Relaxed hair is weaker than natural hair due to the reconstitution of the disulfide bonds that occur during the process of loosening or relaxing one’s natural curl pattern. The high alkalinity of the relaxing chemicals themselves also raise the hair’s cuticles and there will be gaps in the cuticles even after a neutralizing shampoo has been used to lower the hair’s pH. These are the reasons why it is important to include protein conditioners and deep conditioning treatments such as protein hair masks in your hair care regimen. You will need regular protein treatments especially if:

Your hair is chemically colored or bleached

Color treatments – particularly permanent ones – lift the scales of the cuticle and interact with the cortex to alter the natural pigment of the hair. Bleaches work similarly but tend to be more traumatic on the hair.  Even for people with un-relaxed natural hair, this process of lifting the cuticle scales may leave the hair weakened and/or prone to dryness.  Using a high quality protein hair mask or treatment can temporarily fill gaps in the cuticle, allowing for strengthened hair that retains more moisture.

You use direct heat (especially regularly)

Even with appropriate use of direct heat, the hair may still suffer some damage to the scales of the cuticle.  In this case, using a protein hair treatment prior to a heat straightening session can help the hair sustain manipulation and prevent breakage.

Your hair is more than two years old 

When the ends of your hair have been with you for two years, it is not uncommon to see ends that are worn down to the last cuticle layer or cortex … or split.  (Imagine the amount of wear and tear that has accumulated over that time frame!)  In some cases, a trim is all that is needed while in others a trim followed by a regular protein conditioning thenceforth may be what is required.  The latter case is especially true for many of those who are BSL (Bra strap length) or beyond that are struggling to grow their hair even longer.  Regular use of protein conditioners or protein hair masks can help to reduce breakage of the ends – the oldest, most worn segment of your hair.

You have fine or porous hair

Now, not every person with fine hair needs to incorporate protein treatments, but for some it may be very useful towards reducing breakage during manipulation (e.g., styling, detangling).  Why?  This is because, with fine strands, both the cuticle and cortex are thinner than in thicker strands.  Consequently, fine hair has less natural strength and is more prone to damage.