Protein sensitivity. . .
Protein sensitive, one of the many neologisms coined on the hair forums, describes hair that reacts badly to protein-based products. Typically, the hair will show some stiffening and, in the worst cases, even take on strawlike, brittle state. Why exactly it occurs is not 100% clear. Sometimes, the problem can be traced to overuse: typically protein products work by depositing small particles into holes in the hair shaft left by damage. Using too much at once, not cleansing it effectively or using the product too frequently, runs the risk of creating buildup, as layer after jagged layer of the protein residue accumulate on the hair shaft.
If this happens often enough and with different products containing protein, it's likely a case of incompatibility between the hair and the ingredient type.
Some hair does not take kindly to products being left on its surface, particularly protein-based ingredients which tend to have a natural stiffness to them.
While they work similarly, many people who do not do well with proteins find their hair flourishes with polysaccharides. Popular haircare ingredients containing natural polysaccharides include kelp, marshmallow root extract, aloe vera and flax seed gel.
One of the few oils that can actually penetrate the hair, coconut oil has been clinically proven to protect against protein loss from the inside out. It takes several hours to actually get deep into the hair shaft, but once it does, coconut oil crosslinks to the hair's natural keratins holding them in place. Try a pretreatment with this oil to get maximum benefits, since it takes so long to penetrate.
Because of coconut oil's dramatic strengthening powers, some protein-sensitive folk presume that it contains protein and avoid it for that reason. This is a mistake: as an oil, coconut oil is 100% lipid: it contains no protein whatsoever. When it comes to boosting your hair's strength, oils have several advantages over protein.
Many women who have little luck with proteins are able to cut them out of their haircare regimen completely, by making sure they keep their hair well-moisturised.
Please remember, though, that the strength derives from the moisture levels within your hair when it is “dry”. Keeping the hair wet all the time means keeping it in a weak state and is thus counterproductive.
If you plan on going the moisture-only route and not replacing the protein with another strengthener, it is vital that you keep up your routine for optimal hydration. Layer your products to make sure your hair is kept insulated and stick to the conditioners that make your hair the smoothest and most flexible.
By keeping tabs on your elasticity, and maintaining hydration at healthy levels, you can ensure that your hair is as resilient as can be, without having to rely on proteins.
The Argonne National Laboratory