At-home NR injections are here — the evidence behind them is two open-label pilot studies

Edited by Samael A. Tejada, Founder & Editor-in-Chief

NAD+ is the coenzyme mitochondria use to turn food into energy, and injectable NAD+ products are proliferating faster than their evidence. Niagen's launch is better documented than most — which makes it a useful test case for reading any injectable longevity claim: separate what the studies were designed to prove from what the marketing invites you to conclude.

What did the pilot studies actually test?

Safety and tolerability, first. In the two pilot studies (Nkrumah-Elie et al., 2026; Russ et al., 2026, on medRxiv), 39 generally healthy adults with elevated fatigue were randomized to 50 mg or 100 mg of Niagen by intramuscular or subcutaneous injection for three days under clinical supervision, then self-administered subcutaneous injections at home three times weekly for 90 days. The company reports the regimen was well tolerated with no unexpected adverse events, and that at-home self-injection was achievable under protocol conditions.

What about the fatigue, sleep and mitochondria claims?

Those come from the exploratory layer. Repeated injections were associated with improvements in fatigue, sleep impairment and quality of life on validated questionnaires, plus self-reported skin improvements; the studies also observed changes in markers of mitochondrial bioenergetics and reductions in several oxidative-stress markers. But everyone knew what they were injecting, there was no placebo group, the sample was 39 people, blood NAD+ levels remained stable over the 90 days rather than rising, and the papers are preprints, not peer-reviewed. Expectation effects alone can move fatigue and sleep scores — that is precisely what placebo controls exist to measure.

How should a reader price this launch?

As a feasibility and safety signal for a prescription product sold through telehealth — clinician-directed, LegitScript-certified platform, 503A dispensing — not as proof that injecting NR improves energy, sleep, skin or mitochondrial function in healthy people. The company states the caveat itself: these findings require confirmation in larger, placebo-controlled studies. Until one exists, the honest comparison is with oral NR, which has a far larger human literature, and with the free interventions that reliably move fatigue and sleep. Watchdog rule of thumb: when the study's own authors say 'exploratory,' believe them.

Where the evidence stands

• Established: NAD+ declines with age and is essential to mitochondrial energy production; NR is an NAD+ precursor with an extensive oral human literature. No published clinical studies have evaluated subcutaneous or intramuscular NAD+ injections themselves, per the company.
• Preliminary: In two open-label pilot studies in 39 adults (medRxiv preprints, announced Oct 22, 2026), injectable NR for 3 supervised days plus 90 days of at-home self-injection was well tolerated, blood NAD+ remained stable, and exploratory self-reported fatigue, sleep and skin measures and mitochondrial bioenergetics / oxidative-stress markers moved favorably.
• Absent: Placebo-controlled, peer-reviewed evidence that NR injections improve fatigue, sleep, skin, mitochondrial function or any clinical outcome — by the company's own statement, confirmation in larger controlled studies is still required.