Rice protein is particularly effective at increasing hair volume by up to 32% with ongoing use. Clinical trials have shown 13.1 % increase in hair volume after only 5 washes. The rice protein we use and that is used in studies is hydrolyzed. Hydrolyzed protein is broken down into very small proteins. This allows the protein to enter your hair shaft, filling in voids, making hair smoother and shinier. The proteins also bond to the hair to create more volume. Rice protein accomplishes this by binding to the negatively charged hair structure, which creates space in between your hairs, giving it more volume. Rice proteins are lightweight and are good for thinner hair, such as grey hair that is naturally thinner than the hair it replaced, heavier proteins can weigh down thinner hair, causing it to be flat. Larger proteins also don't penetrate the hair, they can cake it and can have a crunch, hair spray like effect. If you are interested in this bar or are interested in purchasing wholesale shampoo bars in general, please reach out to us to open an account for your store.