Protein treatments have long been used in the haircare world to strengthen and fortify hair that has been damaged by styling and chemical treatments. Even when not explicitly called a ‘protein treatment’ or marketed as including proteins, if you have ever gone to the salon for a reparative treatment or popped on an at-home mask for ‘weak’ or ‘damaged’ hair, it’s most likely packed with proteins.

Our hair is mainly built on protein (keratin, for you science fans out there), so if you’re trying to correct damage caused by chemical treatments such as relaxers or pre-lightening strands for colour application, protein-based treatments are a great place to start.

For damaged hair, proteins in products help to strengthen the bonds in our hair strands and in turn make our hair feel stronger and able to withstand most mechanical damage. Sounds pretty perfect, right?

The most common proteins you’ll find in hair products are “hydrolyzed wheat protein, keratin, and hydrolyzed keratin protein,” says Dr Ali Syed, founder of Avlon Hair Products. “The word hydrolyzed means that the large protein chain is cut into smaller pieces that are able to dissolve in water and are able to penetrate into hair fibre.”

As the protein is able to penetrate the hair, it can strengthen the cuticle from within rather than just coating your strands. So beyond being just cosmetic, proteins are truly transformative for damaged hair.

So, picture this: you’ve noticed that your hair is looking a little limp, breaking more than normal and feels a bit delicate. To help, you include a protein treatment in your hair washing routine, and notice that your hair feels stronger. You continue to use it every week to keep your hair feeling fortified against styling, heat, the weather and just… life, really. But then you notice your hair start to break again so you switch to another protein-rich mask, convinced the former has stopped being as effective. But it’s not. Chances are, your hair is reacting to being ladened with synthetic protein. 

This can happen to all hair types – even the most robust. In fact, if your hair is in good condition, it’ll be more susceptible to damage from overuse as the protein will begin to sit on top of your hair rather than penetrate and fill the damaged bonds. “Most proteins provide stiffness to hair, especially upon on the surface of the hair,” explains Dr Syed. “If too much protein is added, the hair becomes somewhat brittle when dry and breaks off.”

So, how do you know if you might be using too much protein?

Luckily, you can normally tell before your hair gets to the point of breakage. “It’s easy to tell if your hair is experiencing a ‘protein overload’ because it will look weighted-down and feel coated,” says Michelle Thompson, curl expert and UK DevaCurl ambassador.

If you have curly or African-Caribbean hair, it’s even more important you’re mindful with your protein use. This is because curly and textured hair tends to be more delicate than straighter hair types and can be what Michelle describes as ‘protein-sensitive’. The best way to determine whether curly hair needs protein is to pinpoint the porosity of your curls (how easily your hair absorbs moisture).

“If you have a low porosity, too much protein can cause the hair to feel brittle and dry since the protein is not getting absorbed by your curls properly,” says Michelle. “But if you have high porosity hair you will need to reach for products formulated with proteins to help your hair retain the nutrients that it can’t keep on its own.”

For hair that is fragile after chemical treatments or over-styling with hot tools, a protein treatment is great for restoring strength. However, if the breakage is caused by dryness, too much protein may exacerbate this. This calls for moisture-rich ingredients and humectants that will attract and hold moisture in the hair.

When looking for treatments and masks to aid with dryness, check the ingredients list for glycerin, honey, aloe vera and panthenol. If you’re struggling to tell the difference between fragility and dryness, the best thing you can do is reach out to your hairdresser.

“Always check with your stylist on whether a protein-rich product is the right fit for your hair,” echoes Thompson. They’ll be happy to hear from you. 

Main image: Getty