Apparently, glutathione remains intact and then steeply declines starting around age 45.
I’ve heard Dr. Stanfield and Physionic both say they didn’t think it was worth taking before age 45.
The average age of people in the GlyNAC studies was 71 years old and the dosages were close to 10g of each.
In a personal level, I’ve been supplementing both Glycine (4-5g from Collagen and whatever else) and NAC (1200-2400mg) for years and I’m in my late 30s.
I’m conflicted. Any opinions?
Why do you think you need it?
I started doing the GlyNac thing 3 years ago, 65 at the time. Not sure if it has actually moved any of my markers and it’s not inexpensive to do at the clinical doses but I’m OK with not “feeling” a benefit.
I doubt there is much benefit to younger people.
A 2023 randomized clinical trial found that supplementing NAC + Glycine for 16 weeks in older adults improved glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, physical function, and 7 hallmarks of aging (PMID: 35975308)
The authors claimed: “Only NAC + Glycine supplementation in older adults resulted in significantly improved (a) glutathione concentrations by 121% after 2 weeks, and by 164% after 16 weeks to levels not different from younger adults”
NAC + Glycine was found to improve glutathione deficiencies; lower oxidative stress; and improve mitochondrial function, inflammation, insulin resistance, endothelial dysfunction, genotoxicity, and multiple aging hallmarks (PMID: 34587244)
While at the same time improving muscle strength, exercise capacity, cognition, and body composition (PMID: 34587244)
In mice, a 2022 study found NAC + Glycine extended lifespan by 24%: (PMID: 35268089) They (1) lived 24% longer than control mice; (2) improved impaired glutathione synthesis, oxidative stress, mitochondrial dysfunction, abnormal mitophagy and nutrient-sensing, and genomic damage.
With age you see a decrease in glutathione and correcting glutathione deficiency with NAC + Glycine improves health status and hallmarks of aging (PMID: 21795440)
Both glycine and NAC are precursors to glutathione, which is an important antioxidant in the body, Glutathione has neuro-, hepato-, and cardioprotective effects.
The doses in these clinical trials have been quite large: 100 mg/kg of glycine and 98 mg/kg of NAC. Doses of 2.4 g/day each haven’t been seen to be effective in raising glutathione, whereas 4.8 and 7.2 g/day have raised glutathione.
Whether or not GlyNAC has any effects in younger adults without comorbidities is not clear and the effects would probably not be that significant. However, GlyNAC appears to be quite effective for situations of chronic high inflammation and accelerated aging i.e. comorbidities.
I don’t know whether I do or not. I’ve been kind of taking NAC/NAC-ET as an insurance policy since it’s not easy to check glutathione levels. However, the older individuals needed over 7g to get the benefits, so I wonder if “younger” folks need less or if it’s just a total waste before a certain age (45).