Clinical Dermatology Review

: 2022  |  Volume : 6  |  Issue : 2  |  Page : 80--87

Hair transplantation: A brief review

T Muhammed Razmi1, Kiruthika Subburaj2,  
1 Department of Dermatology, IQRAA Aesthetics, IQRAA International Hospital and Research Centre, Kozhikode, Kerala, India
2 Department of Dermatology, PGIMER, Chandigarh, India

Correspondence Address:
T Muhammed Razmi
Department of Dermatology, IQRAA Aesthetics, IQRAA International Hospital and Research Centre, Kozhikode - 673 001, Kerala


Hair transplantation is a safe and effective treatment option in patients with male and female pattern hair loss. Alopecia leads to a lack of self-confidence and social withdrawal in young patients when compared to their peers with good hair density. Patient selection, counseling, and planning the procedure have equal importance as that of the hair transplantation surgery itself. Follicular unit transplantation (FUT) and follicular unit extraction (FUE) are the two commonly used techniques of hair restoration. In FUT, a strip of tissue is excised from the occipital donor area resulting in a linear scar. Whereas in FUE, the scarring can be avoided as small individual follicular units are harvested and transplanted in the recipient area. FUE is emerging as a most opted hair restoration procedure in patients with patterned hair loss. This review elaborates on the procedure of FUE in brief and gives a detailed step-by-step guide for performing the procedure.

How to cite this article:
Razmi T M, Subburaj K. Hair transplantation: A brief review.Clin Dermatol Rev 2022;6:80-87

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Razmi T M, Subburaj K. Hair transplantation: A brief review. Clin Dermatol Rev [serial online] 2022 [cited 2022 Sep 26 ];6:80-87
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With the advent of selfies, group video calls, and social media platform self-made videos, the look of the hair has become important among individuals of all age groups. Hair loss associated out-patient consultation is increasing. Hair loss is estimated to affect about 85% and 40% in males and females respectively.[1] The most common cause for hair loss is androgenic alopecia (AGA), an androgen-sensitive pattern of hair loss that affects both men and women.[1] Various medical modalities are available for AGA, but with suboptimal results and lesser patient satisfaction. Moreover, the patients are unhappy with the longer duration of therapy and the need for repeated physician visits, if it is for a procedure. Hair transplantation, on the other hand, has a significant outcome in terms of transforming a bald scalp into that with lush hair growth.

 Planning of Hair Transplant Surgery

A hair transplant is an elective procedure, and the surgeon usually gets enough time for proper planning. Planning starts from the initial patient consultation itself. During the initial interview, the doctor has to comment on the number of grafts required by assessing the hair quality, extent of alopecia, and patient preference. Age, medical history, family history of alopecia, facial features, and hair characteristics (caliber, texture, color) all may affect the outcome. Since the transplant outcome largely depends on the number of grafts used, this has much significance from the surgeon's perspective. At the same time, since the transplant cost also depends on the number of grafts used, it has bearing on the patient part also. Moreover, the initial interview helps to ascertain the patients with contra-indications and to avoid nonideal candidates.

 Contra-Indications and Nonideal Candidates

A thorough preoperative evaluation is essential to exclude those patients with contraindications to hair restoration surgery [Table 1].{Table 1}

If not excluding, one has to learn to modify the plan of surgery based on the patient's characteristics. The below text roughly explains the approach to such “nonideal candidates,” [Table 1].

A young patient with unrealistic expectations is a common scenario in a hair transplant consultation. Comparing to their peers with full head coverage, these patients tend to request denser coverage and prefer a low hairline. Since the AGA is progressive and the donor hairs are finite, the surgeon must counsel the patient regarding these factors, [Figure 1]. A minimum quiescent period of 6–12 months is recommended before doing a hair transplant in patients with inflammatory skin conditions such as alopecia areata and lichen planopilaris.[2] Patients with hypertension tend to bleed more during surgery and have a possibility of poor graft uptake, hence, it is recommended to control hypertension before the procedure. Diabetic patients have poor peripheral circulation that may lead to delayed wound healing. Hence, the procedure should be done in multiple sessions gaped at least by 6 months. Those with moderate cardiac risks or prior bypass surgery should undergo smaller sessions. Risks due to local anesthesia are more in these individuals, hence, judicious use of epinephrine, use of ropivacaine over bupivacaine, and the surgery under cardiopulmonary rescue support over solo clinic should be preferred.[2]{Figure 1}

