A protein leave-in: how to tell whether your hair wants protein or moisture, and what this one adds

This page contains affiliate links. MoreThanMy earns a commission on qualifying purchases, at no extra cost to you.

Researched. We have not used this one long enough to give you a verdict, and we would rather say so than invent one. What follows is how it works, who it suits, and what it will not do. When we have used it properly, this page carries the verdict and the date.

L'Oreal Elvive Total Repair 5 Leave-In

"Damaged hair" covers two quite different problems, and they need opposite things. Some damaged hair has lost structure and needs protein. Some has lost water and needs moisture. A product built around protein — like this one — is exactly right for the first and can make the second worse.

The stretch test

Take a single strand of wet hair and gently stretch it.

It stretches a long way and does not spring back, or feels gummy and limp: the hair has lost structure, often from bleaching, colouring or years of heat. Protein helps here, by temporarily filling in the gaps along the strand.

It barely stretches before snapping, and the hair feels stiff, rough or straw-like: the hair is short of moisture. More protein can make it stiffer and more brittle. Reach for a moisturizing conditioner or an oil instead.

Many people have some of both. The test tells you which is in charge.

What this one contains

According to the listing, it is formulated with protein and almond oil, and it is aimed at hair that is weak, brittle, dull and prone to split ends. The protein is for structure and the oil is for softness and shine. It is described as light enough not to weigh hair down, with a floral, creamy scent.

The heat protection

The listing says it protects against heat up to 450 degrees. Combining a leave-in and a heat protectant in one step is practical, since both go on damp hair before styling. What a heat rating does and does not promise is explained in what the temperature on a heat protectant actually means.

How to use it

On towel-dried hair, from the mid-lengths to the ends, then comb through and style. Use it on the lengths that are damaged rather than the roots, which are the newest, healthiest hair you have.

If your hair starts to feel stiff or crunchy after a few weeks of use, that is a sign of too much protein. Alternate with a plain moisturizing leave-in, like a detangling leave-in spray, until it softens again.

How it differs from a bond builder

Protein treatments coat and temporarily fill the strand, and the effect washes out over a few shampoos. Bond-building treatments work on a different part of the hair's structure. We explain the difference in what a bond builder does, and what it cannot undo.

What it will not do

It will not permanently repair damaged hair — protein fills gaps temporarily and needs reapplying. It will not suit hair that is already stiff and brittle from too little moisture. And it will not mend split ends, which only a trim removes.

The product

A protein leave-in with almond oil and heat protection, for hair that has lost structure from colour, bleach or heat. It is the right one if your hair stretches too much when wet.

The one people are searching for is the L'Oreal Paris Elvive Total Repair 5 Protein Recharge Leave-In, 5.1 oz.

L'Oreal Elvive Total Repair 5 Leave-In

We do not print prices here, because a price we typed last month is a price that is wrong today.

Written by CatieH, who covers nails and hair here.