Management of hair loss
The management of hair loss, also known as alopecia or baldness, may include medications and surgery.
- 1 Medication
- 2 Surgical treatments
- 3 Radiation induced hair loss
- 4 Cosmeses
- 5 Alternative medicine
- 6 Mechanism
- 7 Research
- 8 References
- 9 External links
Treatments for the various forms of hair loss have only moderate success. Three medications have evidence to support their use in male pattern hair loss: finasteride, dutasteride and minoxidil. They typically work better to prevent further hair loss than to regrow lost hair.
They may be used together when hair loss is progressive or further regrowth is desired after 12 months. Other medications include ketoconazole, and in female androgenic alopecia spironolactone and flutamide. Combinations of finasteride, minoxidil and ketoconazole are more effective than individual use.
Minoxidil, applied topically, is widely used for the treatment of hair loss. It may be effective in helping promote hair growth in both males and females with androgenic alopecia. About 40% of men experience hair regrowth after 3–6 months. It is the only topical product that is FDA approved for androgenic hair loss. However, increased hair loss has been reported.
Finasteride is used to treat male pattern hair loss. Treatment provides about 30% improvement in hair loss after six months of treatment, and effectiveness only persists as long as the drug is taken. There is no good evidence for its use in women. It may cause gynecomastia, erectile dysfunction and depression.
There is tentative support for spironolactone in women. Due to its feminizing side effects and risk of infertility in men it is not often used in males. It can also cause low blood pressure, high blood potassium, and abnormal heart rhythms. Also, women who are pregnant or trying to become pregnant generally cannot use the medication as it is a teratogen, and can cause ambiguous genitalia in newborns.
Hair transplantation is a surgical technique that moves individual hair follicles from a part of the body called the donor site to bald or balding part of the body known as the recipient site. It is primarily used to treat male pattern baldness. In this condition, grafts containing hair follicles that are genetically resistant to balding are transplanted to bald scalp. It is also used to restore eyelashes, eyebrows, beard hair, chest hair, and pubic hair and to fill in scars caused by accidents or surgery such as face-lifts and previous hair transplants. Hair transplantation differs from skin grafting in that grafts contain almost all of the epidermis and dermis surrounding the hair follicle, and many tiny grafts are transplanted rather than a single strip of skin.
Since hair naturally grows in follicles in groups of 1 to 4 hairs, transplantation takes advantage of these naturally occurring follicular units. This achieves a more natural appearance by matching hair for hair through Follicular unit transplantation (FUT).
Donor hair can be harvested in two different ways. Small grafts of naturally-occurring units of one to four hairs, called follicular units, can be moved to balding areas of the hair restoration. These follicular units are surgically implanted in the scalp in very close proximity to one another and in large numbers. The grafts are obtained in one or both of the two primary methods of surgical extraction, follicular unit transplantation, colloquially referred to as "strip harvesting", or Follicular Unit Extraction (FUE), in which follicles are transplanted individually.
In FUT, a strip of skin containing many follicular units is extracted from the patient and dissected under a stereoscopic microscope. The site of the strip removal is stitched closed. Once divided into follicular unit grafts, the surgeon implants each unit is individually inserted into small recipient sites made by an incision in the bald scalp. In the newer technique, roots are extracted from the donor area and divided into strips for transplantation. The strip, two to three millimeters thick, is isolated and transplanted to the bald scalp. After surgery, a bandage is worn for two days to protect the stitched strip during healing. A small strip scar remains after healing, which can be covered by scalp hair growing over the scar.
Radiation induced hair loss
Radiation induces hair loss through damage to hair follicle stem cell progenitors and alteration of keratin expression. Radiation therapy has been associated with increased mucin production in hair follicles.
Studies have suggested electromagnetic radiation as a therapeutic growth stimulant in alopecia.
Certain hair shampoos and ointments visually thicken existing hair, without affecting the growth cycle. There have also been developments in the fashion industry with wig design. The fashion accessory has also been shown to be a source of psychological support for women undergoing chemotherapy, with cancer survivors in one study describing their wig as a "constant companion". Other studies in women have demonstrated a more mixed psychosocial impact of hairpiece use.
