Ingredients and actives

Rosemary oil

Also written as hair growth oil, scalp serum, hair oil.

The scalp oil that carried hair care into skincare shelves. Thin, aromatic, and applied to the scalp rather than the hand.

What it needs from a bottle

Scalp application needs a nozzle that reaches through hair. A standard dropper puts oil on hair rather than skin, so a fine applicator tip or a comb applicator is what the category has settled on.

Formats that suit it

• Applicator-tip bottles
• Amber glass droppers