Protein sensitivity is a term that is thrown around a lot these days which got me curious. Is that even a real thing? In the scientific community it certainly is not recognized as being a technical term. So what’s really happening on the hair that led people to declare that they are protein sensitive?
Let’s talk about proteins
Proteins are made up of amino acid chains, and they are densely packed in hair as fibrous protein to form the keratin fibers. Unfortunately fragments of these proteins (from ‘wear and tear’) get lost over time during shampooing and other treatments. Hair products will often use hydrolyzed proteins which are smaller fragments of soluble protein. These have been found to be beneficial to hair for various reasons: smoothing, film forming on cuticles, softening, strengthening etc. Amino acids are often used as well for the same benefits.
Why protein sensitivity doesn’t add up entirely
Before you declare war with proteins, you need to have a controlled experiment: testing the same product with and without the protein ingredient. This is of course impossible to do unless you are the one formulating the product. My point is that comparing one product with proteins with another without proteins (from a different brand) is like comparing apples to oranges. Every single brand will formulate differently: different sources for their ingredients, different recipe, different amounts. So it doesn’t make sense to say that product X contains protein and therefore I am changing to product Y without proteins. We need to account for all the variables in place within one product.
With that being said, I do agree that protein treatments could have undesirable impacts on some. Protein treatments consist of delivering high concentrations of protein based ingredients to the hair. Not everybody is suitable for this. The treatments are beneficial mostly to those with highly porous hair. But then again virgin porous hair might react differently to chemically treated hair. An example of such treatment is the Aphogee Two-step Treatment Protein for Damaged Hair. The first ingredient is hydrolyzed collagen, and it lists many more protein based ingredients.
Why porous hair? Because porous hair allows more water/surfactants into the fiber causing fragments of protein to leave. Over time, the hair loses some of its strength and vitality from this loss. Adding proteins to this type of hair can help maintain hair health. If your hair doesn’t need the extra boost of protein, it can feel stiff, and not very pliable leading to a feeling of dryness. Too much of a good thing is not good. [Same with over-conditioning. Read here.] Luckily these proteins do not stick to hair for long and can be removed fairly easily within a few shampoos if needed.
Unless you are adding proteins intentionally as a treatment, it is almost impossible to know if you have the so called protein sensitivity. It is most likely that you are using products (not just one ingredient) that don’t match well with your hair type/needs. So I would say do not fret over the low concentrations of protein used in regular hair products. They do have a role to play in helping your hair just like the other conditioning agents. Concerns should be redirected primarily on things such as: the type of surfactants, the level of conditioning of the product vs. hair type, types of silicones if any, fragrance for those sensitive etc.