2008 and 2012 reviews found little evidence to support the use of special lights or lasers to treat hair loss. Additionally none are FDA approved for this use. Both laser and lights appear to be safe.
A 2014 and 2016 review found tentative evidence of benefit for lasers. While another 2014 review concluded that the results are mixed, have a high risk of bias, and that its effectiveness is unclear.
Dietary supplements are not typically recommended. There is only one small trial of saw palmetto which shows tentative benefit in those with mild to moderate androgenetic alopecia. There is no evidence for biotin. Evidence for most other produces is also insufficient. There was no good evidence for gingko, aloe vera, ginseng, bergamot, or hibiscus as of 2011. While lacking both evidence and expert recommendation, there is a large market for hair growth supplements, especially for products that contain biotin.
Several lines of evidence support the dermal papilla of the hair follicle as the androgenic target for hair loss prevention and reversal. Type 1 and 2 5α reductase enzymes are present at pilosebaceous units in papillae of individual hair follicles. They catalyze formation of the androgens testosterone and DHT, which in turn regulate hair growth. Androgens have different effects at different follicles: they stimulate IGF-1 at facial hair, causing hair regrowth, but stimulate TGF β1, TGF β2, dickkopf1 and IL-6 at the scalp, causing hair follicle miniaturization.
Female androgenic alopecia is characterized by diffuse crown thinning without hairline recession, and like its male counterpart rarely leads to total hair loss. Finasteride and minoxidil are usually first line therapy for its treatment. Other options include topical or systemic spironolactone or flutamide, although they have a high incidence of feminizing side effects and are better tolerated in female androgenic hair loss.
More advanced cases may be resistant or unresponsive to medical therapy, however, and require hair transplantation. Naturally-occurring units of one to four hairs, called follicular units, are excised and moved to areas of hair restoration. These follicular units are surgically implanted in the scalp in close proximity and in large numbers. The grafts are obtained from either Follicular Unit Transplantation (FUT) – colloquially referred to as "strip harvesting" – or Follicular Unit Extraction (FUE). In the former, a strip of skin with follicular units is extracted and dissected into individual follicular unit grafts. The surgeon then implants the grafts into small incisions, called recipient sites. Specialized scalp tattoos can also mimic the appearance of a short buzzed haircut. Androgenic alopecia also occurs in females, and more often presents as diffuse thinning without hairline recession. Like its male counterpart, the condition rarely leads to total hair loss. Treatment options are similar to those for men, although topical or systemic estrogen is used more often.
Bimatoprost and latanoprost
Latanoprost and bimatoprost are specific PGF2a analogues applied topically, and have been found to lengthen eyelashes, darken hair pigmentation and elongate hair. Bimatoprost is available as treatment for eyelash growth. Latanoprost has shown ability to promote scalp hair density and pigmentation, and is theorized to function at the dermal papilla. A study found latanoprost ineffective on eyelashes in a patient with alopecia areata. It has also been found ineffective in treatment of eyebrow hair loss.
Estrogens are indirect anti-androgens and can be used to treat androgenetic hair loss in females with oral contraceptives. Systemic estrogen increases SHBG, which binds androgens, including testosterone and DHT, in turn reducing their bioavailability. Topical formulations are available in Europe. Hair follicles have estrogen receptors and it is theorized topical compounds act on them directly to promote hair growth and antagonize androgen action. Large clinical studies showing effectiveness are absent. Topical treatment is also usually unavailable in North America.
In December 2012, topical application of IGF-1 in a liposomal vehicle led to thicker and more rapid hair growth in transgenic mice with androgenic alopecia. The study did not show measurable systemic levels or hematopoietic side effects, suggesting potential for use in humans. Low energy radiofrequency irradiation induces IGF-1 in cultured human dermal papilla cells. Adenosine stimulates dermal papillae in vitro to induce IGF-1, along with fibroblast growth factors FGF7, FGF-2 and VEGF. β-catenin transcription increased, which promotes dermal papillae as well. Dietary isoflavones increase IGF production in scalp dermal papillae in transgenic mice. Topical capsaicin also stimulates IGF at hair follicles via release of vanilloid receptor-1, which in turn leads to more CGRP. Ascorbic acid has led to increased IGF expression in vitro.
