Author: Dr. William Rassman

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Hair Density in Scars

How many hairs can you transplant into a square centimeter? I have a scar, and I want to fill it in. I am trying to find a doctor who can fill it in with just one surgery. Is this a reasonable question?

An excellent question! The calculation is one that is used in the industry as a benchmark measurement. The average person with 100,000 hairs on his head has 1250 hairs per square inch or 193 hairs per square centimeter.

But what is the number to use in determining the correct density for a hair transplant? Some doctors use high density numbers to define how good they are. However, there is a balancing act between maximizing density at the time of a transplant surgery and maximizing growth months later. Experienced doctors are the key.

The reasonable upper limit of density numbers from a transplant perspective is up to 120 hairs per square cm. This type of density, however, requires supple skin that still has elastic properties. Scars do not have this characteristic. Also scars have an abnormal blood supply when compared with normal skin. Much of the infrastructure and microcirculation in the vasculature is not present in scar, so transplanting very high densities may not produce good growth.

You need to be examined by a hair transplant expert, who has the experience to give you a reasonable answer to your specific need. While I understand that you would like to have this completed in one surgery, that may not be in your best interest. Only your doctor will be able to advise you.

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Hair Doctors in the UK Remind Me of Car Salesmen

Hello, I am a 29 year old male who’s suffering from hair loss. I’ve recently been to a few consultants’ regarding hair restoration surgery in UK. Unfortunately the surgeries and the surgeons seem to be inexperienced in which I didn’t feel confident enough to go through with the surgery. Also they came across as more of sales man trying to sell me a car rather than be a respectable surgeon. I would be most grateful if you could recommend me a good surgeon, I am willing to travel to the US to get the best surgeon.

Many Thanks

Be careful not to generalize. There are immoral doctors who employ aggressive sales tactics in the United States also. There are good doctors in the UK who have good reputations and are not of the ‘used car’ variety. If you are traveling from the United Kingdom and want a hair transplant surgery in the US, you can contact Dr. Robert Bernstein in New York, which is closer than my offices in California. Dr. Bernstein was my associate for many years at NHI. Or if you don’t mind the extra 5 or 6 hours of flying time, you are more than welcome to have your procedure done at my office. If you send me your picture (which will remain confidential), my office staff can set up a phone consultation.


2007-10-18 19:04:07Hair Doctors in the UK Remind Me of Car Salesmen

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When my hair dresser dyed my hair, gobs of hair fell out on the foil. Did I get a chemical burn?

I now have a few areas of white scalp which I can see coming from where the hair fell out. Will it grow back?

Dyes can be dangerous when they are improperly used and you most likely had a chemical burn from inappropriately used dyes which goes deep below the skin to kill the hair follicles in many instances. This is unfortunately common and these chemical burns most often cause permanent hair loss. Hair transplantation works if the burn is not too extensive. ?Scalp Micropigmentation also works in some situations (see here: https://scalpmicropigmentation.com/smp-for-women/


2017-02-10 10:28:00When my hair dresser dyed my hair, gobs of hair fell out on the foil. Did I get a chemical burn?

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Hair Dye

Hair dye, it’s long term use and potential adverse health affects, has received a lot of media coverage recently. Do you think that hair-dye should be avoided? Is there any such thing as a safe hair-dye?

Dyeing your hair is not as good as not-dyeing your hair. Many people point out that when they dye their hair they get more breakage. Anytime you apply chemicals to your hair you are changing what nature thinks is the best. Periodically, I hear of people who develop hair loss from dyeing their hair. I suspect that toxic chemicals or high doses of chemicals are being used that cause this hair loss. I am often surprised by the failure of such hair to return in the most extreme cases. There is no doubt in my mind that some people overdo their hair coloring, changing it frequently and in effect ‘abusing’ their hair. Anything done in excess is not good. With regard to long term use, be responsive to what you see. Take a break from the dyeing periodically, going back to your normal hair color to see if it makes your hair better. At least, this way you will know how far from normal you have migrated to.


2005-07-21 11:37:35Hair Dye

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Hair Follicle Cells Growth Stages

My son will be 12 this August, I have been noticing lately on his pillow in the morning, there is some lose hair on it, I would say about 12 strands. I have never noticed this before and I would like to know if this is normal or something I should be concerned about. I was wondering if this could be related to puberty, his voice is starting to change or if it is coincidental? Thanks for your time.

