As Seen on


All Density related posts


Hi Dr. Rassman et al.!

I am a 22-year-old Caucasian male with blond hair, a NW2 hairline and somewhat low hair density. I’m not worried about my hairline, but my low density bothers me.

Here’s the thing: I have hydrocephalus, and with it an abnormally large head circumference. I’ve always had thin hair, but I shaved my head for the first time the other day and the density really scared me. Given my history of thin hair, is it possible that my low density is due to my scalp being “stretched” and causing the follicles to spread apart? The hair at the back of my head is slightly denser than at the top, but it’s very fine and light-colored. I know this is an unusual question and I understand if you can’t offer any answers.

Thanks for your time and all the advice you give!

Block Quote

I suppose if you start with a normal scalp hair number (100,000 hairs), but with a large head circumference (large area), you would have a lower hair density (hair numbers per unit area). But for those with normal head circumference, you can still have low hair density because some of us can be born with low hair numbers. It’s just the way we are different.

Hair color and skin color can also contribute to the perception of hair density or fullness. High contrast (dark hair / light skin) can be perceived as a lower density than low contrast (light hair / light skin). Hair length can also change the perception, as longer hair looks more full than shorter hair.

Finally, hair style can be a factor, as well. Curly hair looks more full than straight hair. These factors may be common sense, but it all plays a factor in how one perceives density and fullness of hair.

If you were to visit us, we could measure your hair density in different parts of your head, compare one part with another and give you an assessment of your total hair count and any differences that are area dependent.

Tags: density, hairloss, hair loss


Hi guys,

I started thinning when I was 19 and this continued slowly up until I turned 25 when it became far more aggressive and has continued in that vein for 18 months now. I had tried Minoxidil over a year to seemingly no effect and I had significant side effects from using finasteride. Overall in the past 18 months I’ve gone from a Norwood II to a Norwood IV and adjusting has been extremely difficult.

The back and sides appear to be decreasing in density at a similar rate (although they have more hair than across the top, as you would expect) and for that reason I’m very concerned I would not be a good candidate for hair transplant surgery.

I guess my question is whether this is attributable to only androgenetic alopecia, or could there be an additional problem? (be it some sort of telogen effluvium etc)

Thanks :)

Block Quote

The basis of good clinical medicine is to establish metrics (measurements) that give baselines from where we started. If you take such measurements yearly, you will be able to document the degree of thinning and this will help in the diagnosis.

Your story is not one that I hear too often, but to give you any insights I would have to examine you, take a good history from you, take bulk and miniaturization measurements of your scalp (sides and back, as well as front and crown). I can say that the back and sides of the head should not be decreasing in density, but only after you are examined can I do a better job of answering your questions.

Tags: hairloss, hair loss, density


Is it normal for hair volume to be less dense on top of your head than the lower back of head / neck area if you still have a full hair line up front above your face?

Block Quote

On a non-balding person the hair density is similar throughout the scalp, but there are areas where the density may be lower, like the sides of the head (above the ears).

Only the area in the back of the head (a 2 1/2 inch area) is considered permanent, as shown in the hair that remains in the Norwood class 7 pattern.

Tags: density, hair growth


Hello Rassman! I was just wondering where you got your degree?

I was also wondering how many hairs per square cm you would (theoretically) need to achieve the illusion of 100% density. 50%, 75%, 90%? Generally speaking of course.

Block Quote

Well, if an average Caucasian male has 200 hairs per square centimeter, and 50% of this density can be perceived as normal density, you can say 100 hairs per square centimeter can achieve the fullness. But it really all depends on your hair color, skin color, hair length, hair texture, hair style, etc.

For example, if you have 100 hairs per square centimeter and you have black hair on white skin with a short, straight hair cut, it will not even look close to a fullness enjoyed by someone with 25 hairs per square centimeter, but with black hair, dark skin and long curly hair. My point is, to achieve the maximum illusion of density, it isn’t just strictly about the numbers. Hair color, character, and style are also very important factors.

As to your first question — all of the our resumes can be found here.

Tags: density, hair transplant, hairloss, hair loss


Hi, what countries are the best for hair transplant? Trying to debate whether to find HT center in india or go abroad. Cant seem to find one here and its not easy getting centers to let us interract with patients as most patients want their confidentiality.

