Efficacy and safety of retinaldehyde 0.1% and 0.05% creams used to treat photoaged skin: A randomized double-blind controlled trial

Background: Although topical retinoic acid effectively restores photoaged skin, the associated irritation limits the utility of the material. Retinaldehyde (RAL) is the natural precursor of retinoic acid and can also be used to treat photoaged skin; the safety profile is good. Aims: To evaluate the efficacy and safety of new anti-aging creams containing RAL at 0.1% and 0.05% used to treat photoaged skin. Patients and methods: We enrolled 40 female Korean volunteers who applied RAL 0.1% or RAL 0.05% creams twice daily for 3 months. Wrinkles on, and the textures of, both crow's feet were quantitatively assessed using the Antera 3D^® system. Transepidermal water loss (TEWL), skin hydration, the melanin index, and skin brightness were also evaluated. Overall improvement was assessed using a five-point scale by both the patients and the dermatologists. Results: The 3-month application improved overall photoaging in both RAL 0.1% (95%) and RAL 0.05% groups (95%). Both RAL 0.1% and RAL 0.05% afforded significant textural improvements (13.7% and 12.6%, respectively), reduced the TEWL (14.5%, 17.9%), and increased hydration (10.2%, 6.0%); however, no statistical differences were observed between two groups. Only RAL 0.1% significantly improved the melanin index (by 6.5%). Conclusions: Both RAL 0.1% and RAL 0.05% creams were well tolerated and improved skin hydration and texture. However, only RAL 0.1% cream improved the melanin index.