Rehab fried strands with a deep conditioning, protein repair mask. Heat damaged strands have cracks, tiny holes and blisters on their outer cuticles. Protein can help smooth out the hair shaft by filling in the gaps and holes, like Spackle on a cracked wall. Let the mask soak into just-shampooed hair at least once a week.
Stick with shampoos, conditioners and leave-in smoothing balms that contain hydrating ingredients like glycerin, oils and butters. They'll add some much-needed moisture back into heat-ravaged hair.
Check the labels on styling products and opt for formulas that list "stearyl alcohol" in the ingredients. This fatty alcohol helps strengthen and soften strands made brittle by chemical straightening treatments.
Give your poor hair a vacation from blow drying or straightening until it heals. If you feel like you absolutely can't survive without your hot tools, limit styling sessions to once per week.
Hit up the salon and have your stylist lop off split ends. Unfortunately there's no way to save destroyed ends. You can mask their frizzy look with pomade, serum or hair oil, but the only way to permanently fix things is to cut damaged ends off. If the splits extend pretty high up but you're not willing to chop that much off, schedule a second trim for six weeks later, giving your hair some time to grow a little longer from the roots.
Fight off future damage with ceramic hot tools: They're undeniably a splurge, but they distribute heat more evenly for less tress stress. Set your blow dryer and iron to the lowest possible settings that will work for your hair (never exceed 400 degrees Fahrenheit) and stay under five seconds per section of hair when ironing.
Reconsider chemical straightening procedures if your hair seems especially prone to damage from these treatments.