After a keratin treatment is applied to black permed hair, the hair is straightened with a high-temperature flat iron. The heat infuses the keratin into the hair, seals the cuticles and repairs damaged hair. Keratin treatments work well on permed, relaxed and colored hair, leaving it straighter and less frizzy.
Keratin treatments work best on curly, coarse, frizzy and thick hair. It is a temporary straightener, wearing off each time hair is washed. Keratin normally lasts from six weeks to several months. The treatment process takes several hours to complete. For the first few days after getting a keratin treatment, hair should not be washed or allowed to get wet. Exercise or anything that causes sweating should be avoided. Pulling hair up, pinning it back or putting it into a ponytail during the first few days following treatment can cause kinks in the hair.
Keratin is a structural protein found in skin, nails and hair. Many keratin products contain formaldehyde in very small amounts, which is used to aid the straightening process. Other keratin treatments include greater amounts of formaldehyde, which could be potentially harmful. Frequent or high exposure to formaldehyde leads to watery eyes, headaches and difficulty breathing. Some keratin treatments are formaldehyde-free.