The short version.
NAD+ is a central cofactor in oxidative phosphorylation — the process your mitochondria use to convert food into ATP. It's also the substrate for sirtuins (SIRT1-7), PARPs (DNA-repair enzymes), and CD38. When you're fatigued at a cellular level, the NAD+/NADH ratio is part of what's actually broken.
What's well-established: tissue NAD+ levels decline with age. PARP and CD38 activity rise, consuming NAD+. Mitochondrial dysfunction in older adults correlates with lower NAD+ pools. What's less established: that exogenous NAD+ — whether infused, injected subcutaneously, or supplemented as a precursor — produces the subjective "energy" people are looking for at scale, and at what dose.
What the literature actually says.
Most rigorous human data is on NAD+ precursors (nicotinamide riboside, NMN). Several trials have shown these raise whole-blood NAD+ levels, but translation to functional outcomes — fatigue, exercise performance, cognition — has been inconsistent. Effect sizes are usually modest, and patient-reported energy is notoriously difficult to study.
Direct NAD+ administration via IV or subcutaneous injection has less rigorous trial data. The clinical user experience reports — "I felt different within a day" — exist, but they're confounded by setting (an IV clinic with hydration is a strong placebo), individual baseline, and the absence of blinded controls.
The honest framing: NAD+ is a real cofactor in real metabolic processes that genuinely decline with age. Whether the typical patient feels a meaningful energy effect is more variable than the category's marketing implies, and the strongest case is in older adults with documented metabolic or mitochondrial issues.
NAD+ is real biochemistry. The question isn't whether it does something — it's whether you'll feel what it does.
Why oversight matters.
The internet sells almost any peptide as research chemicals — vials with disclaimers, no prescription, no provider, no follow-up. The risk isn't theoretical. Sterility, peptide identity, peptide content, and contamination all vary widely between gray-market vendors. The FDA has been explicit that compounded drugs aren't FDA-approved, and that research-only labels don't protect consumers when products end up in human use.
Oversight isn't a bureaucratic checkbox. It's a U.S.-licensed prescriber who reviews your history before prescribing, a 503A compounding pharmacy that sources active pharmaceutical ingredient and prepares the medication under USP 797 sterile standards, and a follow-up cadence that lets someone catch a problem before it becomes a worse one.
How Boswell handles this.
Boswell pairs you with a U.S.-licensed physician for the intake. They review your goals, medications, history, and any contraindications before prescribing. If a protocol isn't appropriate, you don't get it. If it is, the prescription goes to a 503A compounding pharmacy that prepares the medication under sterile compounding standards, labels it for you specifically, and ships it directly.
Refills aren't automatic — they involve a check-in. The point isn't to gate access; it's to keep someone clinical in the loop while you're on therapy. How Boswell works →
Questions worth asking your provider.
- What's my likely baseline — sleep, thyroid, B12, ferritin, hormones — before I add NAD+?
- If I don't feel a difference, how long do we run it before stopping?
- Does a precursor (NR, NMN) make more sense than direct NAD+ for my use case?
- Should I be on an intermittent or continuous schedule?
- What labs would you reassess after 8-12 weeks?
Sources