A Randomized Control Trial Comparing the Efficacy of Platelet-Rich Plasma and 5% Topical Minoxidil for the Treatment of Androgenetic Alopecia

September 2023 | Volume 22 | Issue 9 | 905 | Copyright © September 2023


doi:10.36849/JDD.7031

Rohan Shah BAa, Mehmood Asim MDb, Samantha Ouellette BAc, Shawana Sharif MDb, Amar Shah c, Babar Rao MDa,c

aRutgers New Jersey Medical School, Department of Dermatology, Newark, NJ
bBenazir Bhutto Hospital Rawalpindi Medical University, Department of Dermatology, Rawalpindi, Pakistan
cRutgers Robert Wood Johnson Medical School, Department of Dermatology, Piscataway, NJ 

Abstract
Androgenetic alopecia (AGA) is the most common cause of hair loss in men and has limited treatment options. Minoxidil is a common therapeutic option for AGA patients because of its availability. Platelet-rich plasma (PRP) therapy is a newer option in AGA management with promising results that may be suitable for some patients. Despite a great prevalence of AGA outside the United States and Europe, there remains limited studies on the efficacy of PRP for AGA treatment. Our study's objective was to compare the efficacy of PRP and minoxidil therapy for the treatment of AGA in a Pakistani population. 72 patients were included in this randomized control trial and were either treated with PRP or topical minoxidil. After 12 weeks of treatment, the hair pull test was performed and extracted hair was counted. We report a 91.7% negative hair pull rate in the PRP treatment group which was significantly greater than the 69.4% negative hair pull rate in the minoxidil-treated group. Our study suggests that PRP therapy demonstrates a higher efficacy compared to minoxidil for treating AGA, especially in our patient demographic. These results have the opportunity to improve patient compliance and overall satisfaction while offering an improved option in patients unsatisfied with topical minoxidil.  Citation: Shah R, Asim M, Ouellette S, et al. A randomized control trial comparing the efficacy of platelet-rich plasma and 5% topical minoxidil for the treatment of androgenetic alopecia.

J Drugs Dermatol. 2023;22(9):905-909. doi:10.36849/JDD.7031

INTRODUCTION

Androgenetic alopecia (AGA) is a hereditary, androgen-dependent, dermatological disorder characterized by miniaturization of scalp hair. It is the most common type of progressive hair loss with varying severity and age of onset.1 In men, hair loss usually involves the temporal and vertex regions while sparing the occipital region resulting in a characteristic horseshoe pattern. Female hair loss is described as mid-frontal scalp hair thinning. Caucasian patients are more affected followed by Asians, African Americans, and Native Americans.2 Caucasian males are four times more likely than their black counterparts to develop AGA. In Caucasians, approximately 50% are affected by the age of 50 and 80% affected by the age of 70. In females, a notable increase in incidence is seen after menopause and approximately 57% of women over the age of 80 are affected with AGA.3
AGA is characterized by an alteration in hair cycle dynamics in which the anagen phase duration gradually decreases and the telogen phase increases.4 This is caused by overactivation of androgen receptors. AGA patients have higher production of dihydrotestosterone with higher levels of 5-alpha reductase.1 Since the anagen phase duration determines hair length, the new anagen hair becomes shorter leading to a bald appearance.4 The treatment choice for AGA focuses on halting the miniaturization process and reversing it. Medical therapy is most effective when started in the early phases of hair loss. Topical minoxidil and oral finasteride are the only two FDA-approved medical therapies for AGA.5 Topical minoxidil is available in 2% and 5% foam and liquid solutions with varying efficacy.6 It is converted to its active form minoxidil sulfate and stimulates hair proliferation at the base of the hair bulb.7 Side effects of minoxidil include irritant and allergic contact dermatitis, scalp irritation, and facial hypertrichosis. While side effects and costs are relatively limited, efficacy is often patient-dependent.8 Overall, there is a dearth of studies available evaluating the efficacy of treatments for AGA. A meta-analysis in 2017 reported a statistically significant increase in hair density compared to placebo ranging from 8.11 hairs/cm2 to 14.94 hairs/cm2 depending on factors such as strength of topical minoxidil and patient sex.5 However, a disadvantage of minoxidil is continued hair loss upon discontinuation of treatment.9 Finasteride is a 5-alpha-reductase inhibitor that has antiandrogen effects. Although generally well tolerated, there is a risk of sexual adverse effects, including gynecomastia, decreased libido, erectile dysfunction, and ejaculatory disorders.1 The meta-analysis discussed previously also evaluated studies of oral finasteride and reported a mean difference in hair density
 
