Scalp Serum vs Hair Oil

Hair oils and scalp serums are often shelved together, but they are made for different places. One is for the hair; the other is for the skin under it. Here is how they compare, and how to use both without flat roots.

Is scalp serum the same as scalp oil?

No. A scalp oil is made of oils, usually plant oils, that sit on the skin and do not dry down. A scalp serum is usually water-based or a gel, made to spread thinly on the scalp and dry to a light finish. Some brands call an oil a serum, so check the ingredient list and the base.

What’s the difference between hair oil and hair serum?

The difference between hair oil and hair serum is mainly the base and where it goes. Hair oil is made of oils that coat the lengths and ends for shine and softness. A hair serum is lighter and smooths the surface of the hair. A scalp serum is different again: it goes on the skin at the roots.

Texture and buildup

Oils do not evaporate. On the lengths that is the point: they sit on the surface and smooth it. On the scalp, an oil mixes with the skin's own oil and stays there until you wash, and on fine hair it pulls the roots flat. A water-based scalp serum is built to dry down. Formula 01 is an alginate gel that feels thick at first, then spreads into a thin, light film.

Fine hair vs thick or curly hair

Fine or straight hair shows oil quickly, so oils are best kept to the very ends, if used at all. A light scalp product at the roots keeps the lift you style in.

Thick, coarse or curly hair often benefits from oil on the lengths, where it helps with dryness and frizz. The scalp under that hair is still skin, and it can still have its own leave-on product.

Is hair serum or hair oil better?

Neither hair serum nor hair oil is better overall; it depends on your hair and where the product goes. Oil suits dry, coarse or curly lengths that need softness. A lighter serum suits fine hair that oil weighs down. For the scalp itself, a water-based scalp serum avoids the oily roots that hair oil can leave.

Can I use scalp serum and hair oil together?

Yes, you can use scalp serum and hair oil together if each goes where it belongs. Apply the scalp serum first, to a dry scalp, and let it dry. Then warm a small amount of oil between your palms and smooth it over the mid-lengths and ends only, keeping it away from the roots.

How do you use hair oil?

Use hair oil sparingly on the mid-lengths and ends, where hair is driest. Warm a small amount between your palms, smooth it over damp or dry lengths, and add more only if you need it. Keep oil off the roots and scalp if your hair is fine, because that is where it shows first as flat, greasy-looking hair.

What to look for on a scalp serum label

Look for stated percentages of the actives, a clear base (gel, water or oil), whether it is leave-on or rinse-off, and whether it sticks to cosmetic claims. We cover each in how to choose a 2DDR serum.

Keep reading

• Side-by-side scalp care guides: side-by-side guides built on label facts
• A five-point label checklist for 2DDR serums: percentage, base, leave-on or rinse-off, preservative, claims
• A non-greasy scalp serum for fine hair: texture, finish and how much to use
• Where a serum for thicker-looking hair fits: for men and women, and where to apply it