George Cotsarelis, MD
Dermatology
Sees patients age 18 and up
Penn Dermatology Radnor
View 1 additional location
Schedule onlineCall 610-902-2400
Penn Medicine Provider

About me

  • Chair, Department of Dermatology
  • Milton Bixler Hartzell Professor of Dermatology

Education and training

  • Medical School: University of Pennsylvania School of Medicine
  • Residency: Geisinger Hospital
  • Residency: Hospital of the University of Pennsylvania
  • Fellowship: Hospital of the University of Pennsylvania

What my patients think about me

Average Rating

139 reviews

Comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Penn Medicine.

October 2025
attention to detail
September 2025
dr. cotsarelis is a great doctor who has a great bedside manner and very knowledgeable.
September 2025
it is a 5
August 2025
i have been suffering with alopecia for years. i have been too many dermatologist. i've tried many remedies. this is the only doctor where i have seen market success. he is wonderful at knowing how to help people with alopecia.

Insurance accepted

My Locations

Penn Medicine hospital privileges

  • Hospital of the University of Pennsylvania: Has privileges to treat patients in the hospital.
  • Pennsylvania Hospital: Has privileges to treat patients in the hospital.
  • Penn Presbyterian Medical Center: Has privileges to treat patients in the hospital.
Dr. Cotsarelis is a Penn Medicine physician.

Qualifications and experience

Treatments and Conditions

My research

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. Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells. , J Clin Invest, 121(2): 2011,613-622

Ito, M., Yang, Z., Andl, T., Cui, C., Kim, N., Millar, S.E. Cotsarelis, G. Wnt-dependent de novo hair follicle regeneration in adult mouse skin after wounding. , Nature, 447: 2007,316-321

Fan, C., Luedtke, M.A., Prouty, S.M., Burrows, M., Kollias, N., Cotsarelis, G. Characterization and quantification of wound-induced hair follicle neogenesis using in vivo confocal scanning laser microscopy. , Skin Research and Technology, 17(4): 2011,387-97

*Ito, M., *Liu, Y., Yang, Z., Nguyen, J., Liang, F., Morris, R., Cotsarelis, G. *equal contributors Stem cells in the hair follicle bulge contribute to wound repair but not to homeostasis of the epidermis. , Nature Medicine, 11: 2005,1351-1354

*Morris, R., *Liu, Y., Marles, L., Yang, Z., Trempus, C., Li, S., Lin, J., Sawicki, J., Cotsarelis, G., *equal contributors Capturing and profiling hair follicle stem cells. , Nature Biotechnology , 22: 2004,411-417

Trempus, C.S., Dang, H., Humble, M.M., Wei, S.J., Gerdes, M.J., Morris, R.J., Bortner, C.D., Cotsarelis, G., Tennant, R.W. Comprehensive Microarray Transcriptome Profiling of CD34-Enriched Mouse Keratinocyte Stem Cells. , J Invest Dermatol, 127: 2007,2904-7

Trempus, C.S., Morris, R.J., Ehinger, M., Elmore, A., Bortner, C.D., Ito, M., Cotsarelis, G., Nijhof, J.G., Peckham, J., Flagler, N., Kissling, G., Humble, M.M., King, L.C., Adams, L.D., Desai, D., Amin, S., Tennant, R.W. CD34 expression by hair follicle stem cells is required for skin tumor development in mice. , Cancer Res, 67: 2007,4173-81

Endo, M., Zoltick, P.W., Peranteau, W.H., Radu, A., Muvarak, N., Ito, M., Yang, Z., Cotsarelis, G., Flake, A.W. Efficient in vivo targeting of epidermal stem cells by early gestational intraamniotic injection of lentiviral vector driven by the keratin 5 promoter. , Mol Ther, 16: 2008,131-7

Lyle, S., Christofidou-Solomidou, M., Liu, Y., Elder, D., Albelda, S., Cotsarelis, G. The C8/144B monoclonal antibody recognizes cytokeratin 15 and defines the location of human hair follicle stem cells. , J Cell Science, 111: 1998,3179-3188

Kantor, J., Jay, L., Brooks, D., Cotsarelis, G. Decreased Serum Ferritin is Associated with Alopecia in Women. , J Invest Dermatol, 121: 2003,963-968