What is the difference between Retin-A and Retinol? And which is stronger: Retin-A .05 or Retinol .1%?

Retin-A and Retinol are both Vitamin A derivatives and they differ by how purified they are towards the end product of Retinoic Acid. Retinol is non-perscriptive and does work, though it is not as purified as Retin-A. Retinol may be gentler, but does work. Retin-A is the end product of Vitamin A and is purified retinoic acid which does penetrate the skin and is proven to genetically alter the skin through thickening the dermis or undersurface of the skin. Either product should be incorporated into a daily skin regimen and this may be altered depending on pre-existing damage and season. Retin-A may have more side-effects like peeling and redness, but it is more effective.

Any strength of Retin-A is stronger than Retinol.  Retinol is vitamin A derivative that is great for younger patients or patients intolerant of Retin-A treatment.  It is non-prescription strength.  Retin-A is the stronger workhorse of skin rejuvenation creams and penetrates deeper, which provides more of an anti-aging effect.  It's best to ease into Retin-A treatment by using it every few days at first and gradually going into a daily use regimen. 

All forms of Retin A are much more effective than even the highest Retinol. Retinol requires two metabolic steps to be converted into Retinoic acid. It is estimated that Retin A is 40 times more effective in reducing the visible signs of photoaging of the skin. I recommend retinol for those too sensitive to start Retin A. It is a good first step.

Retin-A or tretinoin is the most active retinol and, as such, is many times more powerful in correcting cellular damage, preventing sticking of the keratin layer, increasing skin vascularization and increasing collagen production in the dermis, the skin's support layer. It is a drug and is, thus, prescriptive. Since retinol is similar to Retin-A but not prescriptive, many cosmetic and cosmaceutical companies put retinol in their products to fool the public into thinking they will get the benefit of Retin-A when, in fact, they will not.