Glycine and N-acetylcysteine (GlyNAC) supplementation in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, insulin resistance, endothelial dysfunction, genotoxicity, muscle strength, and cognition: Results of a pilot clinical trial

Researchers gave a combination of glycine and N-acetylcysteine, called GlyNAC, to 24 older adults for 24 weeks. They compared some measurements with 8 younger adults and checked the older adults again after they stopped taking it. The older adults showed higher glutathione, a substance that helps protect cells, along with improvements in blood sugar control, inflammation, muscle strength, and thinking tests. The study also reported improvements in cell energy production and blood-vessel function. However, it was a small pilot study without a strong placebo comparison, so the changes may not have been caused entirely by GlyNAC.

What this means for you: This is not strong enough evidence to buy GlyNAC for general anti-aging benefits. It is reasonable to wait for larger, well-controlled studies, especially because supplements can have side effects and costs.