Prices vary significantly between compounding pharmacies and vendors
Heres exactly how I ranked these glutathione contenders: Week 0 : Baseline photos (consistent lighting, no filter) Weeks 1-4 : Daily use (AM/PM), tracking glow + hydration Weeks 5-8 : Dark spot measurement (ImageJ software analysis) Weeks 9-12 : Long-term fading + skin barrier health Metrics : Melanin index reduction, user satisfaction, value/ Sample Size : 5 skin types (oily, dry, combo, sensitive, mature) Controls : Identical SPF/moisturizer routine across all tests Result : Only glutathione facewashes hitting 60%+ dark spot reduction made the top 10
Guaiacol peroxidase GPOX (EC 1.11.1.7) activity was measured in terms of increase in absorbance due to the formation of tetra-guaiacol at 470 nm and the enzyme activity was calculated as per extinction coefficient of its oxidation product, tetra-guaiacol = 26.6 mM 1 cm 1 83
Adding the second compound too early often leads to intense nausea and a forced step-down on one or both compounds
Photo Credit: Adam Fisher, Baldwin Publishing 30 mins These bite-sized treats offer a touch of sweetness with the added benefit of protein
