Mechanical stimulation of the scalp in androgenetic alopecia: a narrative review of massage, tension, and mechanotransduction

Mechanical stimulation of the scalp, including manual massage and motorized devices, is a low-risk approach with a biologically credible mechanism for addressing androgenetic alopecia (AGA), but the clinical evidence supporting its efficacy is limited and immature. The review highlights that while the dermal papilla's response to mechanical forces is plausible, direct clinical evidence is sparse, with only one small uncontrolled study and a retrospective survey suggesting potential benefits. The galea-tension hypothesis and circulation arguments are interesting but not strongly supported by causal evidence. Microneedling, which operates through a different mechanism, has stronger trial support. Overall, mechanical stimulation should be considered an adjunct rather than a primary therapy, and more robust, controlled trials are necessary to substantiate its effectiveness.