Cutaneous application of α-methylspermidine activates the growth of resting hair follicles in mice

In the 2009 study, researchers found that the cutaneous application of α-methylspermidine (α-MeSpd) on mice induced the transition from the resting phase (telogen) to the growth phase (anagen) of hair follicles after 2 weeks. The study, which involved 5 mice in the control group and 6 mice in each of the two treatment groups, showed that α-MeSpd penetrated the skin and partially replaced natural polyamines, leading to an increased total pool of polyamines including the analog. This resulted in pigmentation, growing hair follicles, increased proliferation of follicular keratinocytes, and upregulation of β-catenin. These findings suggest that polyamines are significant in hair cycle regulation and that hair growth can be stimulated using stable polyamine analogs.