How to safely replace the Kligman formula: a step-by-step protocol If you’re using the Kligman formula and want to stop, you’ve probably already heard about the risks associated with hydroquinone: ochronosis, sensitization, dependence. Or you may have noticed that yo... Kligman's formula curcumin hydroquinone hyperpigmentation niacinamide retinol Mar 28, 2026