• There are many acne products on the market, but only a few different active ingredients.cleaning products image by Tatiana Belova from Fotolia.com
  
  Americans spend millions, if not billions, of dollars a year on acne treatments. One trip to your local drugstore or supermarket will show you the hundreds of different products commonly available to treat acne, in addition to the prescription treatments available at your pharmacy. Yet for all of the different products out there, the number of active ingredients used to treat acne is actually quite small.
  
  

Benzoyl Peroxide

• The most commonly used over-the-counter active ingredient for acne is benzoyl peroxide. You can find it in product concentrations between 2.5 and 10 percent. It works by providing oxygen to the follicles, which kills off the p.acne bacteria inside them that causes blemishes. Benzoyl peroxide can cause some harsh side effects--including dryness, redness, irritation and peeling. Reducing the product concentration or the frequency of usage can help alleviate the side effects, along with the use of a moisturizer. Limiting the treatment to blemish spots only can also help.
  
  

Salicylic Acid

• Salicylic acid is another common ingredient in over-the-counter acne products. Products typically contain between 0.5 and 2 percent concentrations. This acid breaks down the keratin between skin cells and encourages the removal of dead skin cells that clog pores. It also slows skin cell shedding inside the follicles that clogs the pores and causes pimples. Experts consider it a gentler treatment than benzoyl peroxide, but can still result in peeling, flaking, redness and irritation.
  
  

Vitamin A Derivatives

• Tretinoin is a vitamin A derivative present in prescription products such as Renova and Retin-A. Adapalene and tazarotene are also vitamin A derivatives found in Differin, Tazorac and Avage. These products work by increasing cell turnover and prompting skin peeling, which keeps pores clear.
  
  

Antibiotics

• Topical antibiotics, such as erythromycin and clindamycin, kill the acne bacteria found on the skin and in the pores. These drugs are used in combination with vitamin A derivatives or prescription-strength benzoyl peroxide to maximize the impact of both drugs. Antibiotics kill all the bacteria on the skin, which includes the beneficial bacteria found on skin, so carefully follow your doctor's advice and do not overuse them.