Everything you buy is doing one of two things: cleaning it, or coating it.
Once you know which, the shelf gets a lot easier to read.
That's not cynicism — it's the useful part. A product that coats the hair makes it feel smoother, look shinier, and behave better until you wash it out. That's a real benefit. It's just not repair, and anything sold as repair is selling you a temporary coating at a permanent price.
A split end is a tear in a fibre that has no blood supply and no way to knit back together. Products can glue it shut for a wash or two so it looks better. The only thing that removes a split end is scissors. If you're spending $40 on repair serum every month, you're paying for a haircut you're not getting.
Most people pick “dry” because their ends feel rough, when the actual situation is an oily scalp with dry ends — which is the most common combination there is. Buying a heavy moisturising shampoo for that makes the roots greasier and changes nothing at the ends. Look at your scalp and your ends as two separate problems, because they are.
Stripping the scalp daily tends to make it produce more oil, not less, which is how people end up convinced they have to wash daily. There's an awkward two-week adjustment when you cut back. Most people come out of it washing half as often with better hair and a product bill that dropped by half too.
Volumiser, smoother, texturiser, shine spray, anti-frizz. Most of these are the same few ingredients at different concentrations, and layering four of them mostly gets you build-up. Pick the one thing your hair actually does wrong and buy for that.
This is the single highest-value product in haircare and the one people most often skip. Straighteners and curling irons run hot enough to permanently damage the fibre, and once that's done no conditioner undoes it. A cheap heat protectant prevents more damage than an expensive repair mask fixes. If you buy one thing off this page, buy this.
Your ends are the oldest part of your hair — they've been through every wash, every brush, every hot tool since they grew. They need the coating. Your roots usually don't. Conditioner from the ears down, every time, is most of what “good hair” actually is.
So the honest shopping list is short: a shampoo that suits your scalp, a conditioner for your ends, and a heat protectant if heat ever touches your head. Everything past that is optional, and should be bought because you like it — not because you've been told your hair is broken.