Does Adapelene have anti-aging properties? If not, can Retin-a be taken with Adapelene .3%?

This is an excellent question.  Retinoids like tretinoin (Retin A), adapalene (Differin), and tazarotene (Tazorac) all act on the skin via retinoic acid receptiors (RAR).  There are three main types of RARs found in the skin - alpha, beta, and gamma.  Tretinoin activates all three kinds of RARs, while adapalene only activates RAR gamma - as a result, tretinoin is more active in the skin, while adapalene is specifically formulated to be less irritating and better tolerated than other retinoids.There are no dearth of studies demonstrating the collagen-stimulating and anti-aging effects of tretinoin.  There are comparatively few studies showing the benefits of adapalene.  While adapalene likely does have some anti-aging benefits, they likely are not as dramatic as those seen with tretinoin.  There is no benefit to combining adapalene and tretinoin - really, the only reason to chose adapalene over tretinoin is because it has less risk of skin irritation.  I hope this helps!