Protein (keratine) is the basic building block of hair. It makes up 65% to 95% of the hair volume. Proteins are made of amino acids. The most important amino acid in keratin is cysteine. The high proportion of cysteine in their structure results in a large number of transverse disulfide bonds. They provide the hair with excellent properties, i.e., flexibility, damage resistance, and elasticity. The number and position of the disulfide bonds define the structure of the hair, forming curls or making it straight. Proteins are also one of the three pillars of hair care, which ensure the PEH balance of the hair.
What are proteins?
Proteins are the main building blocks of the hair stem responsible for its appearance and condition. During the hair care process, protein supplies serve as a “cement” that fills gaps in the hair structure and has a regenerative effect. Proteins have different forms and sizes, which determine how they act – on the surface of the hair or inside it. The proteins with larger molecules fill temporary defects in the hair cuticle and form an occlusive layer on the hair’s surface, which prevents water evaporation. Proteins with smaller molecules can penetrate the hair and bind relatively durable to keratin chains. They improve hair appearance and its properties, including strength, rigidity, ability to curl, and style. In addition, due to their highly hydrophilic nature, proteins can act as moisturizers.
Types of proteins
Large molecule proteins are those with the largest molecules (molecular weight >2000 Da). They work best on high porosity hair with firmly parted cuticles. For low porosity hair, they might be too heavy. They also tend to build upon the hair’s surface, which is not desirable for thin and fragile hair.
These types of proteins can include:
Milk Protein
Silk
Elastin
Collagen
Keratin
Hydrolyzed proteins. This type of protein has smaller molecules than the previous group (with a molecular weight of 800-2000 Da). They are formed through the process of hydrolysis of proteins. The relatively small size of molecules enables hair damage repair. Hydrolyzed proteins also repair damage to the hair cuticle, make hair stronger and improve its elasticity. Hydrolyzed protein molecules are suitable for all hair types, from low to high porosity. The following compounds belong to this group:
Hydrolyzed Keratin
Hydrolyzed Milk Protein
Hydrolyzed Silk
Hydrolyzed Wheat Protein
Amino acids are the tiniest molecules (molecular weight <800 Da) in the protein structure. Because of their construction and size, they are highly hydrophilic, i.e., intensely attract water molecules. They can also penetrate the hair more profoundly than hydrolyzed proteins and improve its condition for a more extended time. They work best on hair with low to medium porosity. They are also recommended as a conditioning treatment for high porosity hair. In this case, one must be careful not to provide an excessive amount of proteins. If you have this type of hair, be careful to keep the PEH balance, applying amino acids to well-moisturized hair. And after the protein treatment, remember to use a good dose of emollients. The most common amino acids found in cosmetics are:
Cysteine
Arginine
Methionine.
How to Use Proteins Properly?
Equally important as choosing the suitable proteins is the frequency of their application. It is both a mistake to avoid protein entirely or to use it excessively. Protein-deprived hair looks dull, limp, and lifeless. It is very often difficult to style the hair. For wavy hair, the curl is weak. On the other hand, hair provided with too much protein can become stiff, rough, dry, and prone to unwanted frizz. Thankfully, this is something we can deal with quite quickly. How? See here.
So how do we determine the optimal frequency of protein use for your hair type?
We can experiment and, for a while, eliminate proteins from our hair care routine. Using protein-free hair care, it is essential to carefully observe the hair and capture the moments when its condition begins to deteriorate. At this point, you should step in with high-protein products. It is still advisable to observe how they work. The frequency of using protein products is one thing. The second one is the configuration of the components for PEH balance. Small molecule proteins, designed to penetrate deeply, should be applied to well-cleansed hair. The hair treated this way has an open cuticle, and this makes the proteins penetrate easily. Proteins can act more effectively. However, the critical factor is the balance of proteins and humectants. If your hair lacks humectants, but you apply proteins to it, there is a high probability of overuse. It is also important to use emollients after proteins to provide additional protection and to smooth the hair.
The last thing is the duration of the application of the protein product. For proteins ( small molecules), we must give them time to penetrate the hair. This process lasts longer than the standard 3 minutes recommended for the majority of hair conditioners. The time frame for optimal results is around 30 minutes. You can try to speed up the process a bit (and improve the effectiveness of the proteins at the same time) by warming up the hair with a hairdryer (heat up the hair wrapped in a towel/turban). It is also effective to put a foil cap and an additional towel on the hair. In this case, you can also heat the wrapped hair with warm blow dryer air.
You can read more about proteins, humectants, emollients, and the whole PEH balance in this ebook and here.
Anwen Team