It is normal to lose 100 to even as many as 200 hairs a day. Furthermore hair grows in cycles (see below) and you may notice more hair falling out at different phases and seasons of the month. In other words, hair growth and hair loss can be a cyclical phenomenon. Other factors certainly contribute to hair loss such as hormonal changes, malnutrition, etc. While your son’s hormonal changes of puberty may be coinciding with the hair loss, it is my opinion that 12 strands a day is perfectly normal.

Hair follicle cells have three phases of growth:

  1. Growth phase (Anagen phase) which lasts anywhere from 2 to 6 years. This is the phase where your hair is actively growing at approximately 10cm per year. 85% of hair is at this phase at any given time.
  2. Transitional phase (Catagen phase) which lasts about 2 weeks. This is the phase where the hair follicle shrinks and prepares to enter the resting phase.
  3. Resting phase (Telogen phase) which lasts about 1- 6 months. This is the phase where hair does not grow but stays attached to the follicle. Some hairs are shed at this phase, but at the end the hair follicle re-enters the growth phase to start the cycle over again. 10-15% of hairs are at this phase at any given time.


2006-04-11 08:57:21Hair Follicle Cells Growth Stages

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Hair Falling Out — Lighter Color Near Bulb

I am a 21 (about to be 22) year old male and I am currently in between a NW 2 and 3 on the balding scale. I’ve been taking propecia for about 4 months with decent results.

My question is, when I examine hair that has fallen out of my head, it appears that the hair is lighter colored at the base of the hair (near the bulb) than up around the middle and tip. Is this a sign that the hair has thinned or is it normal for hair to be lighter near the base?

You did not state your hair color. In blonde, gray or white haired people, the bulb is lighter. In hair that is near the end of its life, the pigment changes may be lighter in color as is hair that is about to go into telogen. If you are worried about balding, then get your hair mapped out for miniaturization to determine what is actually going on in your hair.


2006-10-23 14:12:29Hair Falling Out — Lighter Color Near Bulb

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Hair Falling Out When Towel Drying — Am I Being Paranoid?

I was wondering. When some of my hair falls out when I’m drying it with a towel, I notice some hair strands are thicker than others. Is that a sign of miniturization? Or am I just paranoid?

Hairs normally fall out at a rate of about 100/day, more when you wash your hair. The hairs that fall out as part of the normal hair cycle are usually normal thickness hairs, but if you lose a miniaturized hair, say goodbye to it, for it may not come back.


2008-09-10 16:41:39Hair Falling Out When Towel Drying — Am I Being Paranoid?

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The Hair Follicle as an Estrogen Target and Source (Article)

One never gets enough information. Estrogen protects the hair follicle from the genetic devastation in women that normally affects men with the same genetic code.

https://academic.oup.com/edrv/article/27/6/677/2355194


2019-02-14 06:36:48The Hair Follicle as an Estrogen Target and Source (Article)

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Hair Grew Back Wavy After I Stopped Shaving My Head

Hey Dr. Rassman..My question might be a little stupid but I’m hoping you could help me out.. I’ve been on propecia for about 2 1/2 yrs now (I’m 26 yrs old).. During most of that time I shaved my head.. I grew my hair out recently and it came back very wavy. Since then I’ve noticed a large amount of hair shedding.. However the shedding is limited to only when I shower. Between washing my hair (40-50), towel drying it (10-12), and combing it (15), I see almost 80 hairs a day.. After that I put in alot of hair spray and gel and dont see a single hair fall out. Not on my pillow, not on my desk.. nothing.. Is the large number of hairs I’m seeing in the shower ones that just couldn’t come out randomly during the day? My hair is still fairly thick so I wasnt sure if they get caught in my wavy hair..

thanks for the help..

It is normal to lose about 100 to 200 hairs a day. You may also benefit from following up with a doctor who can map your scalp hair for miniaturization to keep a quantitative record of your hair loss pattern as you continue your Propecia. With your hair short for many years, the hair loss you are now experiencing may have been happening with the short hairs such that you never noticed the fallout. The rougher you are with your longer hair, the more hair you may experience. Be gentle with the hair washing as hair that is miniaturized (impacted by genetic balding) is more far more fragile than thinning hair.

With regard to the change in hair character from straight to wavy, it is not unusual for hair character to change as we get older or as genetic balding starts to kick in. Stay on the Propecia.