So what is a keratin treatment?
A keratin treatment has become the catch-all term to refer to a hair-smoothing treatment. The exact results vary based on what type of keratin treatment you do. 
- Professional keratin treatment: breaks the bonds in hair to soften curl patterns and smooth frizz for 2–5 months (e.g.: Global Keratin Complex Hair Taming System)
 
- At-home keratin treatment: coats the hair shaft with a barrier—such as silicone—to help protect it from humidity; a flat-iron smooths everything out (e.g.: Tresemmé 7 Day Keratin Smooth Heat Activated Treatment)
 
There are also keratin hair products, such as keratin shampoos, conditioners, and masks, that add keratin to back into protein-depleted hair. This results in reduced breakage and smoother hair. 
Does my hair need a keratin treatment? 
That depends. A stylist can consult with you to determine if a professional treatment is right for you. Our comprehensive guide to keratin treatments can help too. Where it gets tricky is with at-home keratin treatments. 
If you have frizzy hair, an at-home treatment like the Tresemmé 7 Day Keratin treatment can be a good option if you don’t mind that results only last about a week. It’s significantly cheaper than a salon treatment and, apart from the flat ironing, shouldn’t damage your hair. 
If you have breakage stemming from hot tools or bleaching, a keratin shampoo or mask can be beneficial as the added protein helps rebuild the structure of your hair. However, you absolutely must add a moisturizing conditioner or mask afterward. If you don’t, your hair will feel like straw. 
Can you have too much keratin in your hair? 
You bet. When you have a protein overload, your hair feels dry and brittle—again, like straw. The solution is getting rid of products designed to add protein and focusing on moisturizing products instead. (A professional deep-conditioning treatment is a good idea, too.) 
Look at the ingredients in your hair products. If your hair feels like straw, stop using anything that contains: 
- Anything with the word protein in it (silk protein, quinoa protein, wheat protein, etc.)
 
- Keratin 
 
- Hydrolyzed collagen 
 
- Amino acids 
 
- Oat flour 
 
Another way to tell is to look at the hair product name. If the words “anti-breakage” or “strengthening” appear, it most likely contains protein.