Every study we read on this question

Trials in people (16)

• A 26-week NR trial in people with Werner syndrome: less artery stiffness, smaller ulcers
  Randomized trial2025Points to benefit
• A 4-week no-placebo NR trial in 8 people with leg artery disease reported gains
  Trial, not randomized20258 peoplePoints to benefit
• A 10-week NR trial in 20 adults with memory problems: no clear thinking gain
  Randomized trial202420 peopleNo difference
• 12-week NMN trial in 60 older adults: no clear gain on main stepping test
  Randomized trial202460 peopleNo difference
• A 60-day trial of NMN in 80 healthy middle-aged adults found longer walking distance
  Randomized trial202380 peoplePoints to benefit
• A 4-week NMN trial in 30 adults: lower weight and cholesterol, no strength change
  Randomized trial202330 peopleMixed
• A 24-week NMN trial in 14 older men: no clear grip or walking change
  Randomized trial202314 peopleNo difference
• A 12-week NMN trial in 108 older adults: all groups improved, afternoon NMN most
  Randomized trial2022108 peopleMixed
• A 32-day trial of niacin-related nutrients in 14 older adults: no clear muscle change
  Randomized trial202114 peopleNo difference
• A 6-week NR trial in 40 adults with lung disease: lower sputum inflammation marker
  Randomized trial202440 peoplePoints to benefit
• A 6-week NR trial in 22 healthy older adults lowered brain-disease blood markers
  Randomized trial202322 peoplePoints to benefit
• A 12-week NMN trial in 36 adults found no clear change in artery stiffness
  Randomized trial202336 peopleNo difference
• A trial of NR plus pterostilbene in 32 adults found no clear muscle gain
  Randomized trial202232 peopleNo difference
• A 10-week trial of NMN in women with prediabetes found better muscle insulin response
  Randomized trial2021Points to benefit
• A 3-week NR trial in 12 older men: less blood inflammation, muscle energy unchanged
  Randomized trial201912 peopleMixed
• A 6-week NR trial in healthy adults: well tolerated, higher NAD+ markers
  Randomized trial2018Points to benefit

Animal and cell (6)

• In mice, early NMN cut heart valve inflammation and calcium; late NMN worked less
  Animal study2026Points to benefit
• In mice, NaR raised NAD+ in many organs and eased kidney inflammation
  Animal study2025Points to benefit
• In mice, long-term NMN reduced frailty in both sexes; longer life only in females
  Animal study2024Mixed
• In mice, vitamin B3 protected eyes; 93% had no glaucoma at the top dose
  Animal study2017Points to benefit
• In mice, 12 months of NMN limited weight gain and improved several health measures
  Animal study2016Points to benefit
• In mice, NR rejuvenated muscle stem cells and lengthened life span
  Animal study2016Points to benefit

Reviews (7)

• Review of 113 studies of NAD+ boosters: higher blood markers, but health benefit unclear
  Systematic review2026Mixed
• Pooled review of 27 studies in 1,599 adults: NMN helped endurance, not strength
  Pooled review (meta-analysis)20261,599 peopleMixed
• Pooled review of 15 NMN trials found no extra side effects or liver changes
  Pooled review (meta-analysis)2026No difference
• Pooled review of 9 NMN trials, 412 people: faster walking and lower liver enzyme
  Pooled review (meta-analysis)2025412 peoplePoints to benefit
• Pooled review of 12 NMN trials found no clear blood sugar or fat change
  Pooled review (meta-analysis)2025513 peopleNo difference
• Pooled review of 8 NMN trials, 342 people, found no clear blood sugar benefit
  Pooled review (meta-analysis)2024342 peopleNo difference
• Review of 147 animal and human studies of NAD+ boosters found mixed results
  Systematic review2020Mixed