At the hairdresser's.
Milan Markovic/iStock/Getty Images

A keratin treatment transforms curly, frizzy hair to sleek and straight with just one visit to the salon. The treatment -- which seals keratin proteins into your hair and leaves it less frizzy and more manageable -- requires careful maintenance afterward to keep your hair looking its best. This includes care while sleeping.

Sleeping

Keratin treatments last between three to five months. The length is determined, in large part, by how you care for your hair. Invest in a silk or satin pillowcase to keep your hair in its best shape. Silk and satin reduce the amount of friction between your hair and your pillow while you sleep, leading to less breakage. Other fabrics deplete hair of moisture while satin and silk won't dehydrate your hair, which means your strands stay shiny and straight for longer.

Initial Maintenance

Be very careful with your hair right after a keratin treatment. The idea is to keep your hair straight until the keratin treatment sets. For up to four days afterward, you run the risk of your strands kinking up if you manipulate them too much. Take extra care while you sleep during the first few days. Don't use elastic hair ties or pin your hair up in any way.

Fixing Kinks

If you wake up and realize your hair is a bit bent out of shape, grab your flat iron or blow dryer and restraighten your hair immediately. Take care not to get your hair wet for 72 hours after your treatment. If your hair accidentally gets wet in the shower during those first few days, immediately blow dry it.

Other Maintenance

After a keratin treatment, pick your shampoos carefully. Shampoos containing sodium-sulfate strip your hair of keratin, so use sulfate-free formulas. Chlorinated and salt water also strip keratin, so avoid swimming. If you absolutely have to take a dip, first rinse your hair with water or apply a leave-in conditioner. Both help to block chlorine and salt water from penetrating the hair shaft. Immediately rinse your hair as soon as you're done swimming.