NAD+ (nicotinamide adenine dinucleotide) is having a longevity moment. Supplement aisles are full of NMN, NR, and oral NAD+ products promising cellular energy and anti-aging benefits. Most of them don’t work the way you’d expect — and the version that actually moves your blood NAD+ levels meaningfully is the injection nobody talks about.
This post is about injectable NAD+: what it does, how to dose it, and why it produces effects that oral forms can’t replicate.
What NAD+ actually does
NAD+ is a coenzyme. Roughly: it’s the molecular currency that powers metabolic reactions across every cell in your body. Mitochondria use it for energy production. Sirtuins (the longevity-associated proteins) use it as their primary substrate. Cells age in part because their NAD+ levels decline — by middle age, NAD+ levels are about half what they were at 20.
Boost NAD+ levels and you’d theoretically improve mitochondrial function, sirtuin activity, and DNA repair. Theoretically. The hard part is actually getting NAD+ into cells.
Why oral NAD+ supplementation underdelivers
NAD+ taken orally — whether as NAD+ itself, NMN (nicotinamide mononucleotide), or NR (nicotinamide riboside) — gets metabolized aggressively in the gut and liver. Some of it shows up as nicotinamide in your bloodstream. Some of it shows up as other metabolites. Very little of it makes it to peripheral cells as NAD+.
This isn’t a controversial position. It’s the consistent finding in pharmacokinetic studies: NMN bumps NAD+ levels in mouse studies that use injection; oral human studies show meaningful nicotinamide elevation but inconsistent NAD+ elevation in cells outside the liver.
Liposomal NAD+ products improve absorption somewhat but still don’t replicate the kinetics of an injection. The molecule wasn’t designed to be eaten.
Injectable NAD+ — actual delivery
Injectable NAD+ bypasses the gut and liver entirely. Subcutaneous and intramuscular routes deliver to systemic circulation with high bioavailability. IV NAD+ produces the largest, fastest peak (and is what longevity clinics charge $500–1500 per session for). Subq is the home-injection route — slower peak, longer functional window, no IV setup required.
The difference is meaningful. A single subq NAD+ dose produces a rapid increase in circulating NAD+ levels within an hour. Sustained dosing maintains elevated baseline. Oral protocols don’t approach these kinetics.
Dosing protocols
NAD+ vials commonly ship at 250 mg in dry powder form. A 250 mg vial reconstituted with 2 mL bacteriostatic water yields a 125 mg/mL working solution.
Common protocols:
- Daily low-dose: 20–50 mg subq per day, ongoing. This is the most practical home protocol — 20 mg is the confirmed starting point.
- Higher daily dose: 50–125 mg subq per day. Used by those who have established tolerance and want a stronger energy effect.
- Clinic-style IV push: 500–1500 mg over 2–3 hours, monthly. What longevity clinics charge $500–1,500 per session for. Largest acute effect; not a home protocol.
For home use, the daily low-dose subq protocol is the most sustainable. A 250 mg vial reconstituted with 2 mL BAC water (125 mg/mL) gives you 12+ days at 20 mg/day.
What to expect when you inject
NAD+ injection isn’t subtle. Most users feel something within 5–10 minutes:
- Facial flushing and warmth — vasodilation through nicotinamide pathways
- Mild head pressure — temporary, usually clears within an hour
- Brief nausea at higher doses or fast push rates — slow the injection and the nausea drops
- Increased mental clarity in the hour after injection — anecdotal but consistent across users
These effects are dose-dependent. Lower doses (20–50 mg) produce mild versions. Higher doses (250 mg+) produce the full intensity. New users should start at 20 mg to gauge response before escalating.
Stacking
NAD+ pairs naturally with peptides on the longevity side:
- NAD+ + Glycine + N-Acetylcysteine — the GlyNAC protocol that addresses glutathione synthesis
- NAD+ + MOTS-C — mitochondrial-targeted compound that complements NAD+’s mitochondrial effects
- NAD+ + Tesamorelin — for older lifters managing both visceral fat and mitochondrial decline
It does not meaningfully stack with the GLP-1 family or healing peptides (BPC-157, TB-500) — different mechanisms, no overlap, no interaction concerns either way.
The honest caveats
- The longevity benefits of elevated NAD+ are well-supported in animal models, but human longevity data is still accumulating. You’re betting on translation from mouse to human.
- NAD+ supplementation accelerates the activity of sirtuins, including in any existing tumor cells. Cancer history is a real concern, not a fig leaf.
- Subq injection sites for NAD+ can sting more than other peptides — the molecule is large and the solution is concentrated. Rotate sites.
- High doses can transiently raise heart rate and blood pressure during the injection window. Lower the dose if this is uncomfortable.
Where to buy
NovaPeptide sells injectable NAD+ in 250 mg vials with third-party COA on every batch. The packaging includes dry powder plus reconstitution instructions; you supply the bacteriostatic water. Use the BIOHACKMAXX code at checkout.
Bottom line
Oral NAD+ supplementation produces small, inconsistent increases in cellular NAD+. Injectable NAD+ produces large, reliable increases at a fraction of the cost per effective dose. If you want the NAD+ effect — and the longevity rationale appeals — injection is the only route that actually delivers what the marketing claims.
For the full reconstitution math on whatever vial size you’re working with, use the NAD+ reconstitution calculator. For the bigger picture on longevity peptides, the Peptide Guide covers the full stack.