Dosing on NAD+: getting it right

A biohacker on r/Biohackers asked a plain question that gets buried under a lot of vague marketing copy: what were the actual doses of oral NADH used in the clinical trials, not the round numbers printed on a supplement label. Short answer: NAD dosing splits into three separate conversations depending on what you're actually taking, oral NADH, oral precursors like NR and NMN, or injectable NAD+, and each one has its own real dosing data. Mixing them up is where most people get their protocol wrong.

Oral NADH: the doses are small, and the absorption problem is real

Here's the thing that trips people up. NADH is the reduced form of NAD+, and it's the form your body actually shuttles electrons through inside mitochondria. That makes it sound like the obvious thing to swallow. The problem is that NADH is a large, fragile, charged molecule, and getting an intact dose of it across the gut wall and into your bloodstream in usable form is genuinely hard. The human studies that exist, mostly in chronic fatigue and some Parkinson's research, have used comparatively small oral doses, typically in the 5 to 20 mg per day range. That's not a typo. Compare that to NR or NMN trials, which run in the hundreds of milligrams, and you start to see why the community conversation has largely moved away from oral NADH and toward the precursor route instead.

I get asked about this a lot by people who bought a bottle of NADH tablets because the name sounds like the "active" version of NAD+ and assumed more direct must mean more effective. It doesn't work that way here. The bioavailability problem is the whole story, and it's why NR and NMN, which your cells convert into NAD+ through their own enzymatic machinery rather than relying on the intact molecule surviving digestion, have become the dominant oral strategy. If you're set on oral NADH specifically, stick to the studied 5 to 20 mg range and don't assume that scaling it up fixes the absorption issue, because it doesn't.

What the NR and NMN trials actually used

This is where the human data gets solid. A well-run dose-response trial found that NR raised blood NAD+ in a clean, dose-dependent way: +22%, +51%, and +142% at 100, 300, and 1000 mg respectively. That's a reproducible biochemical effect, not a maybe. On the NMN side, a trial in prediabetic postmenopausal women used 250 mg per day and saw improved muscle insulin sensitivity, which stands out as one of the more concrete functional results in the whole NAD+ literature. NR has also shown a real functional benefit outside metabolic health, improving six-minute walk distance in people with peripheral artery disease.

The practical range that comes out of this data is 300 to 1000 mg per day for NR, and 250 to 500 mg per day for NMN. Most people I talk to settle in the middle of those ranges rather than at the top. Take either one with food, in the morning, since some people report a wired, jittery feeling if they start too high too fast. That's not a dangerous reaction, it's your mitochondria suddenly having more raw material to work with, and it settles down once your body adjusts.

Why the decline happens in the first place, and injectable NAD+

NAD+ doesn't just fall with age because your body makes less of it. A big part of the story is consumption. CD38, an enzyme that ramps up with age and inflammation, was shown in a mouse knockout model to be the dominant driver of age-related NAD+ decline: eliminate CD38 in mice, and NAD+ stays at youthful levels regardless of age. That's animal data, but it lines up with the human review evidence on why sirtuin activity, DNA repair, and mitochondrial function all lean on adequate NAD+ supply as we get older, which is the mechanism the whole supplementation argument rests on. You can read the full mechanism breakdown in the NAD+ encyclopedia entry if you want the deeper version.

Injectable and IV NAD+ is a different tool from the oral precursors. It delivers the molecule directly instead of relying on your cells to convert a precursor, which is why clinics can push doses of 500 to 1000 mg over an hour or two by IV, or 50 to 250 mg by intramuscular or subcutaneous injection. The tradeoff is that going in fast can bring on infusion-related sensations, chest pressure, a racing heart, some GI upset, and slowing the infusion down is the standard fix clinics use. If you're building out a broader mitochondrial support stack, it's worth comparing how a compound like 5-Amino-1MQ approaches fatigue and energy through a different mechanism before deciding whether you need one lever or several.

A reasonable starting SubQ pattern that shows up repeatedly in practitioner protocols is 25 mg twice a week for the first two weeks, stepping up to 50 mg twice a week, then 100 mg twice a week by week five through eight, before settling into a maintenance dose around 100 mg weekly or every other week. Starting low and ramping slowly is what keeps people out of the uncomfortable acute-response territory that comes with jumping straight to a high dose.

Now the part my lawyer makes me say, and he's right to: the doses and schedules here are for educational and informational purposes only. These peptides are sold for research use only and are not FDA-approved drugs. This is not medical advice. Consult a qualified physician before beginning any protocol.

One more thing worth knowing if you're new to this space in general: peptides and NAD+ come with real questions about safety and sourcing, and it's worth reading through what the actual risk profile looks like before you build out a full stack rather than after.

If you take one thing away from this, let it be that "NAD dosing" isn't one number. It depends entirely on which of the three routes you're actually running, and the studies back each route with its own range. Matching the dose to the form you're taking beats guessing from whatever number you last saw on a forum post.