If you have acne, you've probably tried many over-the-counter acne medications for it. But sometimes you need something stronger. There is a class of drugs called retinoids, which are derived from vitamin A. Tretinoin is a part of this group of medications. Tretinoin is the active ingredient in several drugs, including Retin-A. If your doctor thinks Retin-A can help your acne, you will get a prescription for it. It comes in different forms, such as gel or cream. It also comes in different strengths.

When you first start using Retin-A, your skin may get red and irritated. It may sting, or feel warm and tingly. It may burn or itch. It will feel dry and it will peel. It may also actually look as if the acne is getting worse. But over a period of time, usually a few weeks, your skin will adapt, and - hopefully - improve. Tretinoids such as Retin-A work by unplugging pores. This eliminates one of the things that can cause the pimples, zits, blemishes and blackheads we associate with acne. It can also allow other medications to work better.

Retin-A isn't the only drug with tretinoin for acne. Others are adapalene (Differin), and tazarotene (Tazorac)

You should follow your doctor's advice on how to use Retin-A. You may be told to apply it thinly once a day, for example, before you go to bed. Clean your first before applying. But, unless your doctor say otherwise, you should avoid harsh cleansers or astringents. You can apply the Retin-A with your fingertips, if you wash your hands afterwards. Or you can apply it with a gauze pad.

When using Retin-A, make sure you use sunblock or sunscreens with a high SPF. It's also important to call your doctor if you think the redness and peeling is excessive. Your doctor may advise you to use a lower strength of Retin-A. Or you may be told to use it less often. For example, instead of applying it every night, you may use it every other night.

It's also important that you don't apply anything to your face that will dry it even more. Avoid over-scrubbing your face when you wash it, as this will irritate it even more. If you are pregnant, or think you are pregnant, of if you are trying to get pregnant or are breast-feeding, tell your doctor before considering any acne medications. As with any medication, you should store Retin-A in a cabinet out of the reach of any children, where it will also be out of sunlight and heat, and kept away from excessive humidity.