Study
NICE-PAD II: Nicotinamide Riboside to Improve Functioning in Peripheral Artery Disease (Phase 3)
Phase 3 trial will randomise 250 adults with peripheral artery disease to 1000 mg/day nicotinamide riboside or placebo for 6 months. Registered August 2026. Not yet recruiting, no results.
NICE-PAD II (NCT07782671) will randomise 250 adults aged 50 and older with peripheral artery disease to nicotinamide riboside or matching placebo for six months. The dose is 1000 mg per day, taken as two 250 mg capsules twice daily. Both the NR and the placebo capsules are manufactured by ChromaDex. Masking is quadruple: participant, care provider, investigator and outcomes assessor. The primary outcome is change in six-minute walk distance from baseline to six months. Secondary outcomes include the Walking Impairment Questionnaire distance score, PROMIS Mobility, calf muscle perfusion by MRI arterial spin labelling, plasma oxidised LDL, whole-blood NAD+ abundance, and six-minute walk distance four weeks after the intervention ends.
Mary McDermott at Northwestern University is the principal investigator. The National Institute on Aging funds the trial under grant 1R01AG090846, with the University of Chicago and the University of Minnesota as collaborators. The registry entry was first posted on 24 August 2026 with a status of not yet recruiting. Estimated start is December 2026 and estimated primary completion is December 2030.
This is the follow-up to the original NICE trial, published in Nature Communications in 2024, which randomised 90 people with peripheral artery disease to NR with or without resveratrol. That trial reported a between-group difference in six-minute walk distance of 17.6 metres favouring NR (+7.0 metres for NR versus -10.6 metres for placebo, 90% CI +1.8 to infinity). Among participants who took at least 75% of their pills, NR improved walk distance by 31.0 metres and NR plus resveratrol by 26.9 metres. The authors concluded that resveratrol added no benefit over NR alone, and called for a larger trial to confirm the finding. NICE-PAD II is that larger trial.
No results exist yet. A registry entry for a trial that has not begun recruiting carries no efficacy or safety evidence, so it cannot move our rating for nicotinamide riboside in either direction.
Phase 3, not yet recruiting. Estimated start December 2026, estimated primary completion December 2030. No results posted.
Registry entry only. No participants enrolled, no data, no results. This cannot support an efficacy claim for nicotinamide riboside. The predecessor NICE trial was small at 90 participants and reported a 17.6 metre walk-distance difference, an effect whose clinical meaningfulness is contested at that sample size, which is precisely why a 250-participant Phase 3 was funded. Note also that ChromaDex, which sells nicotinamide riboside commercially as Niagen, manufactures both the active capsules and the placebo used in this trial.
Noted and monitored. No change to the nicotinamide riboside rating.
A trial that has not started recruiting produces no evidence. Our rules require published human randomised trials or a meta-analysis before a rating moves, so a registration alone changes nothing. We list it because it is the largest nicotinamide riboside trial funded to date and its result will matter.
- Status change from not yet recruiting to recruiting, expected around December 2026
- Enrolment completion and any change to the 250-participant target
- Primary outcome posting: change in six-minute walk distance at 6 months
- Whole-blood NAD+ results, which would show whether the dose actually raised NAD+
- Any reported adverse events once dosing begins
Expected readout: December 2030 (estimated primary completion) · Decision recorded 2026-08-26
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2 encyclopedia entries reference this study.