Evaluation of Not-Activated and Activated Platelet-Rich Plasma in Hair Loss Treatment

“Evaluation of Not-Activated and Activated Platelet-Rich Plasma in Hair Loss Treatment: Role of Growth Factors and Cytokine Concentrations Obtained by Different Collection Systems”.

Gentile et al; 2017

Abs: focus on Platelet-Rich Plasma (PRP) as potential therapy for Androgenetic Areata (AGA); split study with 2 different protocols:

  • first group (18 patients) treated with Autologous not-activated PRP (A-PRP); use CPunT System or Placebo; 3 treatments per patient at 30-day intervals.
  • second group (6 patients) treated with Autologous Activated PRP (AA-PRP); use Regen or Arthrex Angel System; singular set of injections, studied at 6 months.


Intro: AGA common hair loss disorder, affecting both men and women; also known as Male Pattern Hair Loss (MPHL) and Female Pattern Hair Loss (FPHL); MPHL leads to complete baldness; FPHL characterised by gradual thinning, rarely leads to complete baldness.

Possible treatments include:

  • Finasteride: oral agent; daily treatment, 1 year before results; largely ineffective for FPHL, proven side effects that persist after treatment is stopped.
  • Minoxidil: topical agent; continuously applied to scalp to stop hair miniaturisation and prolong anagen phase; good results in patients; not approved for FPHL, causes skin irritation, dependency to treatment for long-term results.
  • Low-Level Light Therapy (LLLT): stimulates hair growth in AGA; thick hair with good tensile strength.

A-PRP: improved surgical outcome and lower recurrence rate; release of Growth Factors (GFs) and cytokines dependant on body signalling.

AA-PRP: overall better efficiency when platelets activated as GFs and cytokines released immediately.

Compared by quantifying hair count, total hair density, epidermis thickness, follicle and hair cell count.


A-PRP: criteria compared 12 weeks after treatment to baseline values; increase of hair count and hair density, increase in epidermal thickness and hair cells number.

AA-PRP: criteria compared 6 months after treatment to baseline values; half received AA-PRP from Regen, half received AA-PRP from Angel; both showed increase in hair density and follicular unit density, with Angel group exhibiting superior results; increase in hair root and epidermal thickness, higher cell count, better vascularisation; Angel system had overall better results.

GFs were quantified and compared between the different groups and systems; lower concentration and types of GFs in A-PRP than AA-PRP; Angel product had overall superior GF concentration.



Discussion: platelet activation and protein release are natural consequence in body; activated by thrombin, release of α-granules that produce GFs; activated for many functional properties (clot formation, vascularisation, cell proliferation); positive effect on hair growth.

Epidermal thickness and vascularisation contribute to healthier and more favourable environment for hair cells to develop and grow; better oxygen and nutrients supply, more room to grow in.



What to take away from paper:

  • Both A-PRP and AA-PRP seem to be a viable option to treat AGA, with more success than current technology.
  • AA-PRP has advantage over A-PRP in terms of properties and outcome for patients.
  • Angel machine appears to produce higher quality PRP, richer in GFs, both in types and concentration.