You might reduce bioavailability slightly if you inject everything in the same site at the same moment, but you're not causing harm
pmc.ncbi.nlm.nih.gov/articles/PMC9655540 (cites the singlet oxygen comparison
Duzel A, Vlainic J, Antunovic M, Malekinusic D, Vrdoljak B, Samara M, et al
Understanding Glutathione: The Master Antioxidant Before we dive into timing, we should define what glutathione actually is
10.1016/0006-2952(89)90048-8 Glazenburg EJ, Jekel-Halsema IM, Scholtens E, Baars AJ, Mulder GJ: Effects of variation in the dietary supply of cysteine and methionine on liver concentration of glutathione and "active sulfate" (PAPS) and serum levels of sulfate, cystine, methionine and taurine: relation to the metabolism of acetaminophen
If you have been keeping yourself updated with the latest trends in the skincare industry, you must have heard a growing buzz about glutathione