Does the combination of glycine and NAC (GlyNAC) help against aging?
GlyNAC shows promising results in a small human study on oxidative stress, muscle function and inflammation, but the evidence is still too preliminary for strong recommendations.
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 occurred2,3. 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.
Based on one controlled study in humans (n=24, PMID 35975308), one pilot study without a control group (n=8, PMID 33783984), one review article on glutathione and ageing (PMID 37683986) and one review article on HIV (PMID 41754089). No meta-analyses available. The total number of participants in controlled research is small.
Does NAD+ supplementation slow biological ageing?
NAD+ supplements raise your NAD+ levels in the blood, but whether that also means you age biologically more slowly has not been demonstrated in humans at this time. The question is interesting, but firm conclusions cannot yet be drawn; keep an eye on future large-scale research if you are seriously considering this.
At what age does taking NAD+ supplements make sense?
There is no established age at which NAD+ supplementation becomes worthwhile; studies focus on middle-aged and older adults, but a measurable functional benefit in humans has not yet been demonstrated. Anyone considering starting does so on the most informed basis after middle age, with realistic expectations.
Does taking resveratrol make sense as an anti-ageing strategy?
For humans there is no convincing evidence that resveratrol supplements do anything against ageing; the animal research is interesting but has not yet translated into clinical practice, so hold off on supplements until better human data are available.
Does quercetin work against ageing and inflammation?
Quercetin shows promising signals in the laboratory and in animals, but in humans there is not yet solid evidence. Taking supplements on the basis of this early-stage research gets too far ahead of the science.
Do GLP-1 medications (such as Ozempic) help you age more healthily?
For people with cardiovascular disease, kidney disease, or fatty liver disease, GLP-1 medications offer proven benefits that are also relevant at older ages. As an anti-ageing intervention in healthy people, their use is not yet supported by evidence.
What are the effects if you take NAD every day?
Taking 600-900 mg of a NAD supplement per day raises your NAD levels and provides some benefit for endurance, but long-term safety has not yet been properly studied.