Khellin has been used as an herbal folk medicine, with use in the Mediterranean dating back to Ancient Egypt, to treat a variety of maladies including: renal colic, kidney stones, coronary disease, bronchial asthma, vitiligo, and psoriasis.

Once purified, khellin exists as colorless, odorless, bitter-tasting needle-shaped crystals[2] and is classified as a gamma-pyrone, a furanochromone derivative.

Unwanted side effects include dizziness, reversible cholestatic jaundice, pseudoallergic reaction, and elevated levels of liver enzymes (transaminases and gamma-glutamyltransferase).

When khellin is applied topically in combination with UVA light, it is able to stimulate melanocytes (cells that produce melanin) in hair follicles for successful treatment of vitiligo.

[6] When taken systemically, khellin induces elevated liver enzyme levels and broad photosensitivity; however, topical application reduces these side effects.

While khellin treatment in conjunction with UV therapy is successful, accelerated photoaging and increased risk of skin cancer is another concern.