NAD+

Overview

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell, where it shuttles electrons for energy metabolism and activates repair enzymes such as sirtuins and PARPs. Tissue levels decline with age, and that observation underpins the marketing of injectable NAD+ for energy, focus, recovery, and longevity. It is worth stating plainly that NAD+ is a naturally occurring metabolic cofactor, not a peptide, and injectable formulations are largely unregulated and used off-label.

Evidence Quality

The biology of NAD+ is well established, and preclinical studies consistently link higher NAD+ to better mitochondrial and metabolic function. Human evidence is thinner: most randomized trials studied oral precursors such as nicotinamide riboside and NMN rather than injected NAD+, and the trials that do exist for IV NAD+ are small and short. Overall the human data are mixed and early, which places practical confidence in the C range.

What the Research Shows

Controlled and open-label studies suggest NAD+ precursors reliably raise blood NAD+ levels, and small trials have explored IV NAD+ in addiction recovery, chronic fatigue, and general wellness with modest or preliminary results. A recent real-world pilot comparing IV NAD+ with nicotinamide riboside found NAD+ infusions were poorly tolerated, producing cramping, nausea, and cardiovascular symptoms that required very slow infusion. Claims that injected NAD+ slows aging in otherwise healthy adults remain plausible but unproven.

Dosage Notes

Community subcutaneous dosing typically runs 50 to 100 mg per day, often started around 20 to 25 mg to gauge the sting and titrated upward. Clinic IV protocols use much larger amounts, commonly 250 to 1000 mg per session infused slowly over one to several hours. Across every route the consistent theme is speed: delivering NAD+ slowly is the single most effective way to limit flushing, cramping, and nausea.

Who Should Be Cautious

People with heart-rhythm problems, uncontrolled blood pressure, pregnancy, or serious chronic illness should not self-inject without medical supervision. Anyone new to NAD+ should assume the first doses will sting and should start low. Because injectable NAD+ is unregulated, product purity and sterility vary by source.

Availability

NAD+ is sold by compounding pharmacies and research suppliers as a lyophilized powder that must be reconstituted with bacteriostatic water before use. It is not an FDA-approved drug for longevity or energy, and quality depends heavily on the supplier.

Bottom Line

NAD+ has compelling cell biology and enthusiastic user reports but only limited, mixed human evidence for its injectable longevity and energy claims. Used at conservative subcutaneous doses and injected slowly, it is generally reported as tolerable aside from a notable sting; larger IV doses belong in a supervised clinical setting.