NAD+, nicotinamide, and niacinamide get used interchangeably in skincare marketing. They are related but distinct, and the human evidence behind them is not interchangeable at all. One has a genuine phase 3 trial. The others do not.
Skin Science
Published by Astra, which offers some of the treatments discussed. Educational, not medical advice.
Start with the vocabulary problem, because it is the root of most NAD+ skincare confusion. NAD+ (nicotinamide adenine dinucleotide) is the coenzyme itself, the molecule that participates directly in cellular energy production and DNA repair reactions. It is not the same molecule as nicotinamide, and it is not the same molecule as niacinamide, even though all three names show up interchangeably on product labels.
Nicotinamide and niacinamide are, in fact, the same chemical: niacinamide is simply the more common cosmetic-industry name for nicotinamide, a form of vitamin B3. The body can convert nicotinamide into NAD+ through a metabolic pathway, but nicotinamide is not itself NAD+, and taking or applying nicotinamide is not the same intervention as raising cellular NAD+ directly. This distinction is not pedantic. The clinical trial evidence below belongs almost entirely to nicotinamide, taken orally, tested against skin cancer. It does not automatically transfer to topical niacinamide creams, and it does not automatically transfer to NAD+ itself, injected or otherwise.
Keeping these three separate is the single most useful thing a reader can do before evaluating any NAD+-and-skin claim. Ask which of the three the study actually used, and whether it was taken orally, applied topically, or infused. The answer changes what the study can and cannot tell you.
The strongest piece of clinical evidence in this entire family belongs to oral nicotinamide, and it is a genuinely good trial. The ONTRAC study was a phase 3 randomized controlled trial testing oral nicotinamide for skin-cancer chemoprevention 1. The population matters as much as the result: participants had a history of at least two non-melanoma skin cancers in the previous five years, meaning this was a group already established as very high-risk for developing more.
In that specific population, oral nicotinamide reduced the rate of new non-melanoma skin cancers compared to placebo over the treatment period. That is a real, positive, phase 3 result, and it is the reason nicotinamide (not niacinamide cream, not NAD+ injection) has a legitimate place in dermatology's skin-cancer prevention conversation for high-risk patients.
The result belongs specifically to that population and that route of administration: high-risk patients with a documented history of multiple prior skin cancers, taking nicotinamide by mouth. It is not a general population result, and it is not evidence about preventing a first skin cancer in someone without that history, nor about slowing normal skin aging in a healthy adult.
Good science replicates a promising result in a second population before treating it as settled, and that happened here. A follow-up phase 3 randomized trial tested the same oral nicotinamide for skin-cancer chemoprevention in organ transplant recipients, another population at substantially elevated risk of skin cancer because of long-term immunosuppressive therapy 2. This trial, sometimes referred to as ONTRANS, found that nicotinamide did not reduce the rate of skin cancers in this group compared to placebo.
Put the two trials side by side deliberately, because the honest lesson is in the comparison, not in either result alone. ONTRAC: high-risk patients with a history of multiple prior non-melanoma skin cancers, immunocompetent, nicotinamide reduced new cancers. ONTRANS: high-risk patients who were organ transplant recipients on immunosuppression, nicotinamide did not reduce new cancers.
A null replication in a different population is not automatically a contradiction. It could mean immunosuppression changes the biology enough that the same chemopreventive mechanism does not work as well, or it could mean the original result was narrower than it first appeared. Either way, the honest reading is that oral nicotinamide's skin-cancer benefit is not a universal effect that generalizes across every high-risk group. It worked in one defined population and did not in another, and both facts belong in the same sentence whenever this trial gets cited.
Separate again from the skin-cancer trials above is the case for topical niacinamide as a cosmetic skincare ingredient, which is the context most people actually encounter it in, in serums and moisturizers. The relevant human study here is small and tested cosmetic appearance, not disease prevention. It examined topical niacinamide's effect on the appearance of aging facial skin, evaluating outcomes like the visible look of fine lines and skin tone rather than any medical endpoint 4.
This is worth being precise about, because it is a different category of evidence than ONTRAC and ONTRANS entirely. It is a small human study with cosmetic, appearance-based endpoints, not a phase 3 disease-prevention trial. That does not make it worthless, but it means topical niacinamide's evidence base sits in a different, more modest tier than the skin-cancer chemoprevention data for oral nicotinamide. The two should not be cited as if they support the same claim.
None of the trials above tested NAD+ itself, injected or otherwise, against a skin outcome. What supports the idea that NAD+ matters for skin at all is the general finding that NAD+ concentrations decline with age in human tissue, shown in tissue studies that are not skin-specific outcome trials but part of the broader aging literature 35. That decline is measured, but it is correlational with age generally; it is not a trial showing that restoring NAD+ improves any specific skin outcome.
So here is the honest state of the field, stated plainly because Astra sells NAD+ injection and this is the section where that costs us something to say clearly: there is no published clinical trial of injectable NAD+ for any skin endpoint. Not wrinkle depth, not skin cancer, not skin appearance, not skin barrier function. The skin case for injectable NAD+ rests on borrowed logic, that NAD+ declines with age generally and that raising it should help cells including skin cells function better, not on a direct trial testing that idea in skin.
That is a meaningfully weaker evidentiary position than oral nicotinamide holds for skin-cancer chemoprevention in high-risk patients, and it is worth knowing before anyone chooses an NAD+ product specifically for a skin goal.
NAD+, nicotinamide, and niacinamide are three names on the same family tree, and only one of them has walked through a phase 3 trial with a skin-cancer endpoint. Marketing rarely says which one it means.
Astra Editorial, reviewing the NAD+ and skin literature
No. Nicotinamide and niacinamide are the same compound, a form of vitamin B3, with niacinamide being the more common cosmetic-industry name. NAD+ is a different molecule, the coenzyme the body makes from nicotinamide and other precursors. The clinical evidence for each is not interchangeable.
In one specific high-risk population, yes: the ONTRAC phase 3 trial found oral nicotinamide reduced new non-melanoma skin cancers in people with a history of at least two prior skin cancers 1. That result did not replicate in organ transplant recipients in the follow-up ONTRANS trial 2.
ONTRAC enrolled immunocompetent high-risk patients; ONTRANS enrolled organ transplant recipients on long-term immunosuppression. A null result in a second, biologically different high-risk population is a meaningful caution against assuming the first trial's benefit generalizes everywhere, rather than a simple contradiction.
There is a small human study of topical niacinamide on the appearance of aging facial skin, using cosmetic endpoints like fine lines and tone rather than disease outcomes 4. It is a modest evidence base, distinct from the skin-cancer chemoprevention trials of oral nicotinamide.
No. As of this writing there is no published clinical trial testing injectable NAD+ against any skin outcome. The idea that NAD+ injections help skin rests on general tissue-aging evidence, not a direct skin trial.
NAD+ decline with age has been measured in human tissue broadly, which supports the general premise, but the studies behind that finding are not skin-specific outcome trials 35.
Astra offers compounded NAD+ injection on the strength of the broader NAD+ and precursor literature discussed elsewhere in this library, not on a skin-specific trial, because none exists yet. If a skin outcome is your specific goal, that gap is worth knowing before you start.
Astra's compounded NAD+ injection program is prescribed and supervised by a licensed physician and dispensed by a state-licensed US compounding pharmacy. It is not FDA-approved, and there is no published clinical trial of injectable NAD+ for any skin endpoint specifically. If skin is your primary goal, weigh that gap alongside the broader NAD+ evidence discussed here.
This guide is educational and is not medical advice. Compounded medications are not FDA-approved. Speak with a licensed physician about your own care.