Types of NAD+ supplements

NMN (Nicotinamide Mononucleotide)

NMN is a direct precursor to NAD+. Your body converts NMN into NAD+ through a single enzymatic step.

How it works: NMN enters cells (via the Slc12a8 transporter, discovered in 2019), then gets converted directly to NAD+ by the enzyme NMNAT.

The research: NMN became famous through David Sinclair’s longevity research at Harvard. Animal studies show impressive results: improved metabolism, better insulin sensitivity, and extended healthspan in mice. Human trials are newer but generally positive.

Key study: A 2022 study in Science gave older men 250mg NMN daily for 12 weeks. Results showed improved muscle insulin sensitivity and increased NAD+ levels.

Typical dose: 250-500mg daily
Cost: $40-$100/month

NR (Nicotinamide Riboside)

NR is another NAD+ precursor, but it converts to NAD+ through a slightly different pathway—first becoming NMN, then NAD+.

How it works: NR enters cells, gets converted to NMN by the enzyme NRK, then NMN becomes NAD+ via NMNAT. It’s a two-step process versus NMN’s one step.

The research: NR has more published human clinical trials than NMN. The compound is sold primarily as Tru Niagen (by ChromaDex) and has been studied in multiple double-blind, placebo-controlled trials.

Key study: A 2018 Nature Communications study showed NR supplementation increased NAD+ levels in humans by 40-90% depending on dose, with good tolerability.

Typical dose: 300-600mg daily
Cost: $40-$80/month

Direct NAD+ Supplements

Some supplements contain NAD+ itself rather than precursors.

How it works: In theory, you’re taking the end product directly. In practice, NAD+ is a large molecule that doesn’t absorb well through the gut. Most gets broken down during digestion.

The research: Very limited human data. Some studies suggest NAD+ may break down into its precursors (like NR) in the gut, then reassemble—essentially making it an expensive, indirect way to get NR.

Absorption and bioavailability

This is where marketing often misleads people.

The honest answer

Nobody knows exactly how much of any oral NAD+ precursor reaches your cells intact. Studies measure blood NAD+ levels increasing, which confirms something is working—but precise absorption rates remain debated.

What we know for sure:

• Both NMN and NR raise NAD+ levels in humans
• The increase is dose-dependent
• Individual response varies considerably
• Sublingual and liposomal formulations haven’t proven superior in rigorous trials

NMN vs NR: Which is better?

This is the most common question, and the honest answer is: we don’t know yet.

For deeper comparisons, see our NAD+ vs NMN guide and NMN vs NR guide.

Dosing guidelines

Timing

No strong evidence favors morning vs evening dosing. Most people take NAD+ supplements in the morning with or without food.

Some users report that high doses (500mg+) taken late in the day interfere with sleep—possibly due to increased cellular energy. If you notice this, switch to morning dosing.

Top supplement picks

Note: We don’t have affiliate relationships with these brands. Recommendations are based on third-party testing, company transparency, and user feedback.

Who should take which supplement?

Supplements vs injections vs IV

The trade-off: Supplements are cheapest and easiest but have the lowest absorption. IV therapy delivers the most NAD+ directly but costs 10-50x more.

Common path: Start with supplements. If no benefit after 2-3 months, try injections. IV therapy is typically reserved for loading phases or specific therapeutic goals.

What results to expect

Be realistic. NAD+ supplements aren’t magic pills.

What some people report:

• Improved energy (subtle, not dramatic)
• Better mental clarity
• Slightly improved exercise recovery
• Subjective “anti-aging” feelings

What the research shows:

• NAD+ blood levels increase (this is proven)
• Some metabolic markers may improve
• Dramatic reversal of aging is NOT demonstrated in humans
• Benefits vary between individuals

Timeline: Most people who notice effects report them within 4-8 weeks. If you’ve taken supplements consistently for 3 months without any benefit, they may not be worth continuing for you.

Frequently asked questions

The bottom line

NAD+ supplements—primarily NMN and NR—can raise your NAD+ levels. Whether that translates to meaningful health benefits depends on your age, health status, and expectations.

Our recommendation:

• Try NR (Tru Niagen) if you want the most-researched option
• Try NMN if you follow longevity research and prefer emerging science
• Skip direct NAD+ unless using sublingual/IV delivery
• Give any supplement 2-3 months before judging
• Consider injections if oral supplements don’t work