Supplementing glycine and N-acetylcysteine (GlyNAC) in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, physical function, and aging hallmarks: A randomised clinical trial
Introduction
Ageing is characterised by a gradual decline in cellular function, antioxidant defences, and mitochondrial function, contributing to reduced physical performance and increased disease risk. One key factor is glutathione depletion, which leaves cells vulnerable to oxidative stress and inflammation.
This randomised, double-blind, placebo-controlled trial investigated whether supplementing with GlyNAC (glycine and N-acetylcysteine) could restore glutathione levels and improve key markers of ageing.
The results? GlyNAC supplementation led to significant improvements in oxidative stress, mitochondrial function, and physical performance – changes that could play a major role in supporting healthy ageing.
What did the study examine?
Researchers conducted a 16-week clinical trial to assess the impact of GlyNAC supplementation on glutathione levels, metabolic health, and physical function.
The participants were divided as follows:
- 24 older adults (ages 61–80) randomly assigned to receive GlyNAC or placebo.
- 12 younger adults (ages 21–40) taking GlyNAC, serving as a comparison group.
The study measured oxidative stress markers, mitochondrial function, inflammation, and physical performance before and after supplementation.
Findings
Cellular and metabolic health
- Glutathione levels increased by 164%, restoring them to levels comparable to younger adults.
- Oxidative stress markers dropped by over 70%, indicating reduced cellular damage.
- Mitochondrial function improved by 78%, indicating improved energy metabolism.
Inflammation and systemic health
- IL-6, a key pro-inflammatory cytokine, decreased by 78%.
- TNFα levels dropped by 54%, lowering systemic inflammation.
Physical performance and strength
- Gait speed increased, an important clinical measure of mobility and independence.
- Muscle strength improved in both upper and lower body.
- Stamina increased, with better performance in the 6-minute walk test.
No significant improvements were observed in the placebo group.
Why does this matter?
Ageing is inevitable, but optimising cellular health can substantially impact quality of life. By replenishing glutathione, improving mitochondrial function, and reducing inflammation, GlyNAC supplementation may help address ageing-related deterioration, from muscle strength and mobility to metabolic health.
GlyNAC was well-tolerated, with no adverse effects reported in the trial, making it a promising option for healthy ageing support.
You'll find the full study here.