Stem cell therapy
Although follicles were previously thought gone in areas of complete baldness, they are more likely dormant, as recent studies have shown the scalp contains the stem cells from which the follicles arose. Research on these follicular stem cells may lead to successes in treating baldness through hair multiplication (HM), also known as hair cloning.
Per a May 2015 review, no successful strategy to generate human hair follicles, for hair regrowth, from adult stem cells has yet been reported. However, in April 2016, scientists from Japan published results of work in which they created human skin from induced pluripotent stem cells; implanted into laboratory mice, the cells generated skin with hair and glands.
From 2005 to 2007 Curis and Procter & Gamble collaborated on developing a topical hedgehog agonist for hair loss; the agent did not meet safety standards, and the program was terminated. In 2008 researchers at the University of Bonn announced they have found the genetic basis of two distinct forms of inherited hair loss. They found the gene P2RY5 causes a rare, inherited form of hair loss called hypotrichosis simplex. It is the first receptor in humans known to play a role in hair growth. Researchers found that disruption of the gene SOX21 in mice caused cyclical hair loss. Research has suggested SOX21 as a master regulator of hair shaft cuticle differentiation, with its disruption causing cyclical alopecia in mice models. Deletion of SOX21 dramatically affects hair lipids.
- Levy, Lauren L.; Emer, Jason J. (29 August 2013). "Female pattern alopecia: current perspectives". International Journal of Women's Health. 5: 541–56. doi:10.2147/IJWH.S49337. PMC . PMID 24039457.
- Banka, N; Bunagan, MJ; Shapiro, J (January 2013). "Pattern hair loss in men: diagnosis and medical treatment". Dermatologic clinics. 31 (1): 129–40. doi:10.1016/j.det.2012.08.003. PMID 23159182.
- "Propecia & Rogaine for Treating Male Pattern Baldness". Webmd.com. Retrieved May 19, 2010.
- McElwee, K. J.; Shapiro, J. S. (2012). "Promising therapies for treating and/or preventing androgenic alopecia". Skin therapy letter. 17 (6): 1–4. PMID 22735503.
- Khandpur, S.; Suman, M.; Reddy, B. S. (2002). "Comparative efficacy of various treatment regimens for androgenetic alopecia in men". The Journal of dermatology. 29 (8): 489–498. doi:10.1111/j.1346-8138.2002.tb00314.x. PMID 12227482.
- Varothai, S; Bergfeld, WF (July 2014). "Androgenetic alopecia: an evidence-based treatment update.". American journal of clinical dermatology. 15 (3): 217–30. doi:10.1007/s40257-014-0077-5. PMID 24848508.
- van Zuuren, Esther J.; Fedorowicz, Zbys; Schoones, Jan (2016-05-26). "Interventions for female pattern hair loss". The Cochrane Database of Systematic Reviews (5): CD007628. doi:10.1002/14651858.CD007628.pub4. ISSN 1469-493X. PMID 27225981.
- "Clinical utility and validity of minoxidil response testing in androgenetic alopecia.". Dermatol Ther. 28 (1): 13–6. doi:10.1111/dth.12164. PMID 25112173.
- "Minoxidil Official FDA information, side effects and uses". Drugs.com.
- "Propecia label" (PDF).
- Varothai, S; Bergfeld, WF (Jul 2014). "Androgenetic alopecia: an evidence-based treatment update.". American journal of clinical dermatology. 15 (3): 217–30. doi:10.1007/s40257-014-0077-5. PMID 24848508.
- Andersson, S. (2001). "Steroidogenic enzymes in skin". European journal of dermatology : EJD. 11 (4): 293–295. PMID 11399532.
- Avodart 0.5 mg soft capsules | SPC from the eMC
- Buchanan, J. F.; Davis, L. J. (1984). "Drug-induced infertility". Drug intelligence & clinical pharmacy. 18 (2): 122–132. PMID 6141923.
