The key to choosing the best cleanser for your skin is understanding what certain soap ingredients do. Most soaps contain the following ingredients: detergents, moisturizers, fragrances and preservatives [source: Draelos]. Detergents are designed to remove dirt and oil from the skin. Moisturizers lubricate the skin and help it retain moisture, and humectants, such as glycerin, attract water into the epidermis -- making skin soft and supple. Fragrances give the soap -- and your body -- a scent, and preservatives prevent bacteria growth [source: New Zealand Dermatological Society].
Soap's main purpose is to remove dirt and bacteria from your skin, which is why soaps contain cleansing agents called surface-active agents or surfactants. Nonionic surfactants -- such as polyethylene glycols and acyl-polyglycoside -- and silicone surfactants are gentle detergents that help skin retain moisture [source: New Zealand Dermatological Society]. Syndets, synthetic cleaning agents, are another beneficial soap ingredient. They contain chemicals such as sulphur trioxide, sulphuric acid and ethylene oxide, which are gentle on sensitive skin. These soaps often have added lanolin and paraffin -- moisturizers that can benefit dry skin [source: New Zealand Dermatological Society].
If you're concerned about body odor, look for deodorant soaps that contain antiseptics and disinfectants -- such as triclosan and parachlorometaxylenol -- that can help reduce bacteria [source: New Zealand Dermatological Society]. Acne-prone skin can benefit from cleansers that contain benzoyl peroxide and salicylic acid -- these ingredients gently exfoliate the skin's surface and remove oil that can clog pores and cause pimples [source: Web MD]. If you need a cleanser that can reduce fine lines and wrinkles, look for products with antioxidants, alpha-hydroxy acids, retinoids or vitamin C [source: Bruno].
Using a cleanser that contains the right ingredients can bring out the best in your skin; however, when you wash with the wrong cleanser in the wrong place, you could irritate your skin. Keep reading to find out which ingredients to avoid.