NR Glutathione

This is one of the more well-established findings in human NR research. In an 8-week randomized, double-blind, placebo-controlled trial of 120 healthy adults ages 60-80, NAD+ levels in whole blood increased by approximately 40% at the standard dose and approximately 90% at double dose after 4 weeks, with the increase sustained through the full 8-week trial. A separate pharmacokinetic study in healthy volunteers found NAD+ levels increased by 100% at steady state after dose escalation to 1000 mg twice daily. The NAD+-raising effect is consistently reproduced across studies.

In a 6-month randomized trial of 90 people with peripheral artery disease, NR supplementation improved 6-minute walk distance by 7 meters versus a 10.6-meter decline in the placebo group, and among those who took at least 75% of their doses, NR improved walk distance by 31 meters. That's a real functional outcome tied to NAD+ elevation, not just a biomarker shift — though it's worth noting this trial was in a specific patient population (PAD), not healthy adults.

 Yes, safety is consistently reported across studies. The 120-person trial reported no serious adverse events, and the pharmacokinetic study noted oral NR was well tolerated with no adverse events even at doses up to 1000 mg twice daily.

Trials show a benefit: one study found that oral glutathione supplementation in healthy individuals led to a significant increase in blood glutathione, and in diabetic patients, six months of 500 mg daily supplementation was associated with a significant increase in blood glutathione and a significant decrease in an oxidative damage marker within three months.

 Based on the research, yes. A recent crossover trial comparing formulations found that enhanced-delivery versions increased whole-blood glutathione more than standard glutathione, with one specialized formulation producing significantly greater absorption over 24 hours than the others tested. This is a meaningful consideration for anyone evaluating glutathione supplements — the raw ingredient matters less than how it's delivered.

Human trials show measurable NAD+ increases within a fairly short window — one trial detected increased NAD+ within 5 weeks, and the 120-person trial saw significant increases by the 4-week mark that held through 8 weeks.