Somewhere between the ten-step skincare routine and the lymphatic drainage massage, our scalps got their own wellness era. There are scalp scrubs, scalp serums, scalp masks and, of course, the scalp detox. (If your shower shelf has quietly doubled this year, no judgment. Ours has too.)
Here's the thing, though: your scalp isn't toxic. "Detox" isn't a medical or dermatological term, and your scalp doesn't store toxins that need flushing out. What people really mean is a deeper clean that clears away excess oil, dead skin and the product buildup that settles on your scalp and around each follicle. That part is worth caring about, so let's look at what the research says, and what we actually tell clients in the chair.
Why your scalp matters more than you think
Your scalp is skin, and like the skin on your face, its condition shows up in what grows from it. A 2018 review linked flaky, irritated scalp conditions like dandruff to more shedding and to rougher, more breakable strands, largely down to oxidative stress around the follicle. In other words, good hair starts at the root. Literally.
What buildup actually is
Buildup is a mix of your scalp's own oil, dead skin cells and everything you put on top: dry shampoo layered over a few days, styling creams, oils and heavier, waxy formulas. Some scalps simply make more oil than others, and fine hair tends to show it first.
The signs are easy to spot. Your roots look greasy a day after washing, your hair feels coated or limp at the root, or your shampoo just doesn't leave you feeling clean anymore.
Most of my clients have no idea this is happening. They just notice their hair won’t hold volume anymore, or that it tangles no matter what they do, and assume it’s their hair. Often, it’s their water. The fix can be as simple as a shampoo made for your water, not just your hair type.
The fix is simpler than a "detox"
For most people, the answer is a good shampoo, used often enough. When a 2021 study compared wash routines in adults with healthy scalps, daily washing beat washing once a week on every scalp and hair measure, with no sign of the "over-cleaning" damage people worry about. (Consider this your sign to stop stretching wash day to day five.)
If buildup is the issue, add a clarifying shampoo every week or two. It lifts away oil and product residue more thoroughly than your everyday formula. We like the Olaplex No.4C Clarifying Shampoo. If you colour your hair, don't overdo it: clarifying too often can fade your shade and dry out your lengths, so focus it on the roots and always follow with conditioner.
What about flakes?
Not every flake is buildup. Dandruff is its own thing, and it calls for a shampoo with a proven active ingredient rather than a scrub. The American Academy of Dermatology points to zinc pyrithione, salicylic acid, selenium sulfide, ketoconazole, sulfur and coal tar, and suggests fine or oily hair use a dandruff shampoo about twice a week, while coarse or curly hair can stick to about once a week, on the scalp only.
Salicylic acid is the one to know if your scalp feels coated or flaky. It gently loosens dead skin so it rinses away, no scrubbing required.
Hard water: real, but not a crisis
If your hair feels dull or a little straw-like no matter what you do, your water might be part of it. A 2017 study found hair washed in hard water for three weeks picked up more magnesium deposits than hair washed in soft water, though without any significant visible damage to the hair's surface. Research on whether hard water actually weakens hair is mixed.
And if you're in Toronto, this one's for you. Our tap water averages about 119 mg/L of hardness, according to the City of Toronto's 2025 water analysis. That lands in the moderately hard range: not extreme, but enough minerals to leave a little residue behind over time, especially if you wash often.
So it's worth managing, not panicking over. A shampoo made for it, like the Iles Formula Hard Water Shampoo, helps lift mineral residue as you wash.
What to skip
- Harsh scrubs. Gritty physical scrubs can irritate a scalp that's already unhappy, especially if it's red or flaky.
- Stacking exfoliants. One exfoliating product at a time is plenty.
- DIY mixtures. Baking soda pastes and homemade acidic rinses can throw your scalp off balance and dry out your hair.
When to see a dermatologist
If itching, redness, burning or scaling keeps coming back even with a good routine, or you notice hair loss, broken hairs or scalp pain, book in with a dermatologist. Those can be signs of a skin condition that a shampoo won't fix, and the sooner it's looked at, the better for your hair.
So skip the detox and give your scalp what it actually wants: regular washing, the occasional deep clean and a gentle hand. Your hair will show it.
Shop the scalp reset
Shop clarifying shampoo →
Want a second opinion on your scalp? Find your stylist and ask at your next visit.
Sources: Trüeb RM, Henry JP, Davis MG, Schwartz JR. "Scalp Condition Impacts Hair Growth and Retention via Oxidative Stress." International Journal of Trichology, 2018. Punyani S, Tosti A, Hordinsky M, Yeomans D, Schwartz J. "The Impact of Shampoo Wash Frequency on Scalp and Hair Conditions." Skin Appendage Disorders, 2021. Alahmmed LM et al. "Hard water and hair: a scanning electron microscopy study." Indian Journal of Dermatology, Venereology and Leprology, 2017. American Academy of Dermatology, "How to treat dandruff." City of Toronto, "Drinking Water Analysis Summary," 2025.