Also, in your website you mention it may take about 6000 hairs for a class 6 to get coverage. Does this mean full dense coverage?

Block Quote

I would be biased to say the best hair transplant surgeons are in the United States as a whole, but I am sure there are great doctors spread out all over the world. Look at the patient results and meet patients. Most patients do want confidentiality, but we have open house events every month where past patients come in to meet with and talk to prospective patients… so it’s not impossible to find live examples if the patient is really pleased with the work. With an ‘open door’ policy, that means that anyone can come in, even if there were patients who may not be pleased with their results. In 20 years of doing open house events, there has never been an unhappy patient showing up at our ‘open house’ events.

As for the second question — you will never get a completely full dense coverage with ANY hair transplant. It is mathematically impossible! Hair transplant surgery is basically moving your existing hairs around, so the density will never be full as it once was. For a Norwood 6 patient to get good coverage, about 6000 grafts is what is typically needed. Sometimes more, sometimes less. It also depends on many variables such as your hair texture (fine, medium, coarse), hair character (straight, curly, wavy), length (long, short), color contrast (between hair and skin color). These subtle factors all contribute to the results of a hair transplant. So while we strive to create the illusion of full density, it simply can’t be as full as it once was because those hairs are gone.

Tags: hair transplant, hairloss, hair loss, density, hair restoration


Dr Rassman,

I’m a Caucasian 27-year-old male with zero known family history of MPB. However, I’ve lost some hair on the front of my head, and crown miniaturization was detected — meaning that down the road, I could have a serious (Norwood 6?) pattern. I started taking Propecia and hope it can hold onto my hair for 5+ years.

That said, I already need a transplant. (A “conservative” well-regarded doctor recommended 1400 FUT.) I understand the need for a Master Plan and to not run out of donor hair too early. However, it’s very important to me to not be viewed as balding as a young man (I’m single and haven’t firmly established a career.)

I have fair skin and dark brown hair. Luckily, I’m blessed with wavy hair, donor density 2.3, that people commonly describe as coarse and thick. So, I’m wondering, how big of a transplant could I do now for the front of my head, and still leave enough donor hair for future loss? Could I transplant 2000-2500 grafts without worry? I imagine other patients might be in a similar situation to me.

Thanks so much.

Block Quote

Everyone is different. A 2.3 density suggests you have more hair in the donor area than many people, and with coarse hair you may be able to cover an extensive pattern. But for those with fine hair, it may not be enough to cover a class 6 or 7 balding pattern. I have many patients who have had more that 6500 grafts and most of them get quite depleted. A few of these patients have gone to 10,000+ grafts like this man, and although he could have passed the 10,000 graft number, he got realistically what he needed.

Tags: hairloss, hair loss, hair transplant, donor density


If an unlimited supply of donor hair were available, could transplant surgeons give a patient the 200 hairs per cm squared that the average human head has or would a new tool smaller than the .5mm tool im aware need to be created to achieve this look?

Block Quote

I suppose you can achieve 200+ hairs per cm squared (which is about the average for a non balding Caucasian male), but I find most people who are obsessive with hair per square centimeter don’t understand the full story and are mislead by all the discussion groups on the Internet.

You can have 100 hair per cm squared and still look like someone with 200 hairs per cm squared, as this is not a numbers game. Furthermore, hair transplant is NOT about the numbers and density. It is about the art of creating a natural looking hairline with minimal number of hairs you harvest.

With respect to graft survival, there may be some issues of the grafts surviving such close packing in ONE surgery. Now 200 hairs in a square centimeter is possible with multiple surgeries to the same area… but again, numbers do not translate to how it looks overall.

Tags: donor supply, hairloss, hair loss, hair transplant, dense packing


Hello dr rassman,
I did 1000 grafts FUE hair transplant one year ago, which was my biggest mistake in my life from 1000 grafts half of them didnt grow back , my donor area damaged considerably, my density in donor area was 85 grafts in 1cmm before surgery now its gone to 55 grafts in 1cmm , i calculated approximate 2500 grafts been damaged. dont you think FUE is a basic method and must be banned?

Block Quote

Swiss cheeseI’m sure the donor impact of follicular unit extraction (FUE) is rarely a subject discussed by many of the doctors doing this procedure. When the donor area has a below average density, the impact on the donor area is very significant and it may appear to look like Swiss cheese. When the density is high, this is not a problem.