- Sinclair, R.; Patel, M.; Dawson, T. L.; Yazdabadi, A.; Yip, L.; Perez, A.; Rufaut, N. W. (2011). "Hair loss in women: Medical and cosmetic approaches to increase scalp hair fullness". British Journal of Dermatology. 165: 12–18. doi:10.1111/j.1365-2133.2011.10630.x. PMID 22171680.
- Rathnayake, D.; Sinclair, R. (2010). "Use of spironolactone in dermatology". Skinmed. 8 (6): 328–332; quiz 332. PMID 21413648.
- Yazdabadi, A.; Sinclair, R. (2011). "Treatment of female pattern hair loss with the androgen receptor antagonist flutamide". Australasian Journal of Dermatology. 52 (2): 132–134. doi:10.1111/j.1440-0960.2010.00735.x. PMID 21605098.
- Rashid, R. M.; Morgan Bicknell, L. T. (2012). "Follicular unit extraction hair transplant automation: Options in overcoming challenges of the latest technology in hair restoration with the goal of avoiding the line scar". Dermatology online journal. 18 (9): 12. PMID 23031379.
- Caroli, S.; Pathomvanich, D.; Amonpattana, K.; Kumar, A. (2011). "Current status of hair restoration surgery". International surgery. 96 (4): 345–351. doi:10.9738/cc31.1. PMID 22808618.
- Bell, M. L. (February 1982). "Role of scalp reduction in the treatment of male pattern baldness". Plastic and Reconstructive Surgery. 69 (2): 272–7. doi:10.1097/00006534-198202000-00016. PMID 7054796. Retrieved 7 December 2016.
- Unger, Martin G.; Toscani, Marco (2016). "Scalp reduction". In Scuderi, Nicolò; Toth, Bryant A. International Textbook of Aesthetic Surgery. Springer. pp. 555–556. doi:10.1007/978-3-662-46599-8. ISBN 978-3-662-46598-1. Retrieved 7 December 2016.
- Nanashima, N.; Ito, K.; Ishikawa, T.; Nakano, M.; Nakamura, T. (2012). "Damage of hair follicle stem cells and alteration of keratin expression in external radiation-induced acute alopecia". International Journal of Molecular Medicine. 30 (3): 579–584. doi:10.3892/ijmm.2012.1018. PMID 22692500.
- Kamiya, K.; Sasatani, M. (2012). "Effects of radiation exposure on human body". Nihon rinsho. Japanese journal of clinical medicine. 70 (3): 367–374. PMID 22514910.
- Takeda, H.; Nakajima, K.; Kaneko, T.; Harada, K.; Matsuzaki, Y.; Sawamura, D. (2011). "Follicular mucinosis associated with radiation therapy". The Journal of Dermatology. 38 (11): 1116–1118. doi:10.1111/j.1346-8138.2010.01187.x. PMID 22034994.
- Kalia, S.; Lui, H. (2012). "Utilizing Electromagnetic Radiation for Hair Growth". Dermatologic Clinics. 31 (1): 193–200. doi:10.1016/j.det.2012.08.018. PMID 23159188.
- Davis, M. G.; Thomas, J. H.; Van De Velde, S.; Boissy, Y.; Dawson Jr, T. L.; Iveson, R.; Sutton, K. (2011). "A novel cosmetic approach to treat thinning hair". British Journal of Dermatology. 165: 24–30. doi:10.1111/j.1365-2133.2011.10633.x. PMID 22171682.
- Zannini, L.; Verderame, F.; Cucchiara, G.; Zinna, B.; Alba, A.; Ferrara, M. (2012). "'My wig has been my journey's companion': Perceived effects of an aesthetic care programme for Italian women suffering from chemotherapy-induced alopecia". European Journal of Cancer Care. 21 (5): 650–660. doi:10.1111/j.1365-2354.2012.01337.x. PMID 22339814.
- Inui, S.; Inoue, T.; Itami, S. (2012). "Psychosocial impact of wigs or hairpieces on perceived quality of life level in female patients with alopecia areata". The Journal of Dermatology. 40 (3): 225–6. doi:10.1111/1346-8138.12040. PMID 23252418.
