isomers glutathione serum Skincare Antioxidant Dermatology tested Glutathione Antioxidant Serum – Isomers
Description
For a quick summary, see this quote from one study : RESULTS: As one of the most powerful antioxidants in the skin, vitamin C has been shown to protect against photoaging, ultraviolet-induced immunosuppression, and photocarcinogenesis

No water-based ingredients that might spoil and no preservatives needed

Avoid adding more than couple as it may cause skin irritation
I try to add it to most of my oil-based formulations

You can add couple drops of essential oils to have some scent
I like to use this face serum at night
