Mequinol (4-hydroxyanisole) is a drug that is used in combination with the drug tretinoin to treat age spots (solar lentigines), vitiligo and other discolorations. Mequinol/tretinoin is applied directly to the age spots without touching the surrounding skin at least twice a day. The solution is easily washed off, so shower before treatment.
Some of the side effects of mequinol are redness, burning, stinging, itching or shedding. It should not be applied near the eyes, mouth or nose. It should also not be used by pregnant women.
Mequinol/tretinoin should not be used in combination with drugs that sensitize the skin to sunlight or bright indoor light such as antibiotics.