of +18.37 hairs/cm2 in men compared to placebo. However, like topical minoxidil, hair loss progresses upon discontinuation of oral finasteride. Thus, while minoxidil and finasteride offer modest solutions to AGA, scientists and physicians continue to seek alternative, more robust treatment options with improved efficacy and limited side effects.10
Platelet rich plasma (PRP) has become a treatment of interest for AGA over the past two decades. PRP therapy involves intradermal injections of an autologous preparation of platelets in concentrated plasma to the scalp. PRP has been shown to improve cutaneous ischemic conditions and increase vascular structures around hair follicles.11 The high level of growth factors and cytokines in PRP facilitate tissue rejuvenation and healing. PRP has also been used in periodontal therapy, maxillofacial surgery, orthopedics, acne scar treatment, and wound healing.12 The autologous nature of PRP eliminates the risk of immune rejection or disease transmission. As a result, PRP has been a primary focus of research for AGA treatment as it is minimally invasive with limited side effects.13 In this study, we evaluated the efficacy of PRP versus 5% topical minoxidil in the treatment of AGA.

MATERIALS AND METHODS

This study was a randomized controlled trial (RCT) conducted in the dermatology department at Benazir Bhutto hospital in Rawalpindi, Pakistan. Ethical board approval was obtained prior to the start of the study, and consent was obtained from all patients. Males with AGA were selected according to the Hamilton-Norwood scale for grading male pattern hair loss, while females with AGA were selected according to the Ludwig scale for grading female pattern hair loss. Patients between the ages of 20-60 years and of both sexes were included in the study. Patients who were smokers, drug users, suffering from systemic disease, skin disease of the scalp, or other forms of alopecia, receiving AGA treatment, immunocompromised, taking non-steroidal anti-inflammatory medications, or prone to keloids were excluded from the study. Female patients who were pregnant or breastfeeding were also excluded from the study.
Patients were randomly placed into either Group A receiving PRP therapy or Group B receiving topical minoxidil therapy. Group A received PRP therapy in the form of monthly injections while Group B was provided 1 mL of topical minoxidil to be applied twice daily. Patients were followed for three months at one-month intervals. Efficacy of treatments were measured based on the hair pull test which was performed three times consecutively by the same clinician after 12 weeks of treatment. During the hair pull test, a bundle of approximately 50-60 hairs was firmly tugged away from the scalp by using the thumb and forefinger to supply steady traction and extracted hairs were counted each session. A positive hair pull test was determined by extracting four or more hairs while the extraction of less than four hairs was considered a negative pull test. At the initial visit, hair density was calculated by marking 1 cm2 patches on five different spots within the affected area of the scalp then counting hairs in each spot. An average was then calculated from these values to give a mean hair count per cm2.Data was analyzed using IBM SPSS Statistics version 23. All quantitative variables including age, hair count, and hair pull test results were presented with means and standard deviations. Qualitative variables like sex and AGA grade were presented as frequency and percentages. To compare the efficacy in terms of hair pull test between both groups, a chi-squared test was generated. AGA grade, sex, and age group were all stratified within the chi-square test and P-values less than or equal to 0.05 were considered significant.

RESULTS

A total of 72 patients with AGA were enrolled in this study, 36 in each treatment group. Both groups had 30 male patients (83.3%) and 6 female patients (16.7%) for a male to female ratio of 5:1 (Table 1). Ages ranged from 20-40 in both groups, with a mean age of 28.63 +/- 6.15 for the PRP group and 26.44 +/- 6.79 years for the 5% topical minoxidil group (Table 2). The AGA
 
grades among male and female patients in both groups were evaluated, and results are summarized in Table 3. Notably, stage II AGA was the most prevalent stage among both groups (38.9% in Group A and 41.7% in Group B).
The mean hair count before treatment was 83.50 ± 39.63 hairs/cm2 for the PRP group and 88.94 ± 36.09 hairs/cm2 for the minoxidil group. Additionally, hair pull tests were positive for all patients in both groups prior to treatment. Mean hairs per hair pull test before and after treatment are summarized in Table 5. After 12 weeks of treatment, hair pull tests were negative for 33 (91.7%) patients treated with PRP and 25 (69.4%) patients treated with 5% topical minoxidil. (Table 5) When comparing the two groups, there was a statistically significant difference between negative hair pull tests after 12 weeks (P=0.017).
When stratified by age, no significant difference was seen for negative hair pull tests between treatment groups in patients within the 20-30 age group (P=0.559) and 31-40 age group (P=0.412; Table 6). Although it did not reach statistical significance, the number of patients with negative hair pull tests of PRP treatment for male patients trended higher than their female counterparts receiving minoxidil (P=0.053). Females had no significant difference regarding number of negative hair pull tests between treatment groups (P=0.121; Table 7). Stratifying by grade of AGA did not show a statistically significant difference for negative hair pull tests between groups except for Grade II patients. 92.9% of Grade II patients in the PRP group had a negative hair pull test, compared to 46.7% in the topical minoxidil group (P=0.007).