 Address Treatable Causes and Conditions

Associated telogen effluvium should be identified and treatable reasons like iron deficiency anemia and hypothyroidism should be corrected. In female pattern hair loss (FPHL), associated hormonal imbalance like polycystic ovary disease should be managed medically or by lifestyle measures. Post hair transplant crusting may be profound in patients with scalp psoriasis and severe seborrheic capitis and may hamper the graft uptake. These diseases should be controlled by medical modalities before transplant.

 Hair Transplant after COVID-19 Recovery?

The duration of the gap before undergoing a hair transplant procedure is a pressing concern in this COVID era. There are two major concerns in these patients. One is the possibility of prolonged viral shedding. People with mild to moderate COVID remain infectious only for up to 10 days. Recent CDC updates recommend symptom-based over test-based strategies to end isolation in these individuals. More severe to critical illness or severe immunocompromise individuals likely remain infectious longer than 20 days after symptom onset. For adults who are severely immunocompromised, a test-based strategy could be considered in consultation with infectious diseases experts.[3] This is regarding the theoretical possibility of viral spread during the procedure, and the hair transplant is not a practical choice at this period.

The major concern is the possibility of post-COVID complications in the recovered patients. Owing to the increased chance of airway hypersensitivity following COVID-19, some experts suggest delaying surgical procedures by 4–6 weeks, if possible.[4] Even though hair transplant surgery doesn't usually require intubation, post-COVID thrombotic state/vascular complications and malaise may compromise the postprocedure recovery period. Such systemic complications like multisystem inflammatory syndrome in adults[5] are reported to occur up to 3 months after COVID-19. Moreover, post-COVID telogen effluvium may hamper the graft uptake. Hence, it is prudent to wait at least 3–6 months after COVID-19 recovery before undergoing hair transplant surgery.

 Clinical Assessment during Hair Transplant Interview

Assessment for the cause and extent of alopecia is important during the initial interview. Inspect the scalp for any patchy loss of hairs or other cutaneous features like scaling, follicular plugging that suggest inflammatory scalp conditions. Hair pull test, trichoscopy, and in rare cases scalp biopsy will also help in this aspect. Wetting or parting the hairs will help in the assessment of the extent of alopecia. The donor area follicular unit (FU) density, hair density, and hair thickness are the most important parameters to be evaluated (using a micrometer). Patients with normal-to-high FU density (>65 FU/cm2) and thick hair (50–60 μ) are considered good candidates while patients with diffuse hair loss, low FU density (40–50 FUs/cm2), and donor hair miniaturization (20% miniaturized) are poor candidates. Coarse hair and curly hair will have better coverage compared to fine hair and straight hair.[6]

Initial interview should also include a psychological assessment of the patient to exclude body dysmorphic disorder candidates. An expert psychiatry/psychology referral may also be reported.[2]

 Preoperative Instructions

Baseline blood pressure and lignocaine allergy should be evaluated preferably in the initial visit itself. Baseline investigations include complete hemogram, liver and renal function tests, coagulation workups, and viral markers. In patients with cardiac comorbidities and patients aged more than 40s, an electrocardiogram can also be advised.

Patients are advised to stop minoxidil at least 10 days before the proposed surgery to avoid increased bleeding. Advise patients not to wear T-shirts or inner vests on the day of surgery. Head wash with betadine scrub is advised on the day before and the morning of the surgery.[7]

 Hair Transplant Surgery

Hair restoration surgeries, as they are more aptly called, were pioneered by Dr. Norman Orentreich towards the end of the 20th century. He successfully used 6–12 mm punches to create grafts in the occipital area. These grafts when transplanted into the bald area grew successfully. This simple procedure heralded the era of hair restoration surgery. He established the concept of “donor dominance” in pattern hair loss and transplanted hair grafts from the occipital region to the bald area using 6–12 mm punches successfully.[8] Another breakthrough in the field was the concept of “follicular units” by Dr. Headington in 1984. It states that hairs do not occur singly but as “follicular unit” composed of 1–4 terminal follicles [Figure 2], sebaceous gland, arrector pili, perifollicular vascular plexus, nervous supply, and perifollicular collagen.[9]{Figure 2}

Several modifications based on these concepts are used in hair restoration surgeries and are mainly classified into:

Follicular unit extraction (FUE) technique andFollicular unit transplantation (FUT) technique.