- Elisabeth Leamy (May 31, 2012). "Considering a hair tattoo? Pros and cons to consider before you commit". ABC News. Retrieved December 16, 2012.
- Bella Battle (February 11, 2012). "Wish you were hair". The Sun. London. Retrieved December 16, 2012.
- Rogers, NE; Avram, MR (October 2008). "Medical treatments for male and female pattern hair loss.". Journal of the American Academy of Dermatology. 59 (4): 547–66; quiz 567–8. doi:10.1016/j.jaad.2008.07.001. PMID 18793935.
- Rangwala, Sophia; Rashid, Rashid M. (Feb 2012). "Alopecia: a review of laser and light therapies". Dermatology Online Journal. 18 (2): 3. ISSN 1087-2108. PMID 22398224.
Since then, a number of studies have suggested the use of lasers as an effective way to treat alopecia, particularly androgenetic alopecia and alopecia areata, but there is still a paucity of independent, peer-reviewed blinded clinical trials.
- Avci, Pinar; Gupta, Gaurav K.; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R. (2014). "Low-Level Laser (Light) Therapy (LLLT) for Treatment of Hair Loss". Lasers in surgery and medicine. 46 (2): 144–151. doi:10.1002/lsm.22170. ISSN 0196-8092. PMC . PMID 23970445.
- Zarei, M; Wikramanayake, TC; Falto-Aizpurua, L; Schachner, LA; Jimenez, JJ (February 2016). "Low level laser therapy and hair regrowth: an evidence-based review.". Lasers in medical science. 31 (2): 363–71. doi:10.1007/s10103-015-1818-2. PMID 26690359.
- Gupta, AK; Daigle, D (April 2014). "The use of low-level light therapy in the treatment of androgenetic alopecia and female pattern hair loss.". The Journal of dermatological treatment. 25 (2): 162–3. doi:10.3109/09546634.2013.832134. PMID 23924031.
- Blumeyer, A; Tosti, A; Messenger, A; Reygagne, P; Del Marmol, V; Spuls, PI; Trakatelli, M; Finner, A; Kiesewetter, F; Trüeb, R; Rzany, B; Blume-Peytavi, U; European Dermatology Forum, (EDF) (October 2011). "Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men.". Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG. 9 Suppl 6: S1–57. doi:10.1111/j.1610-0379.2011.07802.x. PMID 21980982.
- Soni, V. K. (2009). "Androgenic alopecia: A counterproductive outcome of the anabolic effect of androgens". Medical Hypotheses. 73 (3): 420–426. doi:10.1016/j.mehy.2009.03.032. PMID 19477078.
- Inui, Shigeki; Itami, Satoshi (2013). "Androgen actions on the human hair follicle: perspectives". Experimental Dermatology. 22 (3): 168–171. doi:10.1111/exd.12024. PMID 23016593.
- "Female pattern baldness". MedlinePlus. December 15, 2012. Retrieved December 15, 2012.
- Rose, P. (2011). "The Latest Innovations in Hair Transplantation". Facial Plastic Surgery. 27 (4): 366–377. doi:10.1055/s-0031-1283055. PMID 21792780.
- Elisabeth Leamy (May 31, 2012). "Considering a hair tattoo? Pros and cons to consider before you commit". ABC News. Retrieved December 16, 2012.
- Bella Battle (February 11, 2012). "Wish you were hair". The Sun. London. Retrieved December 16, 2012.
- Kovalevsky, G.; Ballagh, S. A.; Stanczyk, F. Z.; Lee, J.; Cooper, J.; Archer, D. F. (2010). "Levonorgestrel effects on serum androgens, sex hormone–binding globulin levels, hair shaft diameter, and sexual function". Fertility and Sterility. 93 (6): 1997–2003. doi:10.1016/j.fertnstert.2008.12.095. PMID 19394598.
- Law, S. K. (2010). "Bimatoprost in the treatment of eyelash hypotrichosis". Clinical ophthalmology (Auckland, N.Z.). 4: 349–358. doi:10.2147/opth.s6480. PMC . PMID 20463804.