DISCUSSION

AGA is one of the most common causes of hair loss in general practice. Limited treatment availability and efficacy have prompted the search for novel, improved therapeutics. Topical minoxidil has been a mainstay treatment of choice for AGA but with limited efficacy. Although many studies have evaluated the efficacy of minoxidil therapy and PRP therapy independently, there are very few studies comparing these two treatments. In this study, we compared PRP with topical minoxidil for treating AGA to evaluate whether PRP could be used as an alternative form of therapy. Despite PRP therapy’s use for over a decade in AGA, there is no standard treatment protocol regarding frequency and interval between two sessions. We gave PRP therapy at a monthly interval for three months, that is, three sessions one month apart which was similar to previous studies.11,14 The hair pull test was the primary method to evaluate efficacy and was conducted at 12 weeks of therapy. The same evaluation method was used by Betsi et al in which 100% of patients had a negative hair pull test after the third PRP treatment. In our study, there was a 91.7% negative hair pull rate in the PRP treatment group after 12 weeks of treatment which was significantly greater than the 69.4%
 
negative hair pull rate in the minoxidil treatment group.
 
A retrospective study compared plasma rich in growth factors (PRGF) to topical minoxidil therapy for AGA. Patients treated with PRGF demonstrated greater amounts of anagen hair compared to patients treated with minoxidil. Additionally, telogen hair decreased to a larger extent in the PRGF group.15 A separate study comparing the clinical efficacy between PRP therapy and minoxidil therapy found that patients treated with PRP had a significantly higher satisfaction score and more negative hair pull tests than patients treated with minoxidil. Furthermore, patients with a higher platelet count in their PRP injections had improved clinical outcomes compared to patients with a low platelet count in their PRP.11
 
A RCT comparing the efficacy of PRP with and without topical minoxidil, along with placebo and standard treatment, found that patients treated with a combination of PRP and minoxidil showed maximum improvement implying that these therapies may be combined as conjunctive therapy. The treatment group receiving only PRP had a greater increase in hair density compared to the recipients of minoxidil treatment alone.16 Finally, a study by Gupta et al evaluated AGA patients following 6 sessions of PRP with a gap of 15 days and found an increase in hair density and hair diameter compared to baseline.17 Contrary to the above findings, other studies have suggested that PRP is not effective in treating AGA.18,19 These contradicting studies further prompted the development of our study.
 
Evaluating PRP’s efficacy has also extended to other hair disorders including alopecia areata (AA). AA results from an autoimmune attack of the hair follicles resulting in well-circumscribed patches of sudden hair loss.20 A systematic review comparing PRP therapy to topical minoxidil suggested that there was no clear evidence that PRP or minoxidil was more effective than the other at treating AA.21 A separate review suggested that while there is initial supporting evidence to use PRP as a treatment for AA, the lack of standardized protocols prevents any adoption of PRP as a reliable treatment option.22
Another unique point of our study was the stratification of age, gender, and AGA grade. Interestingly, the 20–30 and 31–40 age groups showed no significant difference in efficacy between treatment groups. Further investigation is warranted for understanding this difference amongst age groups. Additionally, PRP treatment efficacy was significantly greater than the minoxidil-treated group in males but not females. The cause of this is unclear but may be androgen hormone mediated. Finally, in patients with AGA stage II, there was a significant difference in negative hair pull tests between treatment groups. While the cause of this is unknown, the larger n in this stage compared to other stages supports the significance of this finding and the need for further studies.

LIMITATIONS

This study was a randomized controlled trial but with two treatment groups and no placebo group. Also, our study only used the hair pull method to evaluate efficacy but studies in the past have incorporated additional metrics including patient satisfaction and global photography imaging. These values would have further substantiated the results from the hair pull test while also providing another way to evaluate AGA disease extent. Additionally, factors such as frequency of hair washing and brushing may influence results of the hair pull test.

CONCLUSION

PRP therapy can be a valuable treatment option for patients with AGA as well as an adjuvant to topical minoxidil therapy. Our study showed that PRP therapy demonstrates a higher efficacy compared to minoxidil for treating AGA. These improved results may result in better patient compliance and overall satisfaction, however further studies are needed. PRP may be a better treatment option, especially in patients who are unsatisfied or are noncompliant with regular use of topical minoxidil or oral finasteride.

