Does the combination of glycine and NAC (GlyNAC) help against aging?

GlyNAC combines two amino acids: glycine and NAC (N-acetylcysteine). Together they support the production of glutathione, one of the most powerful antioxidants in your body. As you age, you produce less glutathione. This is associated with more cellular damage, poorer energy production in your cells and a greater risk of age-related complaints. Notably, healthy older adults who are in excellent shape have higher glutathione levels than comparable peers of the same age¹.

The strongest study in humans is a placebo-controlled trial with 24 older participants lasting 16 weeks². At the end, the GlyNAC group showed less oxidative damage, better functioning fat metabolism in the cells and improved physical performance: faster walking speed, greater muscle strength and more endurance. Inflammation markers, insulin resistance and blood vessel function also improved compared to placebo. Encouraging, but with 24 people these are still early results.

A smaller pilot study without a control group followed 8 participants for 24 weeks³. It reported improvements in memory and concentration, body composition and reduced DNA damage. Notably, the benefits diminished once participants stopped for 12 weeks. Without a control group you cannot rule out other factors, so this evidence is limited.

In both studies GlyNAC was well tolerated and no serious side effects occurred^2,3. That is reassuring, although the groups were small and the durations short.

GlyNAC has also been studied in HIV, where a similar glutathione deficiency occurs. However, that research is too methodologically diverse for firm conclusions⁴. The same applies to ageing: wait for larger and longer studies before attaching high expectations to it.