias and colleagues, 2021). That gives two ways to support them:

• Supply the NAD+ they run on. NMN and NR are turned into NAD+, as covered above.
• Act on the enzyme itself. Resveratrol and pterostilbene are studied as sirtuin activating compounds. In lab work, resveratrol and other activators switched on SIRT1 through a shared site on the enzyme when its natural partner proteins were present (Hubbard and colleagues, 2013). In a 30-day placebo-controlled crossover trial in 11 men, 150 mg of resveratrol a day activated AMPK and raised SIRT1 and PGC-1α protein levels in muscle (Timmers and colleagues, 2011).

Pterostilbene is a close relative of resveratrol found in blueberries. In an 80-person placebo-controlled trial, it was well tolerated at up to 250 mg a day for six to eight weeks (Riche and colleagues, 2013).

Supplement	What it does for sirtuins	Human research
NMN	Supplies NAD+, which sirtuins need	Raised blood NAD+ in several trials
NR	Supplies NAD+, which sirtuins need	Raised blood NAD+ in several trials
Resveratrol	Studied as a direct SIRT1 activator	Raised muscle SIRT1 protein in a 30-day trial
Pterostilbene	Resveratrol relative in the same family	Well tolerated up to 250 mg a day

That is why many formulas pair an NAD+ precursor with resveratrol or pterostilbene: one supplies NAD+, the other is aimed at the enzymes that use it. Our Enhanced NMN combines 750 mg of NMN with 200 mg of resveratrol and 100 mg of pterostilbene per two-capsule serving, plus TMG and vitamin B12. More in our NMN and resveratrol guide and pterostilbene guide.

Natural NAD+ Boosters

Some of the most reliable ways to support NAD+ cost nothing: regular exercise, consistent sleep, limiting alcohol, and enough protein and B vitamins in your diet. Our guide to increasing NAD+ naturally covers each one. Urolithin A is often mentioned alongside NAD+ boosters, but it works on a different step, clearing old mitochondria; see urolithin A vs NAD+. Our Urolithin A + Spermidine Capsules give 500 mg urolithin A and 6 mg spermidine per 2 capsules; join the waitlist on the product page to hear when they launch.

NAD+ Booster Side Effects

• NR and NMN: usually mild, such as nausea, headache, stomach upset or trouble sleeping if taken late. Trials used up to about 1,000 to 1,250 mg a day for weeks to months.
• Niacin: flushing, itching and, at high doses, liver and blood sugar effects.
• IV NAD+: nausea, cramping, flushing or chest pressure during the drip.
• Nasal NAD+: brief nasal stinging or irritation.

Check with a clinician if you are pregnant, breastfeeding, have a medical condition or take medication. See our full guide to NAD+ side effects and safety.

How to Choose the Best NAD+ Supplement

• Look for a studied form and dose: NR at 300 to 1,000 mg or NMN at 250 to 900 mg a day match what trials used.
• Check the label for exact amounts, not just a proprietary blend total.
• Choose third-party tested ingredients.
• Match the format to the job: a daily capsule for steady background support, a nasal spray if you want a needle-free way to take NAD+ itself.
• Know what was studied. Lifespan research on NAD+ boosters comes from animal studies.

Where Our Products Fit

Our Enhanced NMN gives 750 mg of NMN per two-capsule serving, with 200 mg of resveratrol, 100 mg of pterostilbene, 200 mg of TMG and methyl B12. TMG is included because the body uses methyl groups to clear extra nicotinamide.

Our NAD+ Nasal Spray delivers NAD+ itself in three strengths, 35 mg, 100 mg and 170 mg per two-spray serving. Many people use both: NMN as the daily baseline and the spray as a second, needle-free way to support NAD+. See can you take NAD+ every day for timing.

Sources

• Conze D et al. 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. Scientific Reports, 2019. PubMed
• Martens CR et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications, 2018. PubMed
• Yi L et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience, 2023. PubMed
• Covarrubias AJ et al. NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology, 2021. PubMed
• Hubbard BP et al. Evidence for a common mechanism of SIRT1 regulation by allosteric activators. Science, 2013. PubMed
• Timmers S et al. Calorie restriction-like effects of 30 days of resveratrol supplementation on energy metabolism and metabolic profile in obese humans. Cell Metabolism, 2011. PubMed
• Riche DM et al. Analysis of safety from a human clinical trial with pterostilbene. Journal of Toxicology, 2013. PubMed

Frequently Asked Questions

What is an NAD booster?

A product meant to raise NAD+, usually a vitamin B3 supplement such as NMN, NR, niacin or nicotinamide that the body turns into NAD+, or NAD+ itself delivered by nasal spray, IV or capsule.

What is the best NAD+ supplement?

For raising NAD+ levels, the best-studied NAD+ supplements are NR and NMN: randomized human trials show they raise blood NAD+ at 300 to 1,000 mg (NR) or 250 to 900 mg (NMN) a day. The best NAD+ supplement for you is a studied form at a studied dose, with every amount on the label and third-party tested ingredients. If you would rather take NAD+ itself without needles, a nasal spray is an option, though it has less published human data.

What is the best NAD booster?

NR and NMN have the most human evidence for raising NAD+, with randomized trials showing clear rises in blood NAD+. Niacin also works but causes flushing. The best choice depends on dose, budget and how you prefer to take it.

What is the best sirtuin supplement?

The best sirtuin supplement supports both sides of how sirtuins work: an NAD+ precursor such as NMN or NR to supply the NAD+ sirtuins need, and resveratrol or pterostilbene, which are studied as direct sirtuin activators. Many formulas, including our Enhanced NMN, combine the two. See the sirtuin section above for the research.

What supplements increase sirtuin activity?

NAD+ precursors such as NMN and NR support sirtuin activity by raising NAD+, the coenzyme sirtuins depend on. Resveratrol raised SIRT1 protein levels in muscle in a 30-day human trial, and pterostilbene is a related compound from the same family.

Are NAD boosters safe?

In trials, NR and NMN were well tolerated for weeks to months at up to about 1,000 to 1,250 mg a day. Side effects were usually mild. Long-term data over years are limited.

What are the side effects of NAD boosters?

Nausea, headache and stomach upset are the most common with NR and NMN. Niacin causes flushing. IV NAD+ can cause nausea or chest pressure during the drip.

What is a natural NAD booster?

Exercise, regular sleep, limiting alcohol and a diet with enough protein and B vitamins all support NAD+ without a supplement.

Can I take an NAD booster with an NAD+ nasal spray?

Yes, many people take a daily NMN or NR supplement and use an NAD+ nasal spray as well. Check with a healthcare provider if you take medication.

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.