This is the question I get more than almost any other: "If it's vegan, does that mean it doesn't work as well?" I understand why people ask — for years, traditional keratin was the only option, so "keratin" and "animal-derived" became synonymous in a lot of people's minds. That's simply no longer true.
Let's separate the two things that actually matter: the protein source, and the mechanism.
Where the keratin comes from
Traditional keratin treatments source their protein from animal by-products, typically wool or hair. Vegan keratin formulas replace that with plant-derived proteins — usually from wheat, soy, or corn — engineered to mimic the same molecular structure. The hair shaft doesn't know the difference between the two at a chemical level; it responds to the protein structure being delivered, not its origin.
What actually smooths the hair
Regardless of protein source, the treatment works the same way: the formula coats and fills the cuticle, then heat from a flat iron seals it in place. That's the mechanism responsible for the smoothing, the shine, and the frizz control — and it's identical whether the base protein is animal or plant-derived.
So what's the actual trade-off?
Honestly? There isn't one that shows up in your results. Vegan keratin holds up for the same 3–5 month window, seals the cuticle just as effectively, and behaves the same way in humidity. The only difference is what's not in the bottle — no animal by-products, which matters if that's important to you, and doesn't change a thing if it isn't.
I made vegan keratin my default for exactly this reason: there was no results trade-off to justify not switching.
— Rym