Minoxidil topical treatment may be more efficient if applied on damp scalp in comparison with dry scalp

Dermatol Ther. 2016 Sep;29(5):330-333. doi: 10.1111/dth.12369. Epub 2016 Jun 30.


There is yet no consensus among prescribers whether minoxidil (MXD) formulations should be applied on wet/damp or dry scalp and no clear FDA guidelines on the matter. We hypothesized that the use of MXD on damp scalp may lead to higher drug penetration. First, because the drug diffusion and consequent deposition into the hair follicle may be favored when follicle cast is humid. Second, because humidity may also prevent drug crystallization and, therefore, maintain a higher thermodynamic activity for longer periods, which leads to increased penetration. Following in vitro experiments on rat and porcine skin we confirmed the hypothesis, which could markedly improve treatment effectiveness.

Keywords: alopecia; hair follicle; therapy-topical.

Publication types

  • Comparative Study

MeSH terms

  • Administration, Cutaneous
  • Animals
  • Crystallization
  • Diffusion
  • Hair Follicle / metabolism*
  • Minoxidil / administration & dosage*
  • Minoxidil / chemistry
  • Minoxidil / metabolism
  • Rats
  • Scalp / metabolism*
  • Skin Absorption*
  • Solubility
  • Swine
  • Time Factors
  • Water / chemistry*


  • Water
  • Minoxidil