Azelaic Acid Versus Hydroquinone for Managing Patients With Melasma: Systematic Review and Meta-Analysis of Randomized Controlled Trials.
controlled
EVIDENCE COMPARISON
DirectionalAzelaic Acid
vs Cysteamine
for Pigmentation Reduction
Early or indirect evidence suggests cysteamine may reduce pigmentation 1.2 times more effectively than azelaic acid for improving skin tone, based on indirect comparison.
1.23x
Effect ratio
Cysteamine
Favored
2
Studies
Indirect
Comparison
ExploratoryEstimated endpointTone
Limits: Indirect comparison · Includes estimated measurement · Early-stage evidence tier
This is an indirect comparison — the two ingredients were not tested head-to-head in the same trial. The ratio is derived from separate studies against a common comparator.
How to read this claim
Kept public as exploratory because it indirect comparison; includes estimated measurement; early-stage evidence tier.
Some study-specific context may affect how broadly this comparison generalizes.