NRH (dihydronicotinamide riboside)

Tier 3 — weak evidence · NAD+ precursor · Longevity · Energy

A reduced form of nicotinamide riboside that, in preclinical work, raises tissue NAD+ more efficiently than NR or NMN. Human safety and pharmacokinetic data are emerging but efficacy RCTs on hard endpoints have not yet been published. Currently sold by a small number of premium longevity brands; significantly more expensive per gram than standard NR.

Dose: 25–100 mg/day; safety data in humans is limited