NAD supplements have proliferated rapidly: NMN, NR, niacin, niacinamide, and various proprietary blends all claiming to boost NAD levels. The basic biology is real — these are precursors your body can convert to NAD — but quality, dosing, and evidence vary substantially across products.
Here’s a clear comparison of the major NAD supplements, what the research actually shows, and how to pick a product worth your money.
For background, see NAD+, what is NAD, and NAD benefits.
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Available on the App StoreQuick comparison
| Supplement | Form | Best evidence | Typical dose | Cost |
|---|---|---|---|---|
| NMN (nicotinamide mononucleotide) | Capsule, sublingual | Improved walking distance, biological age markers, NAD elevation1 | 300–600 mg/day | $$$ |
| NR (nicotinamide riboside) | Capsule | NAD elevation, generally clean safety2 | 250–500 mg/day | $$$ |
| Niacin (nicotinic acid) | Capsule, tablet | Cholesterol effects, NAD elevation | 500–1000 mg/day (high dose) | $ |
| Nicotinamide | Capsule | NAD elevation, less efficient than NMN/NR | 500 mg/day | $ |
| NADH | Sublingual tablet | Limited absorption data | 5–20 mg/day | $$ |
| IV NAD+ | Infusion | Direct delivery, expensive, thin evidence | 250–1000 mg/session | $$$$ |
NMN (nicotinamide mononucleotide)
The most direct of the oral precursors. Just one enzymatic conversion away from NAD itself.
Evidence
A 2022 dose-response randomized trial in 80 healthy middle-aged adults tested 300, 600, and 900 mg/day NMN against placebo for 60 days.1 Findings:
- All three doses raised blood NAD significantly
- 600 mg produced the largest blood NAD increase
- All three doses improved walking distance vs. placebo
- All three doses improved subjective health (SF-36 scale)
- Biological age (algorithm-based) didn’t worsen in NMN groups while it did in placebo
- Excellent safety profile across all doses
Pros
- More direct conversion to NAD than other precursors
- Strong recent positive trial data
- Generally good tolerability
Cons
- Expensive ($30–80/month for quality products)
- FDA changed its position on NMN as a dietary supplement in 2022, creating regulatory uncertainty for some products
- Long-term safety data still limited
Practical
Take 300–600 mg in the morning, with or without food. Most published positive trials used 250–600 mg daily.
NR (nicotinamide riboside)
The first NAD precursor to gain widespread research interest. Most often sold under brand names like Tru Niagen.
Evidence
A 2020 review summarized over a decade of human research on NR.2 Multiple trials confirm:
- NR reliably raises blood NAD levels
- Generally well-tolerated
- Modest improvements in cardiovascular markers in some trials
- Some signals for metabolic and inflammatory improvements
Pros
- More long-term human data than NMN
- Clean safety record
- Stable shelf-life
- Branded versions (Niagen) have undergone GRAS safety reviews
Cons
- Effects on functional outcomes (performance, biological markers) more modest than recent NMN trials
- Branded products are particularly expensive
Practical
Take 250–500 mg daily, morning. Most trials use this range.
Niacin (nicotinic acid)
The oldest and cheapest NAD precursor.
Evidence
- Effective at raising NAD levels at high doses (500–1,000 mg/day)
- Established cholesterol-lowering effects (raises HDL, lowers LDL and triglycerides)
- Used clinically for decades for dyslipidemia
Pros
- Cheap (a few dollars/month)
- Long safety record at standard doses
- Cholesterol benefits are a useful side effect
Cons
- “Niacin flush” — face/upper body flushing, itching, warmth — at higher doses, can be uncomfortable
- High-dose chronic use can affect liver function (rare but real)
- “Sustained release” forms have higher liver-effect risk than immediate release
- Not the choice if you’re sensitive to flushing
Practical
Start very low (50–100 mg) to test flush response. Build up over weeks. 500–1000 mg/day at higher doses requires medical guidance, especially with sustained-release forms.
Suggested read: Methylene Blue Dosage: Safe Doses by Use Case
Nicotinamide
Niacin’s amide form. Doesn’t cause flushing.