DISCLOSURES

The authors have no conflicts of interest to declare.

REFERENCES

  1. Lolli F, Pallotti F, Rossi A, et al. Androgenetic alopecia: A review. Endocrine. 2017;57:9-17.
  2. He F, Shen M, Zhao Z, et al. Epidemiology and disease burden of androgenetic alopecia in college freshmen in China: A population-based study. PloS One. 2022;17(2):e0263912.
  3. Birch MP, Messenger AG. Genetic factors predispose to balding and non-balding in men. Eur J Dermatol.  2001;11:309-314.
  4. Nguyen B, Tosti A. Alopecia in patients with COVID-19: A systematic review and meta-analysis. JAAD Int. 2022;7:67-77.
  5. Adil A, Godwin M. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis. J Am Acad Dermatol. 2017;77:136-41.e5.
  6. Freire PCB, Riera R, Martimbianco ALC, et al. Minoxidil for patchy alopecia areata: systematic review and meta-analysis. J Eur Acad Dermatol Venereol. 2019;33(9):1792-1799.
  7. Abdin R, Zhang Y, Jimenez JJ. Treatment of androgenetic alopecia using prp to target dysregulated mechanisms and pathways. Front Med (Lausanne). 2022;9:843127.
  8. Nestor MS, Ablon G, Gade A, et al. Treatment options for androgenetic alopecia: Efficacy, side effects, compliance, financial considerations, and ethics. J  Cosmet Dermatol. 2021;20(12):3759-3781.
  9. Suchonwanit P, Thammarucha S, Leerunyakul K. Minoxidil and its use in hair disorders: a review.  Drug Des Devel Ther. 2019;13:2777-86.
  10. Abdallah MAE, Shareef R , Soltan MY. Efficacy of intradermal minoxidil 5%injections for treatment of patchy non-severe alopecia areata. J Dermatolog Treat. 2022;33(2):1126-1129.
  11. Verma K, Tegta GR, Verma G, et al. A study to compare the efficacy of platelet-rich plasma and minoxidil therapy for the treatment of androgenetic alopecia. Int J Trichology. 2019;11(2):68-79.
  12. Cervantes J, Perper M, Wong LL, et al. effectiveness of platelet-rich plasma for androgenetic alopecia: A review of the literature. Skin Appendage Disord. 2018;4(1):1-11.
  13. El Taieb MA, Ibrahim H, Nada EA, et al. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic evaluation. Dermatol Ther. 2017;30(1).
  14. Cervelli V, Garcovich S, Bielli A, et al. The effect of autologous activated platelet rich plasma (AA-PRP) injection on pattern hair loss: Clinical and histomorphometric evaluation. BioMed Res Int. Epub 2014 May 6:760709.
  15. Navarro MR, Asín M, Martínez MA, et al. Management of androgenetic alopecia: a comparative clinical study between plasma rich in growth factors and topical minoxidil. Eur J Plast Surg. 2016;39:173-80.
  16. Singh SK, Kumar V , Rai T. Comparison of efficacy of platelet-rich plasma therapy with or without topical 5% minoxidil in male-type baldness: A randomized, double-blind placebo control trial.  Indian J Dermatol Venereol Leprol. 2020;86(2):150-177.
  17. Gupta AK, Carviel J , Abramovits W. Treating alopecia areata: current practices versus new directions. Am J Clin Dermatol. 2017;18(1):67-75.
  18. Mapar MA, Shahriari S , Haghighizadeh MH. Efficacy of platelet-rich plasma in the treatment of androgenetic (male-patterned) alopecia: A pilot randomized controlled trial. J Cosmet Laser Ther. 2016;18(8):452-455.
  19. Puig CJ, Reese R , Peters M. Double-blind, placebo-controlled pilot study on the use of platelet-rich plasma in women with female androgenetic alopecia. Dermatol Surg. 2016;42(11):1243-1247.
  20. King BA, Senna MM, Ohyama M, et al. Defining severity in alopecia areata: current perspectives and a multidimensional framework. Dermatol Ther (Heidelb). 2022;12(4):825-834.
  21. Sproul S. Efficacy of platelet rich plasma injections vs topical minoxidil in androgenic alopecia. Physician Assistant Studies: Student Articles. 2020;15.
  22. Almohanna HM, Ahmed AA, Griggs JW, et al. Platelet-rich plasma in the treatment of alopecia areata: a review. J Investig Dermatol Symp Proc. 2020;20:S45-S49.

AUTHOR CORRESPONDENCE

Rohan Shah BA rs1520@njms.rutgers.edu
Close Menu