The Science

A plain-English guide to the peer-reviewed evidence behind everything we sell. Written by Mark Howard, medically reviewed by Dr. Larry Tafford, MD — General Practitioner (GP). Last reviewed: 10 April 2026.

NMN & NAD+

Nicotinamide mononucleotide (NMN) is a direct metabolic precursor to NAD+ — nicotinamide adenine dinucleotide — a coenzyme present in every cell in the body. NAD+ sits at the centre of three tightly linked systems: mitochondrial energy production, PARP-mediated DNA repair, and sirtuin-driven gene regulation. Human tissue NAD+ concentrations fall roughly 50% between your 20s and your 60s. That decline tracks with the loss of cellular resilience that defines biological aging.

NMN supplementation has been shown to raise NAD+ levels in human trials. Published work from Keio University (Igarashi et al. 2022), Washington University (Yoshino et al. 2021, Science), and independent groups (Yi et al. 2022) have documented NAD+ elevation and functional improvements — insulin sensitivity, gait speed, muscle strength — at doses between 250 mg and 1,200 mg per day. Safety data through 12 weeks at the 1,200 mg/day upper bound has been published (Park et al. 2023).

Resveratrol & sirtuin activation

Resveratrol is a polyphenol originally isolated from grape skin and Japanese knotweed. In research, trans-resveratrol is the active isomer — it directly activates SIRT1, a member of the sirtuin family of NAD+-dependent enzymes that regulate gene expression and stress response. The pairing with NMN is biochemically rational: NMN raises the NAD+ substrate, resveratrol activates the sirtuin enzymes that consume it. One without the other leaves the pathway half-engaged.

Algae-derived Omega-3 DHA

DHA is the dominant omega-3 fatty acid in the human brain and retina. The European Food Safety Authority (EFSA) has authorised the health claim that DHA intake contributes to the maintenance of normal brain function and normal vision at an intake of 250 mg/day. That is the foundation of our Omega-3 formulation. We source DHA directly from marine algae rather than fish. Fish themselves acquire DHA by eating algae — sourcing at the algae step bypasses ocean-bioaccumulated heavy metals, PCBs and dioxins, and produces a vegan product with a higher DHA-to-EPA ratio than typical fish oil.

Key references

Song Q, et al. Nicotinamide mononucleotide (NMN) supplementation and NAD+ metabolism — systematic review. Frontiers in Aging, 2023. PMC10165139.
Igarashi M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. Nature npj Aging, 2022.
Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science, 2021.
Yi L, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience, 2022.
Park JH, et al. Safety of nicotinamide mononucleotide (NMN) supplementation up to 1,200 mg/day. Scientific Reports, 2023.
EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on the substantiation of a health claim related to DHA and contribution to normal brain function. EFSA Journal.
UK Food Standards Agency. Novel foods guidance. food.gov.uk.
EFSA. Public consultation PC-1537 — β-NMN as a novel food. Opened July 2025.

All sources cited here are peer-reviewed primary research or official regulatory documents. If you would like a reference we did not cite, or believe one of our summaries is inaccurate, email hello@humannutrients.com. See our editorial & medical review policy.