Evidence
- Raises NAD levels
- Less efficient than NMN or NR for raising NAD
- Used clinically for niacin deficiency, some skin conditions
Pros
- Cheap
- No flush
- Long safety record
Cons
- Lower efficiency at raising NAD compared to NMN/NR
- High doses can affect glucose metabolism (rare)
Practical
500 mg/day. A reasonable budget option for general NAD support.
NADH
A reduced form of NAD sold sublingually.
Evidence
- Limited absorption data
- Some smaller studies suggest energy and cognitive effects in chronic fatigue
- Generally considered less efficient than NMN/NR
Pros
- Sublingual route bypasses some digestion
- Generally well-tolerated
Cons
- Limited evidence base
- Often paired with other ingredients in proprietary blends, hiding doses
Practical
Generally not the first choice given more direct alternatives.
IV NAD+
Direct infusion of NAD.
Evidence
- Bypasses oral bioavailability limitations
- Strong on marketing, lighter on independent published evidence
- Most published NAD research uses oral precursors, not IV
Pros
- Direct delivery
- Some clinical use for specific conditions (addiction recovery, severe fatigue) under medical supervision
Cons
- Expensive ($250–500/session)
- Side effects more pronounced (nausea, chest tightness during infusion)
- Limited independent research base
- Not regulated for “wellness” use
Practical
Reasonable for specific clinical scenarios under medical care. Skeptical for routine wellness use. See NAD injections.
Which to choose
A practical decision tree:
“I want the most evidence-backed option”
NR or NMN — both have published RCT data, both raise NAD, both have clean safety. Recent NMN trials have stronger functional outcome data; NR has more long-term human data.
“I want the cheapest reasonable option”
Niacin — pennies per day, with cholesterol benefits as a bonus. Tolerate the flush or use a different form.
Suggested read: Magnesium Glycinate vs Citrate: Which Is Better for You?
“I want maximum effect”
NMN at 600 mg/day — based on the dose-response data showing 600 mg produced the largest NAD elevation and walking-distance improvement.
“I’m cost-sensitive but want NMN-class effects”
Lower-dose NMN (300 mg/day) — also showed significant improvements in the 2022 RCT, just smaller than 600 mg.
“I want IV NAD”
Have specific reasons (medical condition, prescribing physician oversight). Not optimal for general wellness.
Quality signals to look for
The supplement industry varies dramatically. Check for:
- Third-party testing — USP, NSF, ConsumerLab, Informed Sport
- Specific dose disclosure — exact mg of NAD precursor per capsule, not “proprietary blend”
- Third-party purity testing — for heavy metals and contaminants
- Reputable brand with consistent quality history
- Stability info — refrigeration recommendations for some forms
- Realistic claims — avoid products promising dramatic effects
Brand recommendations come and go; the principles above don’t.
Common questions
Should I take NAD daily or cycle on/off? Most published trials use continuous dosing. Cycling isn’t well-studied. Daily appears safe based on available data.
Time of day to take it? Morning generally; may be activating for some people if taken late.
With food or empty stomach? Either works. With food may reduce mild GI effects.
Can I take NAD precursors and niacin together? Possible but not necessarily additive. The body’s regulation may limit total NAD elevation regardless of how many sources you provide.
Is it safe long-term? Most trial data is up to 6–12 months. Long-term human data is limited. Major safety signals haven’t emerged so far.
Will it interact with my medications? Generally low interaction profile. Niacin specifically can interact with statins (myopathy risk) and blood thinners. Check with a pharmacist.
Bottom line
For most adults wanting to try NAD supplementation: NMN at 300–600 mg/day or NR at 250–500 mg/day are the evidence-backed defaults. Niacin is the budget option that doubles as cholesterol support. IV NAD has thin independent evidence and isn’t optimal for routine wellness. Quality, third-party tested products from reputable brands are worth paying for in this category. Manage expectations: NAD precursors deliver modest, real benefits — not transformative anti-aging effects.
Yi L, Maier AB, Tao R, 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;45(1):29-43. PubMed ↩︎ ↩︎
Mehmel M, Jovanović N, Spitz U. Nicotinamide Riboside-The Current State of Research and Therapeutic Uses. Nutrients. 2020;12(6):1616. PubMed ↩︎ ↩︎
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