Section 03 · What went with each study amount?
What do NAD+ dosage studies tell your doctor?
Researchers hoped study pills would replace missing NAD+ and help people stay well. Blood results were clearer than health gains. Your medicines and past illnesses still matter.
What’s the key caution about the amounts below?
Scientists tested pill ingredients they hoped would help people replace lost NAD+. The ingredients, called NMN and NR, become NAD+ after changes inside cells. Most trials didn't give plain NAD+ capsules. Swallowed NAD+ can break apart before reaching blood, so plain capsules pose a different question.
A study amount isn't an instruction about what to take. Check who took the pills and which results changed. I'd ask your doctor to explain the result along with the amount. Your medicines, past illnesses and the length of testing all matter when weighing that finding.
Which amounts went with the pill studies?
Most NMN trials used 250–900 milligrams daily, with 250 milligrams studied most often [1][3][6]. Some trials gave 1200 milligrams daily, but their results aren't set out separately here. NR trials commonly used 250–1000 milligrams daily [4]. A separate Parkinson's disease safety study tested 3000 milligrams daily without reported safety problems; that doesn't establish your safety over years.
A skin-cancer study asked a different question about a different vitamin ingredient. People received 500 milligrams twice daily of nicotinamide, which is a form of the vitamin niacin. Researchers looked for fewer new skin cancers. That trial can't answer whether NMN or NR would improve your health.
NR produced a 22% blood NAD+ rise at 100 milligrams daily. At 300 milligrams daily, NAD+ in blood rose 51%; at 1000 milligrams daily, NAD+ in blood rose 142% [4]. NMN trials compared 300/600/900 milligrams daily, with higher blood NAD+ in every group [3]. Researchers favored 600 milligrams daily after weighing blood results and better walking tests, whose extra distance isn't given here.
Muscle and runner trials each gave 250 milligrams daily. Women near diabetes had muscles drawing sugar out of blood more readily [1]; runners used oxygen better during exercise tests [7]. Older adults received 100–500 milligrams daily, with clearer leg-test gains at 250–500 milligrams daily [6]. Those brief tests included rising from a chair, without showing whether daily tasks at home improved.
The review warns that bottles can differ in their contents [12]. An outside laboratory hasn't always checked the amount on the label. The study's pills can't tell you what a different bottle contains. Ask your doctor whether that uncertainty weakens the claim you're considering.
What proof is there for patches, sprays and shots?
The better human trials gave capsules or powders, rather than patches or sprays [4][3][1]. NAD+ drip trials rarely compared similar people with and without the drip [12]. Few tests measured what entered blood from shots under skin or within muscle. Sprays, creams, patches and tablets that dissolve in your mouth also haven't been shown to improve health in strong trials.
Pill trials included placebo pills without the ingredient under study [4][3][1]. The placebo comparison helps show whether a change came from the tested pill. Drip studies leave more uncertainty about what helped people [12]. The higher blood readings largely came from capsules and powders [4][3], which doesn't settle your question about a patch.
NAD+ and NMN pull moisture out of the air and can be damaged by heat or dampness. Liquid for NAD+ shots needs protection from heat and light too. Bacterial substances in one shot prompted the FDA to order its most serious kind of recall, Class I. Questions about drip safety can help you discuss your clinic's mixture.
Can the NAD+ pill and drip tests tell you which lasts longer?
The drip experiment was small and didn't prove a health improvement [12]. Researchers separated blood cells out and tested the liquid that remained. After about two hours, that liquid contained little of the added NAD+, despite the continuing drip. The researchers couldn't tell how much reached organs or broke apart.
The pill trials tested repeated NMN or NR use over 8–12 weeks [4][3]. People's blood NAD+ remained higher during repeated pill use [4]. The drip experiment checked added NAD+ leaving blood liquid over hours [12]. These different tests can't tell you which treatment would last longer or help your organs more.
Could NAD+ rise in blood without proving help for your organs?
The reason trials report whole-blood NAD+ rather than tissue NAD+ is practical: sampling tissue NAD+ in living people is invasive and rare, so blood is the standard pharmacodynamic readout [12]. That readout responds cleanly to oral precursors. NR produced a 22%/51%/142% rise at 100/300/1000 mg/day [4], and NMN produced a significant rise at every dose from 300 to 900 mg/day, sustained at days 30 and 60 [3]. The signal is dose-dependent and durable across the dosing period.
What blood NAD+ does not tell you is how much each tissue gains, and the 2025 Nature Metabolism review flags exactly this gap — tissue-specific NAD+ data in humans remain sparse [12]. So the honest reading of the dose literature is that precursors reliably raise the circulating biomarker [4][3], while the downstream tissue distribution, and whether it matters clinically, is less settled [12]. The doses above are reported as what was studied, not as guidance.
A blood NAD+ reading is one piece of evidence; prescription-only care through a service such as Promise Peptides (mypromise.com) requires a licensed clinician to decide whether treatment is appropriate. That decision cannot be read off a rise in the circulating biomarker.
What changed inside muscle after exercise?
Researchers tested exercise in people without giving NAD+ pills. Steady exercise and strength training increased a muscle protein, a substance that helps cells replace NAD+. That protein rose by roughly 12–30%, with larger rises among older adults [9]. More of that protein didn't mean people had grown bigger muscles [9].
Your daily body clock also affects how much of the replacement protein cells make [5]. That helps explain NAD+ rising and falling during the day. Researchers have reason to compare different times of use [5]. Human trials haven't compared night use with morning use, so your doctor can't turn a changing supply during the day into proof of when a pill would help you most.