How it works
NAD+ is a coenzyme central to energy metabolism and to the sirtuin and PARP enzyme families involved in DNA repair. Tissue levels decline with age, which is the observation the entire category is built on.
The step that has not been demonstrated is the one that matters. Raising a biomarker that declines with age is not the same as reversing anything that decline causes, and that is exactly the inference the marketing asks you to make.
What the evidence shows
Oral precursors, nicotinamide riboside in particular, reliably raise blood NAD+ in small human trials. Those trials measured NAD+ levels. They did not show improvements in energy, cognition, ageing markers or any clinical outcome. No adequately powered outcome trial has been completed.
Typical dosing
No established therapeutic dose, because no indication is approved. IV clinic protocols vary widely and are not derived from trials.
Reported side effects
Rapid IV infusion commonly produces flushing, nausea, chest tightness and cramping during administration, which is why infusions are given slowly over hours. These are infusion reactions rather than effects of the molecule at rest.
Labelled warnings and contraindications
- IV infusion clinics operate with limited regulatory oversight. The risks that attach are the ordinary risks of intravenous access, including infection and extravasation, rather than anything specific to NAD+.
- FDA ruled in 2022 that NMN is excluded from the dietary supplement definition because it had previously been investigated as a drug. Its status as a supplement ingredient is contested. Nicotinamide riboside is not affected by that ruling.
- No approved indication means no labelled contraindication set. Absence of warnings is absence of review.
Legal status and sourcing
NAD+ is not an approved drug for any indication. Injectable and IV preparations are compounded or sold outside the approval framework entirely.
Oral nicotinamide riboside is marketed as a dietary supplement. NMN's supplement status is disputed following the 2022 FDA position.
What it costs
IV clinic pricing varies by market and is not reproduced here.
How confident anyone can be
Low for the claims, reasonable for the biochemistry. The decline is real, the precursors do work as precursors, and the outcome evidence simply is not there yet.
This is the clearest example in the library of accurate underlying science being used to sell a conclusion the science has not reached.