A mask is not just a conditioner you leave on longer
It is a more concentrated formula designed for a longer contact time, which is a real difference rather than a marketing one. But the word "mask" covers two very different products, and the shelf does nothing to distinguish them.
A moisture mask is emollients and humectants — oils, butters, glycerin — that soften the strand and improve slip. A bond or protein treatment works on the internal structure and often leaves hair feeling rougher, not softer, immediately afterwards. Both are on this list. They are not interchangeable, and our conditioner vs mask comparison goes further into when the extra step earns its place.
Getting the balance wrong is the common failure
Too much protein and hair goes stiff, straw-like and snaps more than it did before. Too much moisture and it goes soft, limp and mushy with no bounce. People usually notice the first and misread it as "the protein is not working, I need more."
A practical rule: if your hair has been bleached in the last year, it can take protein weekly. If it has not, use a moisture mask weekly and a protein treatment once a month at most. And if hair feels stiff after a treatment, that is the signal to stop, not to repeat.
If your hair is fine
Most masks in this category are formulated for coarse hair and will flatten fine hair completely. Two strategies work. Use a leave-in format rather than a rinse-out one, so you control the dose precisely. Or apply a rinse-out mask only from the ears down and rinse thoroughly, rather than root to tip.
If you are not sure whether your hair is fine or simply low-porosity — they produce similar complaints and need different fixes — the porosity test is five minutes well spent.
How often, realistically
Weekly for dry or damaged hair. More often than that is rarely useful and, with a protein-leaning product, is counterproductive. The exception is high-porosity hair, which genuinely gets through more product and can take twice a week without going limp.
Contact time matters less than people think. Most of the benefit lands in the first five to ten minutes; sleeping in a mask mainly gets it on your pillow. Our guide to using a hair mask covers the application details that actually change the result, including the heat trick that helps low-porosity hair.
We have not used these products ourselves. They are chosen from what is in the formula, what those ingredients are documented to do, and whether that matches the problem this page is about — and every product below links to the manufacturer's own page so you can check the formulation claims yourself. The full method is here.
How we picked
Products we have personally tested: none
Most hair care roundups are written in a "we tested these" voice. We have not, and saying so is the point. These picks are chosen the way an informed shopper would choose them: read what is actually in the formula, check what those ingredients are documented to do, match that against the specific problem the page is about, and confirm the product is still being sold.
Each pick gets a role — the drugstore option, the one for high porosity, the gentlest of the set — rather than a score out of ten, because a score would imply a measurement nobody took. Nobody pays for inclusion or placement, and when the cheap product is the right answer we say that too. The full method is on one page.