Follicular units and hair transplant
By Prof. Dr. Soner Tatlidede 2021-11-02
What is a follicular unit? If you are considering a hair transplant, terms such as “follicular unit”, “hair follicle”, “implant” or “graft” are now probably familiar to you; but, do you know its real meaning? Can you distinguish them correctly? Do you know its function and its importance when performing a hair transplant?
We have noticed that, when our patients contact our clinic asking about the cost of a hair transplant, they usually do not make a clear distinction among these concepts, which are essential when explaining the entire hair surgery process. Therefore, in this article we want to clarify all these terms, and explain their importance when getting hair implants.
What is hair follicle unit?
To clarify concepts, let’s say to begin that the term “graft” is often used in the field of hair surgery to refer to each of the follicular units that are transplanted from the donor area to the recipient area, when a hair transplant is performed with the FUE technique. But, what are follicular units? A good follicular unit definition is that it’s a set of follicles contained in a single group or unit. The structural, or pilosebaceous unit of each hair follicle consists of the hair follicle itself, an arrector pili muscle, and a sebaceous gland (see picture above); however, follicles are usually not alone, but forming groups or 2 or more follicles.
Therefore, when we talk of a hair follicular unit, we are referring to each one of the grafts that are extracted from the donor area, and that can actually contain several hair follicles: 1, 2, 3, or 4 hairs is normal, but there are also those that contain 5 or 6 hairs ... even there are some cases – not very common - in which a single follicular unit contains up to 7 hairs. The number of hairs per follicular unit depends on several factors, such as race, age, or the area of the body where they grow.
The number of hairs contained in each follicular unit, will determine precisely the hair density; for example, blond people are those with a higher hair density, having up to 150,000 hairs on scalp, while in redheads their number is reduced to about 90,000 hairs: this means that in blonde people hair density is greater because they have more follicular units with multiple hairs.
Regarding race, and according to studies, Asian people have the lowest hair density, with an average of only one hair per follicular unit, while in black people it is the double, and in Caucasian people increases to 3 or 4. On average, human beings have between 120 and 260 hairs per square centimetre.
What is a follicle?
OK, now we know what the follicular unit is... But then, what is a hair follicle? A hair follicle, also simply called follicle, refers to the structure under the skin – including the hair root - from which a hair grows. Each follicle generates a hair... a that’s why these two terms are often mistaken. This means that it’s possible to say that a hair follicular unit can contain several hairs... or several follicles, too.
Let's say to clarify concepts that a follicular unit is like a bag, within which there may be several follicles or hairs. The function of a hair follicle is therefore to serve as a structure or container for the stem cells that will originate a hair, which at the same time settles on the follicle in which it is originated. In fact, this function is what makes follicles one of the most active and dynamic structures of the entire human body.
Let's offer an example to make it more clear: when, a few weeks after a hair transplant, many patients suffer the so-called shock loss, what falls out is actually the hair, the visible part of the follicle... But follicular units, and follicles within, are still there... and they will generate new hair again.
Why is so important to know the difference between follicular unit and follicle?
As we have seen, follicular units, follicles and hairs are terms that are often confused; for example, it is quite common to hear or read that a patient got a hair transplant with grafts that had 2, 3 or 4 hairs “in a single follicle”... but actually, this is incorrect: it should be said 2, 3 or 4 hairs ”in a single follicular unit.”
But, beyond its meaning, knowing the difference between follicular units and follicles is very important if we are thinking of getting a hair transplant, because the result of the intervention will depend on it; but also, to avoid any fraud or hoax by the clinic performing the operation. Just an example: it´s usual to see ads by hair clinics offering to implant 5,000 follicles or more in a single session... But of course, this does not amount to 5,000 follicular units...
Let’s see it with another example: imagine that a clinic wants to stand out before another competitor that offers 5,000 follicular units in a single session, promising then to implant "7,000 follicles in a single session" for the same price... Sounds good, right? But if we take into account that, in a Caucasian person, each follicular unit contains on average 3-4 hairs, actually the 1st clinic is offering us to implant... just between 1,750 and 2,300 follicular units!! Now it does not seem such a good offer anymore, does it?
This is one of the main reasons that make it essential to distinguish between follicular units and follicles. Going back to the previous example, it is not the same for a clinic to offer us a price for implanting 80-100 follicular units per cm2 (adequate to achieve a good hair density)... that for implanting 80-100 follicles per cm2, since this last option would leave us with a very poor hair density, forcing us to a second hair transplant.
Thinks to consider in follicular unit grafting
Know the difference between these two concepts is not only important, since then none can deceive us with fake advertising and tricky offers; it is also necessary to understand correctly when surgeon explain us how many follicular units should be extracted from the donor area, what is the capillary density that we must achieve to get a natural-looking hair, or what is the price per grafted follicular unit that offers us the clinic in question.
Another essential information is the number of follicular units that can be extracted from the donor area, since this number varies in each patient and will determine to what extent it is possible to recover lost hair, or to achieve the appearance we are looking for. In addition, it is very important for the medical team to perform a proper diagnosis and analysis to establish the limit of units that can be extracted from the donor area... or otherwise, it could be irreversibly damaged.
All these factors related to follicular unit must be taken into account to guarantee the success of the surgery. But, first and foremost, the key is to go to a trustworthy clinic: not that offering the most attractive advertising, but rather a professional and experienced team. Clinicana is the best hair transplant clinic, because we have the best hair surgeon in Turkey. Request a free consultation, and ask for a free, no obligation estimate for your hair treatment.
