Two people can both say they take NAD⁺ and be buying products that share a name and almost nothing else. One needed a prescriber, a pharmacy and a medical intake. The other was added to a basket like a bottle of vitamin D. They sit under different sections of federal law, and the difference decides who may sell it to you, what it had to demonstrate first, and what exists to fall back on if something goes wrong.
Of the 166 sellers we have reviewed, 139 require a prescription and 27 do not. That is not a quality split. It is a split in which rulebook applies.
A compounded prescription drug
This is the injection, the IV and most of the nasal sprays — 129 of the sellers we review. A prescriber writes for you, a licensed pharmacy makes it, and the whole thing is legal because compounding for an individual patient is carved out of the approval requirements that apply to manufactured drugs.
The carve-out is the point, and it cuts both ways. Nothing here is FDA-approved, and the FDA does not review it for safety, efficacy or quality before it is dispensed. What you gain is a chain of accountable, licensed parties: a prescriber who can lose a license and a pharmacy that can be inspected. That chain is only usable if you know who is in it, and most sellers will not name the pharmacy.
A dietary supplement
This is the capsule, and it is a completely different legal object. No prescription, no pharmacy, no prescriber — and no pre-market review of whether it works or whether the bottle contains what the label says. A supplement maker is responsible for its own product’s safety and for not making disease claims; nobody checks first.
There is a second distinction inside this category that the shelf hides. Many oral products are not NAD⁺ at all but a precursor — nicotinamide riboside or NMN — which the body converts. That is not a criticism: the precursors are the only form in this whole category with randomized human trials behind them, which is the comparison worth reading. But it does mean “an NAD⁺ supplement” and “an NAD⁺ injection” can be different molecules, and the oral-versus-injection question is not the same question as which one is stronger.
A topical or cosmetic product
Patches and creams are the third category and the loosest. A product applied to skin and sold for appearance is not required to demonstrate effectiveness to anyone before sale. There is no prescriber, no pharmacy, and no dossier — the manufacturer is responsible for safety and for staying inside cosmetic claims.
That is a very long way from the compounded injection at the other end of this article, and the two are advertised in nearly identical language. What a patch is being asked to do — move a large molecule across skin and into the blood — is the hard part, and it is the part the label skips.
What this changes for you
Not which one to buy. All three are legal, and none of them had to prove to a regulator that it produces the benefit it is sold for — that is the one thing they genuinely have in common, and it is worth sitting with.
What it changes is which questions are even available to ask.
- Prescription product: who is the prescriber, which pharmacy compounds it, under 503A or 503B, and can I have a certificate of analysis? Those sections mean something.
- Supplement: which molecule, at what milligram dose, and is there third-party testing? There is no regulator to ask, so the label and the seller are the whole record.
- Topical: what is the evidence that anything crosses the skin at all? This is the question the category is least able to answer.
A seller who cannot say which of the three they are selling has answered the most basic question badly. Most can, and the answer is usually visible from whether they want a medical intake before showing you a price — which is its own tell.