What dosage of glutathione is recommended for skin lightening?

Thanks for your query. There could be hormonal imbalance which can cause skin darkening. You can show to a physician and get your hormones tested. Yes the ethnicity also plays a role in skin darkening. Hope it helps.All The Best

Although it's difficult to see from the photo provided, you may benefit from eye creams with blends of kojic acid, vitamin K and/or hydroquinone.  This will definitely give some remedy to the pigmentation.

Thank you for asking about your belly button darkening after your tummy tuck.First, try using 100% shea butter or cocoa butter on the belly button. Then, keep using that but also ask your surgeon to prescribe 4% hydroquinone.AND keep the belly button out fo the sun -If you expose darkened skin ...