Related blogpost: 5 Affordable & Popular Retinoid Serums Reviewed The Beginners Guide to Starting Retinoids All active ingredients and medications come with their own side effects and my preference for a topical lightening ingredients are L-ascorbic acid (vitamin C) and azelaic acid
Vitamin C also influences melanin production by downregulating tyrosinase, the same enzyme targeted by glutathione (systematic review)
US-based compounding pharmacies working with veterinarians are the safest source
Int Immunopharmacol 77:105969 Guo C, Huang T, Chen A, Chen X, Wang L, Shen F et al (2016) Glucagon-like peptide 1 improves insulin resistance in vitro through anti-inflammation of macrophages
The approach helps your body lose fat and increases energy levels
Andrew Huberman: If I recall, people younger than 40, you saw less of an effect