Efficacy of metformin vs. doxycycline in treating acne vulgaris: An assessor-blinded, add-on, randomized, controlled clinical trial.

This trial indicates equal efficacy of doxycycline and metformin in reducing acne vulgaris severity, with doxycycline performing better in reducing lesions of the inflammatory type. Confirmatory or equivalence clinical trials should be performed to confirm our results.