What to Know About Cocamidopropyl Betaine

Medically Reviewed by Debra Jaliman, MD on July 23, 2023
4 min read

If you’re concerned about what you put on your skin, you may find yourself trying to decipher personal care product labels. The ingredients lists on hair care and skin care products can be confusing. The names of ingredients often sound like topics from a chemistry class. As a result, you may find yourself wondering what sort of things you're being exposed to when you use your favorite facial cleanser or shampoo.

One ingredient you may see listed is cocamidopropyl betaine. It's a cleansing ingredient found in dozens of products. It's been used in personal care products for decades, especially in items meant to clean skin or hair. If you tried to use it alone, it wouldn't give you a deep cleaning effect on your hair or skin, but it makes cleansers work better when it's combined with other ingredients.

Cocamidopropyl betaine has been in commercial use since the 1950s. It was initially used during World War II as a cleanser that could lather up in cold water. Later, the first cocamidopropyl betaine shampoo was developed using coconut oil as a base. The mild formula lathered well but wasn't as astringent as typical detergents. It became the famous "no more tears" baby shampoo.

Cocamidopropyl betaine works as a cleanser and conditioner, though it’s primarily a surfactant. Surfactants are ingredients that attract dirt and oil so that you can rinse them off of your skin or hair. Soaps and shampoos are all surfactants.

Cocamidopropyl betaine is made of fatty acids derived from coconut oil and blended with other elements during manufacturing. On its own, it's a viscous fluid. Product makers use it as an additive to increase the effectiveness of other ingredients. It serves several functions, including:

Lather. Cocamidopropyl betaine produces a thick lather when combined with water. The lathering action helps loosen the dirt and impurities that you are washing away, so they are easier to rinse off after cleaning.

Hydration. Many detergents are drying to hair or skin. Cocamidopropyl betaine contains coconut oil, which is hydrating. It's less drying than other surfactants. Cocamidopropyl betaine reduces the drying effects of harsher detergents in skin and hair care products.

Thickening. Cocamidopropyl betaine makes products feel creamier. It's a thickening agent that adds viscosity to products. This makes them feel richer and makes them less likely to drip while you use them.

Sometimes you may see an ingredient list that says coco betaine instead of cocamidopropyl betaine. This isn't a typo or abbreviation. Coco betaine is a different ingredient, though it has a similar function.

Where cocamidopropyl betaine contains both natural and synthetic elements, coco betaine is natural. The coco in the name refers to coconut oil. All-natural betaine is an amino acid that comes from beets. Those two natural substances do the same thing as cocamidopropyl betaine.

Like its synthetic counterpart, coco betaine is also a surfactant. It works to boost cleansing effects. It has the same lathering and hydrating effects as cocamidopropyl betaine, too.

The ingredients in coco betaine are entirely plant-based and don't contain any synthetic ingredients. It's not nearly as common as the synthetic version, but you might see it in organic or all-natural brands.

Cocamidopropyl betaine has a wide range of uses. It’s most frequently used as a cleanser, but you might also see it in other personal care products, including:

  • Contact lens solutions
  • Gynecological or anal wipes
  • Hair conditioners
  • Makeup remover
  • Liquid body wash
  • Liquid soap
  • Shampoos
  • Shaving cream
  • Toothpaste

Cocamidopropyl betaine received notoriety in 2004 after it was named the Allergen of the Year by the American Contact Dermatitis Society. Doctors had discovered that some people develop a rash after coming in contact with cocamidopropyl betaine. The itchy or painful skin reaction is called allergic contact dermatitis.

There had been reports of allergic contact dermatitis related to cocamidopropyl betaine dating back to 1983. By the 1990s, experts believed that manufacturing problems leading to impurities in the formula were the real issue. As the use of products with cocamidopropyl betaine increased worldwide, so did reports of allergic reactions to them. By 2004, the American Contact Dermatitis Society considered cocamidopropyl betaine to be a noteworthy allergen and spotlighted it.

The all-natural alternative coco betaine has not been as widely studied for its allergenic potential. But it’s not more gentle than the synthetic version. It's considered to be more irritating, especially to sensitive skin.

If you have an allergy to either coco betaine or cocamidopropyl betaine, the best treatment is to stop using them. Most personal care products list ingredients on the packaging or on their website. You can use that information to choose products that won't irritate your skin.