Some doctors and patients seem to think that FUE is the answer to the ideal method of harvesting, but your example shows that it is not. Of course, it is possible that in getting out 1000 grafts, 2000 punch holes were made, but as I was not there, this is only speculation about a doctor that has perhaps not mastered the process. Damage to the donor area does occur with FUE, the question is just how much damage occurs in the hands of a skilled FUE surgeon.

Tags: fue, follicular unit extraction, hair transplant, surgery, hairloss, hair loss


I was reading this ‘Understanding Density’ article [PDF file] and it states that thinner ‘see-through’ hair has a density of about 20 cm2. It also says that areas with a pre-op density of 20-25 FU/cm2 could achieve a post-op density of 40-50 FU/cm2.

Then, in the ‘Determining Number of Follicular Units’ article [PDF file] on the same web page, it says that: with a pre-op density of 20 FU/cm2 and a transplant of 20-25 FU/cm2, a post-op density of 40-50 FU/cm2(20-25 FU/cm2 x 100 cm2 area) could be achieved with a total of 2000-2500 grafts.

I’ve had 2 transplants to the frontal half area as shown in the picture in the article, but I still have a ‘see-through’ appearance to some degree. My doctor has confirmed the 20-25 cm2 density was the goal, although it was never made clear to me that was his intention. Anyway, I’m assuming I have about the 20-25 cm2 density and I’d like to have another procedure to increase the density to 40-50 cm2. So, based on all this I’m estimating that I should get 2000-2500 grafts in my next procedure.

My question is: Do you agree with the info presented in these articles and do you think this is an accurate way to calculate how many grafts are needed? Also, are there methods/tools a doctor should be using to check scalp laxity and density to help with determining what can be harvested for another procedure?


Block Quote

CalculatorA hair density of 30-50% can produce a good look depending upon the coarseness of your hair and the color contrast of your skin and hair color. I have never believed that a hair transplant should bring you to 70% of your original density. The difference between people, based upon color/contrast and the coarseness of the hair, can be dramatic. A return of 50% of the original density in a person with fine hair will have a more see-through look than a return of 25% of the original density if the hair is coarse. So you see how difficult it is for me to understand your situation as the blanks (color/contrast and coarseness) are not filled in for me to include in the assessment.

The calculations are easy. The original density in a person with “average” hair density is hair is 2.1 hairs per mm square. That amounts to 1250 hairs per square inch (or 650 follicular units per square inch). You need to know the area we are talking about to do the calculations correctly, yet that is not really the answer as the variables which are not included will dictate the presence of a see-through appearance.

Tags: density, hairloss, hair loss, hair transplant, calculation


Hi Dr. Rassman,

Excellent blog. I read it every day and would love to add my question to the plethora of information available.

I have a question about donor supply. I of course understand that when it comes to strip harvesting, you can only cut out so much of the skin, and that only some of the hair at the back, below a certain line, is permanent. But I’d like to know why after using up all the available donor hair with reference to what you can get with the strip-cup method, you can’t go in and take more grafts via the FUE method. There is still plenty more permanent hair at the back and although it might be too low to cut into because of the nerves and muscles, using tiny punches to get it out I’m guess wouldn’t have negative affects.

Thinning out the sides too would I think also have the advantage of not only providing more donor hair, but it would also make the transplanted area not look as thin in comparison since you’re making this “thick” permanent zone thinner.

With doctors performing FUE where ever there is hair, even body hair, I’d like to know why you can’t just go after more permanent hair that you still have in the back of your head and on the sides.


Block Quote

Doing a strip harvest for the first hair transplant surgery and a follicular unit extraction (FUE) at a later time is generally not advisable, as you limit the donor density with the FUE. Essentially, you’re asking why doctors don’t try to thin the donor area as much as possible, but for many people having the sides and back of the head looking sparse would also be a problem. Then again, everyone is different and I would rather not make a rule without knowing your situation. If you start with strip harvesting, you should finish with strip harvesting if you go for another procedure.

Tags: hair transplant, hairloss, hair loss, density, laxity, fue


Page 2 of 712345Last »

Valid CSS!

HTML 5 Validated