“When it comes to hair bonding treatments, K18 and Olaplex are the two leaders in the category,” says King. Beloved by countless hair stylists, beauty editors, and hundreds of thousands of shoppers, Olaplex’s No. 3 is the OG of salon-grade, at-home treatments. Its famed patented technology works on a molecular level to repair broken disulfide bonds for stronger, smoother tresses. Additionally, it features glycerin, panthenol, and jojoba oil to deeply nourish.

Key ingredients: Bis-Aminopropyl Diglycol Dimaleate, citric acid, panthenol, jojoba oil

Size: 3.3 fl. oz.

Hair type: All

Amazon rating: 4.6/5 stars

An Amazon reviewer says: “Olaplex No.3 is one of the few products where the hype and before/after photos are often real. Just about everyone I know who has used it is a fan. My colorist first introduced me to this. Since the pandemic, I have been coloring my own hair, and I notice that sometimes it seems over-processed and needs a boost. I use a generous amount of the No. 3, working it thoroughly into slightly damp hair, then place a thick towel on my pillow, and sleep with the product in overnight. After a morning shower and blowout, my hair feels and looks revitalized.”