Traditionally, rosemary has been used by herbalists to relieve muscle pain and spasm, stimulate hair growth, and support the circulatory and nervous systems. It is also believed to affect the menstrual cycle, act as an abortifacient (inducing miscarriage), relieve menstrual cramps, increase urine flow, and reduce kidney pain (for example, from kidney stones).
Rosemary has been regarded by some as a memory enhancer. That belief can be traced back to ancient Greece, where students would put sprigs of rosemary in their hair while studying. It has also been used to treat alopecia, a disease (of unknown origin) causing significant hair loss, usually in patches. In one study of eighty-six people with alopecia, those who massaged their scalps with rosemary and other essential oils (including lavender, thyme, and cedarwood) every day for seven months experienced significant hair regrowth compared to those who massaged their scalps without the essential oils. It is not entirely clear from this study whether rosemary (or a combination of rosemary and the other essential oils) was responsible for the beneficial effects.
In one laboratory study, rosemary extract increased the effectiveness of doxorubicin in treating human breast cancer cells. Further studies on humans are needed, but meanwhile, those taking doxorubicin should consult their doctors if taking rosemary. Both laboratory and animal studies suggest that rosemary’s antioxidant properties may have activity against colon, breast, stomach, lung, and skin cancer cells.