Protein treatments are a tad more intensive than deep conditioners. As you can probably already guess, these are made up of proteins which help to strengthen the hair against potential breakage and damage. These are ideal products to keep in your regimen if you have high-porosity hair, or hair that is damaged, colour treated, frequently heat styled, or all of the above. Having high-porosity hair just means that your hair's cuticles are raised, so doing a protein treatment every once in a while will help fill in the gaps and make your hair hold moisture in longer.
All that said, protein treatments should only be applied every four to six weeks — if used too frequently, your hair can become more susceptible to breakage. They should also be followed by some kind of moisturiser or deep conditioner.
Not all protein treatments are explicitly labelled as protein treatments (though if a product contains protein, it'll likely say so), which sometimes makes them a little difficult to spot. Read ahead for a few of our recommendations.