The same body of research also found that higher doses of GHK-Cu can produce skin irritation, and that copper in general is highly toxic, which is why formulation and concentration matter considerably in any experimental design involving this compound
Outliers were removed from control data after identification with ROUT Q = 0.5% (number of outliers removed: NAD + /NADH ratio n = 2, NADP + /NADPH ratio n = 11 and GSH/SSG ratio n = 6, no outliers were identified for individual metabolites)
When combined with metformin, the results can be even stronger, leading to better glucose control, lower androgen levels, and improved menstrual regularity
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The more plausible worry is indirect: if oral glutathione alters the gastric micro-environment (for instance, by binding trace minerals in the gut lumen), it could marginally shift the pool of free cations available to complex with alendronate, making absorption even less predictable