Keratin is the type of protein that makes up your hair, skin, and nails. Keratin can also be found in your internal organs and glands. Keratin is a protective protein, less prone to scratching or tearing than other types of cells your body produces.

Keratin can be derived from the feathers, horns, and wool of different animals and used as an ingredient in hair cosmetics. Since keratin is the structural building block of your hair, some people believe that keratin supplements, products, and treatments can help strengthen your hair and make it look healthier.

People who use keratin on their hair report that their hair is smoother and easier to manage as a result. The effects vary greatly depending on whether your hair is healthy to begin with, what the natural thickness of your hair is, and what kind of keratin treatment you use. Keratin works by smoothing down the cells that overlap to form your hair strands. The layers of cells, called the hair cuticle, theoretically absorb the keratin, resulting in hair that looks full and glossy. Keratin also claims to make curly hair less frizzy, easier to style, and straighter in appearance.

Salon keratin treatments

Sometimes called the Brazilian keratin treatment, this time-intensive method of using keratin involves several steps. First, a cream that contains formaldehyde is applied to your hair before it’s blown dry and straightened in a salon. Once the treatment is applied, you’re instructed to keep your hair dry for several days. When you visit the salon to have the chemicals washed out, another treatment is applied to “set” the straightening effect. This treatment claims to last for 12 weeks.

Keratin serums, shampoos, and conditioners

Keratin serums, shampoos, and conditioners can’t make the same claims as a keratin treatment in a salon. But they do claim to make hair more damage-resistant and repair hair that has been dried out by heat and hair dye. To identify these products, look for the words “keratin hydro lysates” in the ingredients list. Researchers concluded in 2013 that the active components of keratin were a promising ingredient for people that wanted stronger hair.

Keratin supplements

You can find keratin supplements for sale at nearly any health food store. Keratin supplements come in powder and capsule forms. Keratin supplements are not without risks. If overused, they can cause too much protein to build up in your body.

Keratin treatments done by a beauty professional range in price according to your area, the brand of product being used, and how pricey your salon is. Keratin treatments top out at $800, but can be found for as low as $300.

You can also find at-home keratin treatment kits in some pharmacies and beauty supply stores. These keratin treatments may be messy or difficult to apply correctly, especially if you’ve never seen the treatment performed by a professional. But if you’re comfortable with trying it, at-home keratin treatments are usually less than $50.

Salon keratin treatments contain large amounts of formaldehyde. Some employees at hair salons even reported nosebleeds and respiratory problems from handling the keratin treatment products and inhaling their fumes repeatedly over time. These levels of formaldehyde exceeded the national safety standard for chemical exposure by five times. For that reason, pregnant women should avoid getting this treatment. People with a sensitivity to formaldehyde or respiratory problems should also avoid keratin treatments.

Keratin treatments do have some benefits. By applying keratin to your hair cuticle and sealing it in with heat, your hair takes on a glossier appearance. But before getting a treatment like this, it’s critical to understand the chemicals involved. Some people may find that after they get a keratin treatment once, they have to keep getting the treatment so that the heat damage from processing their hair this way doesn’t show. Keratin treatments also expose hair salon employees to high levels of chemicals that are toxic over time. Before getting a keratin treatment, consider trying out a hair product that contains keratin to see if you can achieve the glossy locks you’re looking for.