Peppermint Oil Promotes Hair Growth Without Toxic Signs

In a 2014 study, 3% peppermint oil (PEO) was found to significantly promote hair growth in C57BL/6 mice over a period of 4 weeks, compared to saline, jojoba oil, and 3% minoxidil. The PEO group showed increased hair follicle number, depth, and dermal thickness, along with higher levels of alkaline phosphatase activity and insulin-like growth factor-1 (IGF-1) expression, both of which are indicators of hair growth. The PEO treatment was comparable to minoxidil, a standard hair growth medication, and did not result in any toxic signs or significant changes in body weight or food efficiency. The study suggests that PEO could be an effective agent for hair growth, potentially by inducing an early anagen stage and promoting vascularization of the hair dermal papilla. The number of mice used in the study was small, with 3, 3, and 5 mice at weeks 1, 2, and 4, respectively.