The efficacy and tolerability of 5‐aminolevulinic acid 5% thermosetting gel photodynamic therapy (<scp>PDT</scp>) in the treatment of mild‐to‐moderate acne vulgaris. A two‐center, prospective assessor‐blinded, proof‐of‐concept study

This proof-of-concept study supports the efficacy of 5% ALA thermosetting gel red-light PDT in inflammatory acne of the face with a relevant clinical improvement of inflammatory lesions with a very good tolerability profile. Clinical improvement was maintained in the medium term (Trial Registration Number: ISRCTN66066651).