Can I use Retin-A on my legs, arms, and hands?

Application in multiple areas does not increase the absorption of retinoid products being applied. The study was done in 1997 by Latriano and colleagues and published in Journal of the American Academy of Dermatology.it is also important to provide deep moisturization and hydration to the skin with an Opti-Ceramide cream and also a wide spectrum high SPF sun block. I recommend the following regimen to my patients as it was developed by a plastic surgeon and skin specialist in Santa Monica at Kare Skin. Use the Opti-Ceramide cream (Elevase) and the wide spectrum (UVA, UVB) sun block with high SPF (50+) Spectrase. 
You can also use a retinoid product and you have 3 choices. You can read about them in detail on the link below. Replenish is the "Level 1" mild strength retinoid for sensitive skin and for mild daily exfoliation, improving fine lines & wrinkles, reducing acne, and brightening your complexion. You may want to go with "Level 3"  retinoid which is RR Complex with power boost strength retinoid for deep daily exfoliation, improving fine lines & wrinkles, reducing acne, and brightening your complexion.H Karamanoukian MD FACS