guide · six things sold as one
NAD
Your cells use NAD to turn food into energy and to repair themselves, and you make less of it as you get older. That much is real, and it is why the shelves filled up. What follows is what each option actually is, and where the research is strong enough that we would say so.
What it does for you
NAD is a small helper molecule, and there is some in every cell you have. Its main job is passing energy along the line that turns your breakfast into something your body can spend. It also lends a hand with DNA repair.
Levels do drop with age. The interesting question — the one the research is still working on — is whether topping it back up makes you feel any different. For some of these options there is real evidence. For others, honestly, not yet.
What is actually in the bottle
Here is the part that trips most people up, and it is worth thirty seconds. NAD itself does not survive the trip through your stomach, so nothing on the shelf is really NAD — even when the label says so in big letters.
What you are buying is a raw material your body builds NAD from. Six of them turn up on labels, they cost wildly different amounts, and they are not interchangeable — a study of one tells you nothing about the others. So it is worth knowing which one you have.
The one the longevity market was built on, and the one we have the most to say about — we rate it for afternoon energy crashes and for chronic fatigue. Both of those ratings rest on a single study each, so treat them as a promising start rather than a settled case.
Typical amounts: 250–500 mg a day in the research
The original, and by far the cheapest — it is already in your multivitamin. It has the longest research history of anything here, but that history is about cholesterol and blood pressure rather than energy or ageing, and the doses involved are much higher than a B-complex carries.
Typical amounts: 500–2,000 mg in the blood-pressure trials; a B-complex has 50–100 mg
Probably the one you have seen advertised most, and the most studied of the newer options. We have not reviewed it yet, so we are not going to tell you either way — that is a gap in our work, not a verdict on the ingredient.
Typical amounts: 250–300 mg a day on most labels
The gentler face of vitamin B3 — it does not cause the hot, prickly flush that plain niacin can. You will meet it far more often in a face cream than in a capsule. We have not reviewed it yet.
Typical amounts: 500 mg capsules are common
This is the molecule itself, in tablets designed to survive the stomach. Whether enough of it actually gets through is the open question, and it is the reason most products use one of the options above instead. Not reviewed by us.
Typical amounts: 5–20 mg a day on labels
Worth knowing about because your body can build NAD from scratch out of this ordinary amino acid — it is in turkey, eggs, oats and cheese. Nobody markets it for NAD, which tells you something about where the margins are. Not reviewed by us.
If you are choosing one
A few things we would want a friend to know before spending anything.
- Check the vitamin B3 you already own first. It is in nearly every multivitamin and B-complex, it costs almost nothing, and if you are low, that is the cheapest thing to fix.
- Do not let the blood-pressure evidence sell you an energy product. Niacin’s strongest result is for blood pressure, at doses ten to twenty times what a B-complex holds. It is a real finding about a different question, and it gets borrowed a lot.
- Price is not evidence. The most expensive options here are the newest, which mostly means they have been studied least — not most.
- Where we say nothing, we mean nothing. Four of the six above are gaps in our research rather than judgements against them. We would rather show you the gap than fill it with an opinion.
Already have one at home?
The amount on the label is what decides whether any of this applies to your bottle. Type the name in and we will read the panel against the research for you.
Check a bottle →What about the IV drips?
Clinics offer NAD straight into a vein, which does get around the digestion problem. It is a medical procedure rather than a supplement, with a very different price tag, so we cover it separately.
NAD+ Intravenous Therapy →Every rating here comes from the published research behind that specific claim — how we grade the evidence. Typical amounts are what labels and studies commonly use, not a recommendation. Talk to a doctor or pharmacist before starting anything new, especially if you take prescription medicines.