This concern appears to stem from glutathione's skin-brightening mechanism, which works by inhibiting melanin production through tyrosinase modulation a temporary, dose-dependent, and generally reversible effect, not an autoimmune depigmentation process like vitiligo
PubMed Sikiric, P., Seiwerth, S., Rucman, R., Turkovic, B., Rokotov, D.S., Brcic, L., Sever, M., Klicek, R., Radic, B., Drmic, D., Ilic, S., & Kolenc, D

Our introductory offer of 2875 for this 6-week programme includes the following: 1 x medical consultation with a doctor with ongoing monitoring and communication available throughout the programme 12 x Mitogive Glutathione IV drips that include Vitamin C (two per week please allow 30 45 minutes per drip) 3 x Multi-Vitamin IV drips (to be administered at first appointment as well as in Week 3 and Week 5 immediately after one of the 12 x Glutathione drips please allow 60 90 minutes for these appointments) 2 x Blood tests one just before the first therapy session begins to measure your intracellular glutathione saturation level and one before the start of your last infusion therapy session To ensure your safety and to maximise the effectiveness of your treatment we require all new patients to have a medical consultation prior to their first appointment
Vitamin C, or ascorbic acid, is a water-soluble vitamin that humans cannot produce on their own
doi: 10.3390/nu9060598 191 KwakJSKimJYPaekJELeeYJKimHRParkDSet al
GPX4-IN-1 has the potential for the research of cancer