Glutathione does have some skin-lightening effects—mainly by reducing melanin production—but the evidence is thin. Only three small controlled studies support it working at all, and they tested topical and oral forms, not the trendy IV injections. The research shows we still don't know how long results last, if they stick around, or what the best dose is.

This was a literature review examining glutathione's role in skin lightening, looking at its chemistry, how it works in the body, and what clinical evidence exists to back up the hype.

Funding not disclosed in abstract