NAD+

NAD+ is a coenzyme — nicotinamide adenine dinucleotide — that every cell in the body already makes and uses. That is the first thing to hold onto, because it separates NAD+ from most of this catalogue: it is not a synthetic peptide developed in a lab, it is a molecule your metabolism runs on. What is being sold is a way of supplying more of it, or of supplying something the body turns into it.

Why the format is the whole question

NAD+ turns up in wildly different products that get discussed as if they were one thing. An intravenous drip administered in a clinic, an injectable vial, and an oral precursor such as a nicotinamide compound are three different propositions with three different handling stories, and the debates about absorption and what actually reaches a cell are real and unsettled. A page or a seller that talks about "NAD" without saying which of these they mean has skipped the only question that changes anything.

What the vial format changes

Supplied lyophilized in a vial and reconstituted before use, in more than one strength. The reconstitution, storage and stability questions are the standard ones, and they matter here as much as anywhere — a coenzyme is not exempt from needing a certificate and a cold chain.

What to ask before ordering

The usual four — what it is, where and to what standard it was made, what the lot certificate shows, what the label states as intended use — plus the format question stated first: which product is this, and is the comparison I am making against a like product or against a different one entirely.

What we are not claiming

Anything about energy, ageing, cognition, or any outcome. That the body uses NAD+ is not a claim that a given product raises it usefully or changes anything you would notice. Those are clinical questions, and a supplier is the wrong party to answer them.