Damaging the keratin layer in your hair can result in frizzy locks, but thankfully certain products and treatments can restore straightness and smoothness. Photo: Shutterstock Methods. A search was carried out in the Pubmed, Lilacs and Scielo databases using the terms hair straightening, Brazilian hair treatment, Brazilian blowout, hair relaxer, formaldehyde hair, glyoxylic acid hair, thioglycolic hair, sodium hydroxide hair, calcium hydroxide hair, guanidine hair, potassium hydroxide hair, lithium hydroxide hair, alisamento cabelo, escova progressiva, relaxamento A keratin hair treatment is a process that infuses keratin into the hair to make it look and feel healthier and smoother. The process typically takes between 1-2 hours and can last up to four months. Keratin hair treatments can help to reduce frizz and make the hair more manageable. Keratin Treatment Side Effects. Keratin treatments are designed to straighten the hair, but they can have some undesirable side effects. The chemicals in the treatment can cause the hair to become dry and brittle, and can also lead to scalp irritation. In some cases, the treatments can also cause the hair to become frizzy and difficult to manage. 4Jbf.