As Seen on


Cell. 2015 Apr 9;161(2):277-90. doi: 10.1016/j.cell.2015.02.016.
Organ-level quorum sensing directs regeneration in hair stem cell populations.
Chen CC1, Wang L2, Plikus MV3, Jiang TX4, Murray PJ5, Ramos R3, Guerrero-Juarez CF3, Hughes MW6, Lee OK7, Shi S8, Widelitz RB4, Lander AD9, Chuong CM10.
Author information

Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair plucking, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Plucking hair at different densities leads to a regeneration of up to five times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-?-secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictably to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells.

I have not personally seen such responses, but I will reach out to my colleagues and ask for their opinions. I already had a response from Dr. Bernstein in New York when asked about pucking, said: “No… I’ve been plucking for years – and look where it got me.” Dr. Bernstain has a Class 6 balding pattern as you can see on his informative hair restoration site here:


I have been following your blog avidly and I see that you are very doubtful about LLLT therapy.

I have two questions. First, somewhat recently two double-blind randomized control trials for LLLT have been published (, and they provide some evidence that the treatment seems to work. These are company sponsored trials but they are published in (reputable?) journals. Have these articles in any way changed your opinion about LLLT efficacy?

Second, if someone is already on Propecia and Rogaine, do you think LLLT has sufficient evidence in favor of it that it might be worth their while as opposed to seeking no further treatment?

Block Quote

If you want to try LLLT, it is your prerogative and my opinions should not really matter. If you are trying to change my opinion on the LLLT, then I would really need to see the results first hand or read a well done study.

I have written about the studies you mention above in the past HERE, and HERE.

Propecia and Rogaine work in different ways. If someone wants to add LLLT to their treatment regimen, then it is up to them.


Dear Dr. Rassman: Yesterday, the first of 3 session for Scalp Micropigmentation at the New Hair Institute was pretty remarkable. Under the guidance of Dr. Rassman and Dr. Pak, the technicians, Christine and Leonard, delivered tens of thousands of precise ink dots that in the end look like stubble.

Along with multiple hair transplant that you, Dr. Rassman delivered 22 years ago, hopefully I’ll end up with a head of hair that has the appearance of rich, full density.

Today’s 7 hour session was like being on a mini-vacation in a comfortable lounge chair, music in the background, and light, easy chatter with the technicians. I felt embraced and well take care of.

Thanks again.


Hair transplants breed a new type of tourist in Turkey

In Turkey, revenue from popular procedures adds to country’s $7B medical tourism industry

By Nil Köksal, CBC News

“There is a new way to spot tourists in Turkey or in Iran, and it doesn’t rely on catching a glimpse of selfie sticks, maps or cameras slung around their necks.

Instead, look for the black terry cloth headbands and a telltale triangle of red spots on their scalps.” (hair transplant)

Block Quote

Doctors in Europe are feeling the pinch from competition from doctors in Istanbul Turkey and Iran who have set up hair transplant mills. This is similar to what the Russians did in the 1990s when setting up Cataract Mills for eye surgery. These are all FUE procedures and I doubt the ladies performing the FUE are all licensed doctors. It seems they are offering travel packages that cover air fare, hotel and the surgery for a 3 day stay. Of course, there is no guarantee of quality and there is no recourse if something goes wrong when these people return home after the surgery. Infections, if you get one, will have to be treated by a local doctor and if the procedure was not done right, the patient will not know for 8 months, which is the time that it takes for the hair to grow after a hair transplant. I suspect that the quality of the work ranges from good to poor, depending upon the clinic that is chosen. It is a bit of a gamble. Stay away from politics in either country or your stay may be longer than you planned.

hair transplant factory


Hi doctor, weird question. Have you ever taken a strip from the arm pit region? One would think there would be great elasticity in that area. If not, would you ever consider it?
Thanks again!

Block Quote

We have had these requests in the past. There has to be a good reason (such as depleted donor scalp hair) and a realistic understanding of its limitations (such as a difference in hair quality). It does work and we have done them.


