Your straightener isn't the villain. Using it on unprotected hair is.

Each strand is wrapped in overlapping cells — the cuticle. When it lies flat, light bounces off in one direction and hair looks glossy. Heat and moisture make those cells lift, and lifted cuticles scatter light, catch on each other, and let the good stuff inside leak out.

That's the whole reason damaged hair looks dull rather than just feels rough. Dullness is a geometry problem.

Three things, in order. Proteins — hydrolyzed keratin and small peptides — slot into gaps in the damaged fiber and give it something to hold onto. Ceramide NP restores the lipid that glues cuticle cells to the strand. Film-formers then seal the surface so heat and UV hit the film, not the fiber.

Skip the third step and you protect nothing. Skip the first two and you're just laminating damage.

That's what one capsule contains, dosed and sealed so it can't oxidize on your shelf. Twist, smooth mid-lengths to ends, then style. The film goes on before the heat does — that's the entire trick.