- Tosti, A.; Pazzaglia, M.; Voudouris, S.; Tosti, G. (2004). "Hypertrichosis of the eyelashes caused by bimatoprost". Journal of the American Academy of Dermatology. 51 (5): S149–S150. doi:10.1016/j.jaad.2004.05.002. PMID 15577756.
- Wand, M. (1997). "Latanoprost and hyperpigmentation of eyelashes". Archives of ophthalmology. 115 (9): 1206–1208. doi:10.1001/archopht.1997.01100160376025. PMID 9298071.
- Banaszek, A. (2011). "Company profits from side effects of glaucoma treatment". Canadian Medical Association Journal. 183 (14): E1058–E10F1. doi:10.1503/cmaj.109-3919. PMC . PMID 21876012.
- Blume-Peytavi, U.; Lönnfors, S.; Hillmann, K.; Garcia Bartels, N. (2012). "A randomized double-blind placebo-controlled pilot study to assess the efficacy of a 24-week topical treatment by latanoprost 0.1% on hair growth and pigmentation in healthy volunteers with androgenetic alopecia". Journal of the American Academy of Dermatology. 66 (5): 794–800. doi:10.1016/j.jaad.2011.05.026. PMID 21875758.
- Johnstone, M. A.; Albert, D. M. (2002). "Prostaglandin-induced hair growth". Survey of ophthalmology. 47 Suppl 1: S185–S202. doi:10.1016/s0039-6257(02)00307-7. PMID 12204716.
- Roseborough, I.; Lee, H.; Chwalek, J.; Stamper, R. L.; Price, V. H. (2009). "Lack of efficacy of topical latanoprost and bimatoprost ophthalmic solutions in promoting eyelash growth in patients with alopecia areata". Journal of the American Academy of Dermatology. 60 (4): 705–706. doi:10.1016/j.jaad.2008.08.029. PMID 19293023.
- Ross, E. K.; Bolduc, C.; Lui, H.; Shapiro, J. (2005). "Lack of efficacy of topical latanoprost in the treatment of eyebrow alopecia areata". Journal of the American Academy of Dermatology. 53 (6): 1095–1096. doi:10.1016/j.jaad.2005.06.031. PMID 16310083.
- Castro, R. F.; Azzalis, L. A.; Feder, D.; Perazzo, F. F.; Pereira, E. C.; Junqueira, V. B. C.; Rocha, K. C.; Machado, C. D. A.; Paschoal, F. C.; Gnann, L. A.; Fonseca, F. L. A. (2012). "Safety and efficacy analysis of liposomal insulin-like growth factor-1 in a fluid gel formulation for hair-loss treatment in a hamster model". Clinical and Experimental Dermatology. 37 (8): 909–912. doi:10.1111/j.1365-2230.2012.04441.x. PMID 22924775.
- Yoon, S. Y.; Kim, K. T.; Jo, S. J.; Cho, A. R.; Jeon, S. I.; Choi, H. D.; Kim, K. H.; Park, G. S.; Pack, J. K.; Kwon, O. S.; Park, W. Y. (2011). Najbauer, Joseph, ed. "Induction of Hair Growth by Insulin-Like Growth Factor-1 in 1,763 MHz Radiofrequency-Irradiated Hair Follicle Cells". PLoS ONE. 6 (12): e28474. doi:10.1371/journal.pone.0028474. PMC . PMID 22164296.
- Zhao, J.; Harada, N.; Kurihara, H.; Nakagata, N.; Okajima, K. (2011). "Dietary isoflavone increases insulin-like growth factor-I production, thereby promoting hair growth in mice". The Journal of Nutritional Biochemistry. 22 (3): 227–233. doi:10.1016/j.jnutbio.2010.01.008. PMID 20576422.
- Okajima, K.; Harada, N. (2008). "Promotion of insulin-like growth factor-I production by sensory neuron stimulation; molecular mechanism(s) and therapeutic implications". Current medicinal chemistry. 15 (29): 3095–3112. doi:10.2174/092986708786848604. PMID 19075656.
