IRCT20140212016557N5 IRCT 2019-12-03 Shiraz University of Medical Sciences Comparison of the effect of cysteamine cream and hydroquinone cream in the treatment of acne pigmentation Comparison of the therapeutic efficacy of cysteamine 5% cream with Hydroquinon 4% cream in acne-induced postinflammatory hyperpigmentation patients 2019-04-06 anticipated 50 Complete https://irct.ir/trial/43792 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: The participants were randomized using permuted block randomization (size of each block: 4), in individual units, using random allocation software. The medications are in the similar tubes labeled by numbers of the patients, Blinding description: Despite of close similarity of medications tubes, the participants cannot be blind because of the different instructions for use. Principle investigator, the drug presentation staff, and care provider physician are also aware of the type pf drugs. But, data collectors and outcome assessors are not aware of the medication of each patient. 3 Acne-induced post-inflammatory hyperpigmentation. Intervention 1: Intervention group: Cysteamine 5% cream (Scentispharma, Switzerland) is applied once every night for 15 minutes for 4 months on the face skin. Intervention 2: Control group: Hydroquinone 4% cream which is made by dissolution of 2 grams powder of hydroquinone (Merck, Germany) and 1.5 grams ascorbic acid powder (Merck, Germany) in 50 grams of vanishing cream (Minoo, Iran) is applied once every night overnight for 4 months on the face skin. No - There is not a plan to make this available Justification or reason for not sharing IPD is There is no further information.