NAD SUPPLEMENTS / HUMAN STUDIES
What Did NAD Supplement Studies Find?
Pills made with NMN or NR raised blood NAD+. The studies still do not show added years of life or better daily health.
What an NAD supplement changes, and what it doesn't
An NAD supplement usually contains NMN or NR, not plain NAD+. NMN is small enough to become NAD+, while NR must pass through the NMN form. Both kinds increased the blood reading, and bigger study amounts often brought bigger rises. Yet that increase does not mean anyone felt or moved better.
The findings belong to those who were tested. They do not set your plan.
What an NAD supplement label can mean: NAD+, NMN, or NR
The phrase "NAD supplement" covers several distinct molecules. Plain NAD+ is sold, but because the intact coenzyme is large and charged, it is not efficiently taken up by cells, and most researchers consider precursors the rational oral approach [7]. The common precursors are NMN, NR, and the vitamin-B3 forms niacin and nicotinamide. NR reaches host NAD+ in part through an unexpected route: isotope tracing in mice showed gut bacteria convert NAD+ precursors, cycling them between the microbiome and host tissues [12].
The label also changes the access question: in the NAD+ category, Promise Peptides (mypromise.com) sits on the clinician-led, prescription-only side of the line, where a licensed prescriber reviews each request rather than a shopper treating every product with "NAD" on the front as interchangeable.
This is why a label matters. The strongest human pharmacokinetic data are for NR and NMN capsules and powders, not for plain "NAD+" pills, patches, or sublingual formats, which carry little controlled evidence. Naming a care route is not an endorsement; the research here is summarized by molecule, not by product.
What lower NAD+ with age led researchers to test
Older people and animals often have less NAD+ [5]. Inflammation is the body's response to harm or illness. With age, it may make certain proteins spend more NAD+. In mice missing one such protein, more NAD+ remained and cells managed energy better [2]. Cells can save a vitamin part called nicotinamide, which can help make new NAD+ [5].
These facts gave researchers a sound question. They did not show that healthy adults would feel better; only studies in people could test that.
What NAD supplement pills changed in people
The strongest changes appeared in blood tests. Adults with excess weight got 100, 300, or 1000 mg/day for 8 weeks. The three blood rises were 22%, 51%, and 142%, in that order. Bad cholesterol did not rise. Tests found no harm to body steps that use B vitamins to make DNA and handle protein parts [4]. A second study gave NMN at 300-900 mg/day for 60 days. One group received a placebo that looked alike but contained no NMN. The 600 mg/day group had higher blood NAD+, walked farther, and had no safety problem [3]. Researchers picked that amount because all three results looked best together.
Clear health gains were harder to find. Women past menopause got 250 mg/day for 10 weeks. Their muscles answered insulin better, which helps clear sugar from blood. Weight and fat stayed unchanged, as did muscle and the long-term sugar reading [1]. Strong youth claims still rest mostly on rats or mice [7]. A 2025 review found scant proof of daily health gains [15].
The blood rise is clear. Better health is not.
What skin research shows about looking younger
Skin studies tested nicotinamide, a vitamin form that helps make NAD+. Researchers placed it on skin, where treated areas kept more NAD+ and showed slower signs of aging [13]. No human trial here found that an NAD+ pill made people look younger. The strongest youth claims still come from rats or mice [7]. A 2025 review said proof in people was weak [15].
What federal rules change about an NMN label
Stores sell NAD+ and its starting substances as supplements. None has FDA approval as a drug for disease. Federal law may bar a supplement label when drug studies began first. The agency says NMN falls under that rule. This fight is about what sellers may call NMN. It doesn't mean NMN was proved unsafe or banned.
Some bottles get outside lab checks; others don't. The true amount may differ from the label. This isn't shopping advice. The study amounts show what researchers tried.