I am 23 years old. I would like to know if the shedding phase associated with Propecia is a real thing. I was on Propecia for 2 months when a shed began. I was losing about 3 times as much hair as usual. I read on some online forums that Propecia can have a “shedding phase” where you lose a bunch of hair but it then stops and grows back. So I stayed on Propecia for an additional 2 and half months after the shed began. During this time the shed never relinquished so I stopped Propecia. My hair loss returned to its baseline rate within a few days. When I talked to my dermatologist he had never had a patient experience this “shed.” Also, on the forums it appears that for many people the shed never actually stops. For these people it just continues to fall out. This led me to believe that maybe the Propecia is causing a chronic telogen effluvium that does not cease until the drug is discontinued, as can occur with other medicine. I was considering trying Propecia again. So my question is, have you ever actually seen someone go through this shedding phase and then it stopped and they experienced no more hairloss? I would like to know if I should have stayed on the drug longer or if I just simply did not respond to it appropriately.

Block Quote

There is no shedding of hair associated with Propecia. There is however, natural genetic hair loss that still persist even while taking Propecia. In other words, Propecia does not completely stop hair loss. Propecia does not cause more hair loss. Internet forums are a collection of opinions from its members. It does not necessarily mean it is a definitive source or the correct source of information. If you are seeking a personal medical information, please see a doctor.


I recently started taking proscar in addition to the doxazosine I’ve always taken for BPH. I soon noticed that my pulse goes quite high (95-100 bpm)and stays there if I have a glass or two of wine; even hours after I stopped having wine. None of the literature mentions such a side effect, but is that the likely reason.

Block Quote

You need to speak with your doctor regarding these symptoms! You may have a heart condition unrelated to the medication you are taking. If medication is the only issue, I would suspect Doxazosine which can lower your blood pressure and cause a higher pulse rate. Your medical problem may be more than a medication issue. You really need to speak with your doctor.


Thanks for your great blog. It’s really helped me be informed about hair loss. If I am shedding many short, thin hairs that are tapered at the end, not the root, is this an early sign of male pattern balding? I assume that my hairs growth cycles are shortening and falling out before they can get long. Any advice would help. Thanks.

Block Quote

Many readers ask about the morphology of their hairs falling out and how it relates to Male Pattern Balding. We can lose about 100 hairs a day and the morphology of each hairs are variable. The miniaturized hairs are skinny and thinner as the hairs may be going into the telogen phase. Some hairs that fall may be bulky and thick and may have been just pulled out inadvertently. Some hairs may have white waxy substance known as sebum on its ends. Many readers or websites may try to correlate the hair morphology with some disease process but for the most part all of these are normal part of the hair cycle. When it comes to Male Pattern Balding, it is about the PATTERN you see in the balding pattern. If you want to take it one step further, you can put a microscope to your scalp to see if there is a variation in the diameter of hair at different locations to establish a “pattern” of miniaturiation. The very fine hairs should not constitute more than 20% of the hairs that you are looking at. This is what I often refer to as a Miniaturization Study.


Would it be reasonable to restore a hairline to look like the actor in the picture i’ve provided? would you say that the actor is balding? if so, what norwood pattern? assuming the texture is the same.

Block Quote

It would be reasonable to restore a hairline as in the photo but it would depend on what you are starting out with. If you are starting out with a Norwood 3 pattern it would be relatively easy. If you are completely bald (Norwood 6) it would be very difficult unless you have a very high donor density. You would likely need multiple surgeries as well.


This patient came in today to ask for Scalp Micropigmentation to make his hair appear thicker. It was a pleasure seeing him today. He still remembered the upbeat environment that the surgery was performed in 22 years ago! In addition, he sent a friend after he had it done.

This patient had some old plugs prior to meeting me which I camouflaged at the time of the 1993 surgery with great success. We discussed the ‘standard of care’ for hair transplants at that time and I may have been one of the few doctor who did not perform plugs then (I never performed plugs), something that he knew and appreciated. Today, we still see patients with the old plugs and I love to help them deal with it. After he has his Scalp Micropitmentation done, I will share his ‘after’ picture with you.


Page 1 of 3123

Valid CSS!

HTML 5 Validated