Both treatments live on the same salon shelf and both promise stronger, smoother hair — but they solve different problems. Using the wrong one is the most common reason a “repair” routine leaves hair feeling worse than it started.
The short answer
A keratin treatment smooths and seals the outside of the hair. A protein treatment rebuilds the inside. If your hair is frizzy and unmanageable but still stretchy and strong, you want keratin. If it snaps, feels gummy when wet, or has stopped holding a curl, you want protein.
What a keratin treatment actually does
Keratin is the structural protein hair is already made of. A keratin smoothing service coats the cuticle — the overlapping outer scales — and lays it flat, then seals it with heat. The result is less frizz, more shine, and far less blow-dry time.
What it does not do is rebuild damage. Keratin treatments are a surface fix. They are excellent for coarse, frizzy, humidity-reactive hair, and largely wasted on hair whose real problem is internal breakage.
Best for
- Frizz that returns within hours of styling
- Coarse or wavy hair that fights a blow-dry
- Humidity sensitivity
- Hair that is damaged but not yet breaking
What a protein treatment actually does
Protein treatments use hydrolysed proteins small enough to pass through the cuticle and bind to weakened areas inside the strand. Bleach, permanent colour, heat and mechanical stress all leave microscopic gaps in the cortex; protein temporarily fills them.
The effect is real but temporary — proteins wash out over several shampoos. That is a feature, not a flaw: it is what stops hair becoming brittle from over-treatment.
Best for
- Hair that snaps when you comb it
- A gummy, stretchy texture when wet
- Bleached, highlighted or repeatedly coloured hair
- Curls that have lost their pattern
How to tell which one your hair needs
Take one clean, wet strand and pull it gently.
- It stretches and springs back — your hair is balanced. Neither treatment is urgent; focus on moisture.
- It stretches and stays stretched, or snaps — you need protein.
- It snaps immediately with almost no stretch — you have too much protein already and need moisture, not more.
That last case is worth dwelling on. Protein overload looks almost identical to damage: dry, rough, brittle hair that will not hold a style. Adding more protein makes it worse. If you have been using a repair mask every wash and your hair keeps getting stiffer, stop and switch to a moisturising routine for a fortnight.
Can you use both?
Yes, and most damaged hair needs both — just not on the same day. Protein rebuilds the interior; keratin and moisture seal it. A workable rhythm for colour-treated hair is a protein treatment every three to four washes, a moisturising mask in between, and a keratin smoothing service every three to four months.
How often is too often
Protein: every two to four weeks for most people, weekly only for badly compromised hair, and always followed by a moisturising conditioner.
Keratin smoothing: every three to four months. More often than that offers no benefit, because the previous treatment has usually not fully worn off.
Where to start
If you are treating frizz, look at our Biotin & Caffeine Thickening range. If you are treating breakage, start with the Repairing Hair Care series, and pair it with something from the Moisturizing range so you are sealing the protein in rather than layering it up.
Every product we stock is 100% genuine professional stock, and if it is not right for your hair you can return it for a full refund — even opened.
If your hair is breaking rather than simply frizzing, start with how to fix over-processed hair — the repair order matters more than the product. If the damage came from colour, choosing the right shampoo for colour-treated hair is the step that stops it getting worse.
