Hair Transplant Donor Area

Article written by Dr. Blake Bloxham 

When it comes to hair transplants, the hair transplant donor area is everything. If a patient does not have a “good donor area,” they can’t have a good surgery. This is because a hair transplant procedure is really just a “moving” procedure; hair transplant doctors simply take follicles immune to hair loss from the donor area – on the sides and back of the scalp – and move them to the recipient area. Once they fully anchor, these new grafts remain immune and never fall out. 

Why does this happen? Because the follicular unit grafts were taken from the “safe” donor area. If a patient does not have adequate, hair loss immune grafts in the safe donor area, there is nothing to move and a transplant cannot be executed. 

So, whether you’re considering Follicular Unit Extraction (FUE) or Follicular Unit Transplantation (FUT), understanding the importance of the donor area is crucial. In this article, we’ll explore what the donor area is, how many grafts it can safely provide, the risks associated with a poor donor area, regrowth potential, post-surgery care, scars and recovery.

Are you wondering if you have “good” donor area? If so, read on to find out. 

The “donor area” refers to a region on the sides and back of the scalp containing hairs immune to genetic male hair loss (androgenic alopecia). These follicles lack receptors for “DHT” or dihydrotestosterone – the hormone responsible for hair loss in genetically susceptible patients (Unger, et al., 1994). 

Definitions of what constitutes the true “safe” donor area vary. Dr. John Cole defines the donor area, rather objectively, by 203 square centimeters of the occipital (back) and parietal/temporal scalp (Kumeresan et. al., 2018). Dr. Jae Park has used the bottom of the crown “whorl” as an anatomical marker to define the safe donor area (Kumeresan et. al., 2018). However, the widely acknowledged safe donor designation came from Dr. Walter Unger in 1994. 

Dr Unger, a widely respected hair transplant physician and researcher, studied the issue extensively and used hair counts, anatomical markers, and mathematical measurements to define the gold-standard safe donor area in hair transplant patients (Kumeresan et. al., 2018). Unger’s model is shown below: 

While definitions and images are great, the safe donor area is really defined by one thing: the area of the scalp containing follicles which are permanent and will remain permanent after transplantation. 

But how many follicular units (grafts) are available in the safe donor area? Do some patients have more than others? Are some grafts “better” than others? What happens if a patient does not have enough? 

The total amount of “hair” in the safe donor area is not as important as the number of grafts that can be safely harvested. This number varies depending upon the density of the hair, the scalp laxity (stretch/movement), the size of the patient’s scalp, and the harvesting method used – FUT or FUE. Dr. Unger explored this issue as well and determined there are roughly 4,000 – 7,000 available grafts to be safely harvested in the donor area (Kumeresan et. al., 2018). This number presumes a fairly standard surface area but differences in hair densities. 

Drs. Ron Shapiro and David Josephitis found that donor harvesting methods affect available grafts numbers as well. Specifically, they found more grafts can be removing using FUT followed by FUE compared to FUE harvesting alone (Shapiro & Josephitis, 2019). It stands to reason that patients with greater scalp laxity also receive more grafts than patients with tighter scalps when utilizing FUT. 

But what about patients who only want FUE surgery? How can they obtain high graft numbers for a standard safe donor area? 

Unlike FUT, FUE causes a decrease in donor density. This is because FUE involves the direct removal of hairs without any removal of skin or closure of wounds. Reducing the number of hairs without reducing the skin surface area creates a generalized thinner appearance. Only around 30-50% of grafts can be removed before the donor area appears too thin. This means you can only remove a small amount of hair from the safe donor area using FUE. 

To get around this problem, some clinics harvest grafts from outside the defined safe donor area in regions they call the “expanded” or “safer” donor area. These are areas close to the safe donor, but not ones proven to contain permanent grafts. This means these grafts may fall out or shed after they are transplanted. It also means the hair around where they were taken from may thin as well – exposing the FUE extraction scars. 

The alternative is harvesting greater than 50% of the grafts from the true safe donor area. This is called “over harvesting” and creates a thin, patchy appearance which cannot be camouflaged. It is something all patients should try and avoid. 

Due to these potential issues, all patients considering large FUE sessions should discuss “donor management” and safe harvesting with their hair transplant doctors. 

A poor donor area refers to a region with insufficient hair density or quality for successful harvesting. In cases where the hair in the donor area is too thin, weak, or sparse, it may not be suitable for transplantation. Additionally, individuals with certain medical conditions, previous scarring, or extensive hair loss may have a limited donor area.

