Update: In June 2019, Dr. George Cotsarelis made an interesting presentation titled “Two Decades of Riding the Hair Wave”:
University of Pennsylvania’s Dr. George Cotsarelis is a legend in the hair loss world. He has probably been among the three most quoted hair loss researchers in the world over the past two decades (with the other two being Dr. Angela Christiano and Dr. Ken Washenik). I have covered all three of these US-based researchers dozens of times on this blog in the past.
Dr. Cotsarelis’ first hair related study that I could find is dated all the way back from 1990. Since then, the doctor and his lab (sometimes in collaborative efforts with others) have been responsible for a number of groundbreaking discoveries in relation to androgenetic alopecia. These include crucial findings related to progenitor cells, prostaglandin D2, skin regeneration, Wnt signaling, wounding and more.
Dr. Cotsarelis is a co-founder of Follica, a company of paramount importance to us in 2018. I therefore thought it would be of interest to find some important quotes and thoughts that Dr. Cotsarelis has given in the past two decades to major newspapers and scientific publications.
George Cotsarelis Quotes
The quotes below give a good indication about the overall progression of hair loss research in the US during the past several decades. They also suggest major revisions in prognostications about when a hair loss cure will finally arrive.
1998
Science News (need subscription)
“Ideally, you would like to turn on beta-catenin just in an adult and see if you have the same effect: production of hair follicles.”
1999
“If someone thinks this is going to lead to a baldness cure in a year or two, that’s completely unrealistic. I think seven to 10 years is more realistic.” 
2000
BioScience (need subscription)
“The discovery of the human homologue of the mouse hairless gene defect beautifully shows that the hair follicle in the mouse is very similar to the human, and that’s heartening because a lot of people are working on mouse and assuming that it’s going to be relevant to humans.”
“It’s not crazy by any means. At some point in the future, I wouldn’t be surprised if there were some type of gene therapy for hair loss.”
2004
“I think this or something like it will be available in the next five to 10 years” said George Cotsarelis, a dermatologist at the University of Pennsylvania school of medicine who led the research.”
2007
“Dr. George Cotsarelis, a dermatology professor at the University of Pennsylvania School of Medicine in Philadelphia who led the study, said the findings dispel the dogma that hair loss is permanent in people and other mammals, and that once they are lost new hair follicles cannot grow. Cotsarelis said the findings could pave the way for remedies for male-pattern baldness and other types of hair-loss. He said the idea would be to apply compounds to get epidermal cells to turn into hair follicles. Cotsarelis is involved with Follica Inc., a privately held start-up company that has licensed the patent on the process from the University of Pennsylvania. He said it probably would be more than five years before a treatment was possible.”
2007
“For this to become therapeutic, you’d probably have to find ways to activate the Wnt pathways with a topical agent,” Cotsarelis says. He notes that he and his colleagues have founded a small start-up company called Follica to create a product that could be applied to injured skin as it heals to “activate the right pathways … [that trigger] follicle formation.” Cotsarelis says the for-profit venture is now only doing preclinical experiments, but if all goes perfectly, there could be a product on the market in two to three years.”
2008
A great overview of Dr. Cotsarelis’ work through 2008 can be found in the above publication and is worth a complete read. Key quote:
“When cells move in to close a wound, they are trying to make a decision: Should I make epidermis or should I make a hair? If there is a lot of Wnt around, they choose to become hair follicles.”
My Note: Besides an instructive summary of how the lab’s hair research has developed and progressed every few years, I was very surprised to read about how important Dr. Mayumi Ito’s work has been in some of the key findings, especially wounding. Dr. Ito now works at her own lab in New York and has been covered on this blog a number of times in the past.
2011
“This implies that there is a problem in the activation of stem cells converting progenitor cells in bald scalp. The fact that there are normal numbers of stem cells in bald scalp gives us hope for reactivating those stem cells.”
2011
“Dr Cotsarelis, a dermatologist, whose work was part-funded by the US government and by L’Oreal, believes a treatment could be on the market within a decade.”
2012
“Dr. Cotsarelis, who describes himself as enamored with the hair follicle, has been hard at work on balding scalps since he identified hair follicle stem cells in mice in 1990, when he was a postdoctoral fellow. We were able to show that when we isolated the cells and injected them into another mouse, he said, the mouse made new hair follicles.”
2013
“George Cotsarelis, professor and chair of dermatology at the Perelman School of Medicine at the University of Pennsylvania, in Philadelphia, is skeptical of product claims. Topical products can change the hair’s appearance but not the follicle itself, he cautions. It’s like throwing gasoline on your car and expecting it to go.”
My Note: Maybe he forgot about topical Minoxidil and topical Finasteride?
2014
“Cotsarelis was adamant about it because male pattern baldness isn’t related to the immune system.”
My Note: It is therefore a bit strange that Follica (Puretech) classifies androgenetic alopecia to be an immune system related problem per recent presentations.
2016
“In the end, I think there are going to be multiple ways to treat male pattern baldness, and some will work fabulously well in some people and not so well in others.”
2017
“Essentially, we can manipulate wound healing so that it leads to skin regeneration rather than scarring.”