Indeed, it is the decline in GSH levels that has been associated with many chronic and age-related conditions, as well as the aging process itself
Once you've established a stable protocol with GHK-CU alone, you can systematically reintroduce other compounds
Briefly, sodium bicarbonate, glucose, sodium pyruvate, and all 20 amino acids (except cystine and serine), biotin (B4639, Sigma), and vitamin B12 (V6629, Sigma) were added to the DMEM medium (#D9800-28, USBiological, Salem, MA) to match standard IMDM, supplement with 15% human AB serum and 15% dialyzed FBS (#SH300790340, Cytiva Hyclone), along with 10 ng/mL interleukin-3, 50 ng/mL stem cell factor and 2IU/mL erythropoietin
You should just put a few drops on your face and gently rub it in, usually once or twice a day