Oily Roots & Scalp

Why your roots are greasy by day two

Your scalp produces sebum continuously. That is its job, and it does not stop. So the useful question is never how to make less of it — it is what is happening to the sebum that is already there, and whether what you are putting on your roots is absorbing it or trapping it.

Three things make greasy roots worse than they need to be:

• Buildup. Conditioner, dry shampoo, styling product and hard-water minerals accumulate at the root over weeks. That layer holds oil against the scalp and makes hair look greasy sooner. This is the single most common cause, and one clarifying wash usually reveals it.
• Conditioner in the wrong place. The AAD's guidance is specific: apply conditioner to the ends if your hair is fine or straight, and along the length only if your hair is dry or curly (AAD, everyday hair care). Conditioner at the roots is grease you applied yourself.
• Touching it. Every time you push your hair back you move sebum along the strand and add some from your fingers.

Notice what is not on that list: washing too often. The idea that frequent washing makes your scalp produce more oil in retaliation is widely repeated and not supported by the AAD's own guidance, which says that if you have straight hair and an oily scalp you may want to shampoo every day (AAD, tips for healthy hair). How often should you wash your hair goes through this properly.

What each category does

Dry shampoo absorbs. Starch powder soaks up sebum so the root looks clean and has grip. It does not clean anything — it is a cosmetic delay, and used back to back for days it becomes part of the buildup problem. The AAD's own dry shampoo guidance is worth reading before you build a routine around it (AAD, dry shampoo tips).

Clarifying shampoo strips. A stronger surfactant system that removes the accumulated layer a normal shampoo washes around. Once a week at most, and never the week you had color done. See the clarifying shortlist, and scalp scrub vs clarifying shampoo if you are deciding between the two — one treats skin, the other treats hair.

Scalp scrubs exfoliate. Physical granules or a chemical acid remove dead skin and residue from the scalp surface itself, which liquid cleansers largely wash over. This is the category for a scalp that feels coated or itchy rather than hair that looks greasy. See the best scalp scrubs.

Everyday shampoo for oily hair is a lighter, lower-conditioning formula, so it does not add to the problem with every wash. That is most of the difference between it and a standard shampoo.

The reset most people need

If your hair has been greasy and flat for months and no product seems to help, do this before buying anything else. One clarifying wash. Then conditioner on the mid-lengths and ends only, never the roots. Then stop using dry shampoo for a week. A large proportion of "my hair got oilier" is buildup that has been accumulating quietly, and this reset costs almost nothing to try.

If there are flakes as well

Oily flaking and dry flaking are different conditions with different treatments, and buying the wrong one is why people conclude dandruff shampoo does not work on them. The AAD's dandruff page is the right starting point (AAD, how to treat dandruff). If the flakes are large, greasy and yellowish, that is the oily kind and an anti-dandruff active is appropriate. If your scalp is tight, itchy and shedding fine white dust, it may simply be dry — see shampoos for a dry scalp instead.

Greasy roots and dry ends

The most common combination in this whole section, and the one the product-type-organized sites handle worst, because it needs two different products in two different places on the same head. Oily scalp, dry ends explains why it happens, and the shampoo picks for oily roots and dry ends are what to buy, including the two products that handle the lengths. If your hair is also fine and flat, thickening shampoos for fine hair overlaps usefully.