Styling without shedding: Novel topical formula reduces hair shedding by contracting the arrector pili muscle

Dermatol Ther. 2018 Jan;31(1). doi: 10.1111/dth.12575. Epub 2017 Nov 28.


Approximately 40% of women experience excessive hair shedding during styling (e.g., hair brushing). Previously, we demonstrated that topically applied phenylephrine, a potent α1 adrenergic receptor agonist, can be used to contract the arrector pili muscle of the follicular unit; thus, increasing the force required to pluck hair and reducing shedding during brushing. While demonstrating efficacy, phenylephrine has several drawbacks when applied to the scalp, including the possibility cardiovascular events. We hypothesized that a high concentration of a weak α1 agonist would allow for: (a) rapid penetration through the stratum corneum eliciting a quick response; (b) a low probability of cardiac adverse events owing to the low receptor binding affinity; and (c) an efficacy of the weak α1 agonist similar to that of phenylephrine at the local site of application. Accordingly, we developed a novel topical solution, AB-102, containing a high concentration of a weak α1 agonist. Several studies were conducted to test the safety and efficacy of AB-102. In a dose escalating safety study, utilizing a wearable holter monitor, we observed no cardiac or hemodynamic adverse events. In addition, in a controlled efficacy study, AB-102 reduced the number of hairs shed during brushing by up to 77% (average of 38%).

Keywords: arrector pili; hair shedding; piloerection.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Administration, Topical
  • Adolescent
  • Adrenergic alpha-1 Receptor Agonists / administration & dosage*
  • Adrenergic alpha-1 Receptor Agonists / adverse effects
  • Adult
  • Alopecia / diagnosis
  • Alopecia / physiopathology
  • Alopecia / prevention & control*
  • Blood Pressure / drug effects
  • Electrocardiography, Ambulatory
  • Female
  • Hair Follicle / drug effects*
  • Hair Follicle / physiopathology
  • Hair Removal
  • Heart Rate / drug effects
  • Humans
  • Piloerection / drug effects*
  • Scalp
  • Synephrine / administration & dosage*
  • Synephrine / adverse effects
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Adrenergic alpha-1 Receptor Agonists
  • Synephrine