A 2015 study compared rosemary oil to minoxidil, a popular hair regrowth treatment. People with DHT-related hair loss received either rosemary oil or minoxidil for 6 months. By the end, both groups saw significant increases in hair growth.
However, the group that was treated with rosemary oil had more hair growth compared to the other.
While the difference was not statistically significant, the results suggest that rosemary oil may promote hair growth in the long term with continued use. In the same study, scalp-itching was more common in the group that received minoxidil, so rosemary oil could be a better option for people with a history of allergies or skin irritation.
A 2013 study involving mice with testosterone-related hair loss found that rosemary oil could regrow their hair. A study published in 2017, found that rosemary oil may kill some fungi and bacteria suggesting that hair loss caused by an infection or unhealthy scalp may be treated with rosemary oil with prolonged use. Alopecia areata is an autoimmune disorder that can cause hair loss. Research published in 1998 looked at the effect of aromatherapy using rosemary oil on people with the condition. Some 44 percent of participants improved with the use of rosemary over 7 months, compared to just 15 percent who received no treatment.
According to some scientific evidence, rosemary may benefit nerve tissue. Carnosic acid, an active ingredient in the plant, was observed to heal tissue and nerve damage in one study. This ability to heal nerve endings may suggest that continued use on the scalp may rejuvenate local nerves thus possibly promoting hair growth.
More revealing recent studies show that rosemary directly helps protect against hair loss. One 2015 trial pitted the essential oil against minoxidil, commercially known as Rogaine. Both were used on human subjects with androgenetic alopecia (male or female pattern baldness).
Results showed that rosemary essential oil was just as effective a minoxidil. During the process, it helped the side effect of itchy scalp more successfully than minoxidil.
Another study of rosemary leaf extract (different from the essential oil) showed it stimulated hair growth. This occurred when hair loss was triggered by testosterone (as in pattern baldness). This study was performed on mice, however.
Two separate clinical reviews — one from 2010 and the other from 2011 — also acknowledged rosemary’s hair growth potential. The former cites a study with successful hair regrowth in people with alopecia who used essential oils.
One of these essential oils was rosemary.
In the latter review, rosemary essential oil was described as a hair loss restorative. This was due to its circulation-improving effects.
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