Attempting to harvest hair from a poor donor area can lead to unsatisfactory results, including unnatural-looking “islands” of hair surrounded by bald areas and noticeable scars or thinning in the donor region.

Patients must make sure their donor area is evaluated before surgery. It also must be evaluated by an experienced and ethical hair transplant doctor. Patients must avoid surgery or have very realistic and described expectations if they have a poor donor area. While it is an unfortunate reality, it’s much better than undergoing a procedure that is doomed to fail.

Patients with fewer grafts in the donor area are eager to know if the follicles regrow or regenerate after removal? If a graft regrows once it is extracted and reimplanted, does it matter how many are back there to begin with?

While this type of regeneration would allow for large number of grafts even in patients with low donor densities, it is unfortunately not what occurs. Remember, a hair transplant procedure is really a “moving” procedure. Follicular unit grafts are removed from the safe donor area and implanted into the bald or thinning regions. A successful transplant requires the complete removal and reimplantation of these follicular units. That means all of the graft will be permanently removed from the donor area and will not grow back. Once it’s taken from the donor, it is gone.

There are some exceptions like when grafts are partially cut or ripped during failed FUE extractions; these can often grow back in the donor area. However, grafts successfully removed and reimplanted from the donor area are just that: removed. Once they are gone, they are gone.

Patient should not expect any sort of regrowth or regeneration in the donor area. If these grafts do not grow back, will there be visible scarring from where they are taken from? If so, what will this look like?

• FUE (Follicular Unit Extraction): In this technique, individual follicles are removed one by one using a number of small (typically less than 1mm) punch tools. The donor area will have tiny, dot-like scars where the follicles were extracted. These small scars are usually very subtle, especially when a smaller number are done and they are appropriately spread throughout the safe donor area. 

• FUT (Follicular Unit Transplantation): FUT involves removing a strip of scalp from the donor area, which is then stitched closed. The result is a linear scar that runs across the donor region. While the scars are typically thin and can easily be concealed by longer hair, it may be more noticeable in individuals who prefer short hairstyles.

Note: Read a recent on article on Verteporfin and hair transplants and the impact on scar visibility. 

Both FUT and FUE surgery involve recovery in the donor area. This typically depends on the method used and the individual. Generally, the wounds in the donor area are fairly well healed within a few days to a few weeks. However, final “maturation” of these wounds (like all wounds) can take up to 12-18 months. Common symptoms experienced during this healing period include: 

• Swelling and redness: It’s normal for the donor area to be red and slightly swollen for a few days post-surgery.
• Scabbing: Small hair transplant scabs will form in both FUE and FUT procedures, which usually fall off within 7-10 days.
• Itching: Some mild itching may occur as the donor area heals, but it’s important to avoid scratching, as this can disrupt the healing process.
• Pain and discomfort: Patients may experience mild pain or tightness in the donor area, particularly in FUT procedures where a strip is removed. Pain medications and topical treatments can help alleviate this.

Proper care of the donor area is essential for a smooth recovery. After surgery, you should avoid sleeping directly on the donor area for the first few days to minimize pressure and reduce the risk of damaging the grafts or incisions. It’s recommended to sleep in an elevated position with your head propped up by pillows to reduce swelling. Each clinic has their own instructions for sleeping after surgery; these should be followed carefully. 

The donor area typically should be washed starting 24 hours after surgery. It’s important to keep this area clean and free of excessive scabbing. This helps reduce inflammation, pain, and risk of infection. 

With FUT procedures there will be stitches or staples in the donor area for 7-10 days. These may need to be cleaned more thoroughly and some clinics may want ointment or creams applied to the area. Others will not. The stitches or staples will also need to be removed 7-10 days after surgery. 

There may be some longer activity restrictions with FUT. This includes limiting certain exercise activities which place excessive stress and strain on the healing scar. However, not all clinics recommend this and individual post-operative instructions must be followed closely. There are typically not as many post-operative restrictions after FUE surgery. 

But a picture is worth a thousand words, right? Here are some images of FUT and FUE donor “before and after” provided by Dr. Blake Bloxham: 

References: 

Kumaresan, M., et. al. (2018). Controversies in Hair Transplantation. Journal of Cutaneous and Aesthetic Surgery. Volume 11; Issue 4; October – December. 

Shapiro, R., Josephitis, D. (2019). A Side-By-Side Study of FUT vs. FUE Graft Availability in the Same Patients and its Implications on Lifetime Donor Supply and Management. Hair Transplant Forum International. Volume 29; Number 5; 178-185. 

Unger W, Solish N, Giguere D. Delineating the “safe” donor area for hair transplanting (1994). Am J Cosmet Surg;11:239–43.