Olaplex has some interesting chemistry

The bulk of hair is keratin, which is made up of alpha helixes, or twisted ladders of protein held together by disulfide bonds. Those bonds largely determine both the hair’s strength and its curl factor (more bonds equal more curl). Those same bonds are damaged by things like color, perming and heat styling, as well as the mechanical stress of brushing and combing.

Olaplex’s claim is that it repairs the disulfide bonds, thanks to a hero molecule called bis-aminopropyl diglycol dimaleate — clearly not named by a marketing team. Technically, the repair claim may be an overstatement: Olaplex doesn’t fuse broken bonds but instead creates a different kind of bond, said Joseph A. Schwarcz, a chemist and the director of the McGill University Office for Science and Society. (Dr. Schwarcz nonetheless pronounced Olaplex “a clever concept.”)

Perry Romanowski, a cosmetic chemist and a founder of Thebeautybrains.com, a website and podcast on which scientists examine product ingredients and industry promises, was skeptical of Olaplex’s claims. The company’s top-selling product, its No. 3 Hair Perfector, says on the label that it is “NOT a conditioner” (capital letters are Olaplex’s); it’s designed to be used before shampoo and rinsed out.

I guess there's a claim of a Michael addition to a maleate, but I gotta see evidence of that before I really believe it I guess. Plenty of chemistry and chemists in this article.