- Kwack, M. H.; Shin, S. H.; Kim, S. R.; Im, S. U.; Han, I. S.; Kim, M. K.; Kim, J. C.; Sung, Y. K. (2009). "L-Ascorbic acid 2-phosphate promotes elongation of hair shafts via the secretion of insulin-like growth factor-1 from dermal papilla cells through phosphatidylinositol 3-kinase". British Journal of Dermatology. 160 (6): 1157–1162. doi:10.1111/j.1365-2133.2009.09108.x. PMID 19416266.
- Valente Duarte de Sousa, Isabel Cristina; Tosti, Antonella (May 2013). "New investigational drugs for androgenetic alopecia". Expert Opinion on Investigational Drugs. 22 (5): 573–589. doi:10.1517/13543784.2013.784743. ISSN 1744-7658. PMID 23550739.
- Garza, L. A.; Yang, C. C.; Zhao, T.; Blatt, H. B.; Lee, M.; He, H.; Stanton, D. C.; Carrasco, L.; Spiegel, J. H.; Tobias, J. W.; Cotsarelis, G. (2011). "Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells". Journal of Clinical Investigation. 121 (2): 613–622. doi:10.1172/JCI44478. PMC . PMID 21206086.
- Balañá, María Eugenia; Charreau, Hernán Eduardo; Leirós, Gustavo José (May 26, 2015). "Epidermal stem cells and skin tissue engineering in hair follicle regeneration". World Journal of Stem Cells. 7 (4): 711–727. doi:10.4252/wjsc.v7.i4.711. ISSN 1948-0210. PMC . PMID 26029343.
- "Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model". Science Advances. 2 (4): e1500887. 1 Apr 2016. doi:10.1126/sciadv.1500887. Retrieved 2 May 2016.
- Weintraub, Arlene (28 June 2011). "Curis and Genentech Unleash the Hedgehog to Fight a Deadly Skin Cancer". Xconomy.
- "Curis Form 8-K: Termination of a Material Definitive Agreement.". SEC EDGAR. May 10, 2007.
- Pasternack, S. M.; Von Kügelgen, I.; Al Aboud, K. A.; Lee, Y. A.; Rüschendorf, F.; Voss, K.; Hillmer, A. M.; Molderings, G. J.; Franz, T.; Ramirez, A.; Nürnberg, P.; Nöthen, M. M.; Betz, R. C. (2008). "G protein–coupled receptor P2Y5 and its ligand LPA are involved in maintenance of human hair growth". Nature Genetics. 40 (3): 329–334. doi:10.1038/ng.84. PMID 18297070.
- Shimomura, Y.; Wajid, M.; Ishii, Y.; Shapiro, L.; Petukhova, L.; Gordon, D.; Christiano, A. M. (2008). "Disruption of P2RY5, an orphan G protein–coupled receptor, underlies autosomal recessive woolly hair". Nature Genetics. 40 (3): 335–339. doi:10.1038/ng.100. PMID 18297072.
- Sprecher, E. (2008). "Disentangling the roots of inherited hair disorders". Nature Genetics. 40 (3): 265–266. doi:10.1038/ng0308-265. PMID 18305473.
- Kiso, M.; Tanaka, S.; Saba, R.; Matsuda, S.; Shimizu, A.; Ohyama, M.; Okano, H. J.; Shiroishi, T.; Okano, H.; Saga, Y. (2009). "The disruption of Sox21-mediated hair shaft cuticle differentiation causes cyclic alopecia in mice". Proceedings of the National Academy of Sciences. 106 (23): 9292–9297. doi:10.1073/pnas.0808324106. PMC . PMID 19470461.
- Kawaminami, S.; Breakspear, S.; Saga, Y.; Noecker, B.; Masukawa, Y.; Tsuchiya, M.; Oguri, M.; Inoue, Y.; Ishikawa, K.; Okamoto, M. (2012). "Deletion of theSox21gene drastically affects hair lipids". Experimental Dermatology. 21 (12): 974–976. doi:10.1111/exd.12050. PMID 23171466.
- "Medical Treatments for Balding in Men", April 1999, American Family Physician (medical journal)