Editorial policy

Last updated 4 September 2026.

How providers get on the site

A provider is listed because it sells NAD+ to consumers in the United States and publishes enough about the price to be worth comparing. It is not listed because it pays us, and it is not left off because it does not — the roster contains providers that pay this site nothing, and the disclosure page names them and counts them.

How prices are read

Every price is read by hand from a page the seller publishes, and the page and the date are recorded with it. Nothing is scraped out of free text and nothing is inferred from a range. Where a seller states a price without a dose, or a dose without a price, the row is left out of the ranking rather than estimated into it.

A price is never printed without its qualifier. “$189” on its own is not a fact about anything; “$189 per month, month-to-month, read 2 September 2026” is. A price with no reading date is wrong about half the time, which is why every figure here carries one.

How the arithmetic is labelled

Cost per milligram is a division this site performs. So, usually, is the milligram total itself: most sellers print a dose and a schedule but never multiply them out. Both are labelled as ours on the line where they appear, and the division is printed underneath the result so it can be checked. Where a seller publishes its own equivalence — “works out at $X a month” — that is quoted separately as theirs, and where their figure and ours disagree, both are shown and the disagreement is stated.

What we will not say

We will not name a cheapest provider off a parsed price. We will not print a per-month figure a seller does not state as though the seller stated it. We will not call a route expensive, because expensive is a judgment and the number is the finding. And we will not describe anything on this site as clinically reviewed, because it is not.

How often it is re-checked

Prices are re-read on a schedule and the date on the page is the date of the last successful read, not the date of the last edit to the sentence around it. When a re-read changes a number, the change is logged on the corrections page.

What a commercial relationship changes

Nothing about position, nothing about wording, nothing about whether a competitor appears. It changes exactly one thing on the page: the line under the button that says whether we are paid. The ranked table is ordered by arithmetic, which is not for sale.