At present a number of oils and shampoos are available in the market to promote hair growth. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.

Pharmacology and Therapeutics , Hyoseung Shin MD Department of Dermatology, Dongguk University Ilsan Hospital, Goyang, South Korea Search for more papers by this author Hyeong Ho Ryu MD , Hyeong Ho Ryu MD Department of Dermatology, Seoul National University College of Medicine, Seoul, South Korea Search for more papers by this author Ohsang Kwon MD, PhD , Ohsang Kwon MD, PhD Department of Dermatology, Seoul National University College of Medicine, Seoul, South Korea Search for more papers by this author Byung-Soon Park MD, PhD , Corresponding Author Byung-Soon Park MD, PhD Cellpark Clinic, Seoul, South Korea These authors contributed equally to this work. Correspondence Byung-Soon Park, md Cellpark Clinic, 60-6 Nonhyeon-Dong Gangnam-Gu Seoul 135-816 South Korea E-mail: skinmd@naver.com Seong Jin Jo, md Department of Dermatology Seoul National University College of Medicine 28 Yongon-Dong Chongno-Gu Seoul 110-744l Korea E-mail: sj.jo@snu.ac.kr Search for more papers by this author Seong Jin Jo MD, PhD , Corresponding Author Seong Jin Jo MD, PhD Department of Dermatology, Dongguk University Ilsan Hospital, Goyang, South Korea These authors contributed equally to this work.

Platelet Rich Plasma and Its Use in Hair Regrowth: A Review Published online: 19 September 2022 Table 1 DEPA Score is Categorized in Order from A to D Mechanism of Action Currently, many studies have demonstrated that platelets not only affect hemostatic system, but also affect inflammatory system, angiogenesis, stem cell induction, and cell proliferation through the release of many different growth factors and cytokines.15 Alves R , Grimalt R . A review of platelet-rich plasma: history, biology, mechanism of action, and classification . Skin Appendage Disord . 2018 ;4(1):18 –24 . doi:10.1159/000477353 29457008 [Crossref] , [Web of Science ®] , [Google Scholar] – 17 Sakata R , Reddi AH . Platelet-rich plasma modulates actions on articular cartilage lubrication and regeneration . Tissue Eng Part B Rev . 2016 ;22(5):408 –419 . doi:10.1089/ten.TEB.2015.0534 27109909 [Crossref] , [Web of Science ®] , [Google Scholar] Activated platelets in PRP release numerous growth factors and cytokines from their alpha granules, including platelet-derived endothelial growth factor (PDGF), transforming growth factor β (TGF-β), fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), glial cell line–derived neurotrophic factor (GDNF), which play a major role in stimulating hair growth through cell proliferation, differentiation and angiogenesis.18 Siah TW , Guo H , Chu T , et al. Expression patterns of the glial cell line-derived neurotrophic factor, neurturin, their cognate receptors GFRalpha-1, GFRalpha-2, and a common signal transduction element c-Ret in the human skin hair follicles . J Am Acad Dermatol . 2008 ;58(2):238 –250 . doi:10.1016/j.jaad.2007.10.014 18222320 [Crossref] , [Web of Science ®] , [Google Scholar] VEGF play a major role as a potent hair growth stimulator via an angiogenesis induction.25 Yano K , Brown LF , Detmar M . Control of hair growth and follicle size by VEGF-mediated angiogenesis . J Clin Invest . 2001 ;107(4):409 –417 . doi:10.1172/JCI11317 11181640 [Crossref] , [Web of Science ®] , [Google Scholar] ,26 Ozeki M , Tabata Y . Promoted growth of murine hair follicles through controlled release of vascular endothelial growth factor . Biomaterials . 2002 ;23(11):2367 –2373 . doi:10.1016/s0142-9612(01)00372-6 12013184 [Crossref] , [Web of Science ®] , [Google Scholar] While IGF-1 stimulates proliferation of cycling Ki67+ basal keratinocytes, induce and prolong the anagen phase of the hair growth cycle.27 Stevens J , Khetarpal S . Platelet-rich plasma for androgenetic alopecia: a review of the literature and proposed treatment protocol . Int J Womens Dermatol . 2018 ;5(1):46 –51 . doi:10.1016/j.ijwd.2018.08.004 30809579 [Crossref] , [Google Scholar] – 29 Ristow HJ , Messmer TO . Basic fibroblast growth-factor and insulin-like growth factor-I are strong mitogens for cultured mouse keratinocytes . J Cell Physiol . 1988 ;137:277 –284 . doi:10.1002/jcp.1041370210 2461376 [Crossref] , [Web of Science ®] , [Google Scholar] In addition, PRP can induce the proliferation of dermal papilla (DP) cells by activating extracellular signal-related kinase (ERK), fibroblast growth factor 7 (FGF-7), beta-catenin, and Akt signaling (an anti-apoptotic signaling molecule). There is also an increase in expression of Bcl-2 protein (an anti-apoptotic protein) in vitro human dermal papilla cells cultured with PRP.

Section snippets CLASSIFICATION Hair growth promotors can be classified according to their mode of action and the condition being treated (Table 1). ANDROGENETIC ALOPECIA Knowledge of the pathophysiology of androgenetic alopecia (AGA) is essential in understanding the mechanism of action of present therapeutic agents. The inheritance pattern appears to be autosomal dominant, although it has also been described as polygenic with heritability from either parent.43 The clinical pattern of hair loss is the result of a genetically determined distribution of androgen-sensitive hair follicles with their own specific ALOPECIA AREATA Alopecia areata is an autoimmune disease, and like many autoimmune conditions, the trigger factors are unknown.

Androgenetic alopecia is noticed as a slow transformation of large scalp terminal hair follicles to shorter, thinner, and less deep vellus hair with a much shorter anagen. Although minoxidil, finasteride, and dutasteride including other synthetic therapeutic agents are mostly used for alopecia treatment, their adverse effects encourage sorting of alternative efficient treatment agent with a limited side effect particularly herbs.