1. Most of the growth benefits of rosemary oil are based on anecdotal evidence. The claim is that the oil can treat hair loss.
2. Rosemary oil helps stimulate blood circulation to your scalp. This, in turn, promotes hair growth.
3. Rosemary oil has anti-inflammatory and analgesic properties. This can help soothe the scalp.
4. Rosemary oil cleans hair follicles and scalp. This reduces the risk of dandruff and hair loss.
A study has found that rosemary oil can help treat androgenic alopecia. The study compared the effects of rosemary oil with Minoxidil, a drug used for hair loss. The results showed that rosemary oil was as effective as 2% Minoxidil in controlling hair loss.

In another study, a topical application of rosemary extract stimulated hair growth in mice. In this case, the hair loss was initially caused by testosterone treatment.

Aromatherapy with rosemary oil (and other essential oils) also improved alopecia areata in patients. Patients who had a mixture of essential oils (including rosemary oil) massaged into their scalp daily had better hair growth.