 Follicular Unit Transplantation Technique

A strip of graft of about 10–20 cm long is taken from the occipital area of the scalp, donor area, [Figure 3]. Then, individual FUs are dissected from the strip under magnification. These are, then implanted into the preprepared slits on the “recipient area” (frontoparietal region) of the scalp.{Figure 3}

The advantages of the FUT technique over the conventional method are:

Minimal bleeding from the donor areaThe single strip provides 1000–1500 graftsPlacement of individual FU in each slit gives a denser packing and cosmetically better results.

The various disadvantages of this method include:

Skill-based methodRequire careful handling of delicate hair folliclesNeeds microscopic dissection of hair units, hence time-consuming and laboriousMore expensiveThe donor area linear scar may widen and may lead to poor cosmesis.Postoperative pain is more.

 Follicular Unit Extraction Technique

In the FUE technique, the FU are individually harvested from the donor area [Figure 4] and placed onto the recipient's frontoparietal scalp. Under aseptic conditions, ring block anesthesia of occipital and frontal region is given, the latter can be given before graft insertion, followed by tumescent infiltration of donor and recipient area with 30 ml 2% lignocaine mixed with 5 ml 0.5% bupivacaine, 30 ml normal saline (NS), 0.5 ml adrenaline (1:1000), and 1 ml triamcinolone 40 mg/ml in a normal adult patient. Once desired anesthesia is achieved, the FU are harvested.[10] Steel punches of diameter 0.7–1.2 mm (commonly 0.8–0.9 mm) are used for this purpose. The graft extraction can be facilitated by devices custom-made handheld punches or motorized devices. The harvested FU may be transplanted immediately onto the recipient area, into preformed slits, upon extraction which is known as the direct hair transfer method, thus decreasing the “out of the body time” for the harvested grafts, which is theoretically said to be of some beneficial effect in graft survival. The other method is to store the harvested grafts in a medium, for example, NS (0.9% NS), chilled NS, hypothermosol A solution, ATP enhanced media, or platelet-rich plasma (PRP), before implanting them into the recipient site. The graft survival rate in such a situation is dependent on the temperature of the holding solution, out-of-body time, minimal handling of the grafts, and the use of biostimulus. Poor graft survival may occur due to dehydration, transection, blunt trauma, and ischemia-reperfusion injury. Reducing the “out-of-the body time” will be crucial to improve graft survival. Chilled NS (1°C–4°C) is a better holding medium for graft survival as compared to NS.[11] Chilled grafts seem to tolerate crushing trauma better than grafts maintained at room temperature. There is minimal evidence on the optimal holding solution. Limmer[12] performed an in vivo out-of-body time study using chilled NS with FU grafts. The results were: 2 h, 95%; 4 h, 90%; 6 h, 86%; 8 h, 88%; 24 h, 79%; 48 h, 54%. Limmer related a good “rule of thumb,” stating that the loss was roughly 1%/h. More studies are required to evaluate the ideal out-of-body time.{Figure 4}

 Graft Insertion

Extracted grafts are implanted into the recipient area either after creating preformed slits using forceps [Figure 5] or directly using implanter pens [Figure 6]. FU need to be held at the upper 1/3 rd region, thus avoiding damage to the bulb region (“no root touch” technique). Among the graft insertion techniques, Choi et al. devised the revolutionary method of using spring-loaded implanters to speed up the transplantation process.[13] The FU were carefully prepared and implanted using an implantation device. The grafts ideally should be flushed to the skin surface. Popped-up grafts may lead to a cobble stoning effect, and buried grafts may lead to a pitted appearance. Care to be followed to make this step atraumatic as far as possible. The various techniques[13] which can achieve the above principles are:{Figure 5}{Figure 6}

The “stick and place method” – here the creation of slit and placement of the graft is done simultaneously which decreases the out-of-body time. In the case of direct implantation, the needles must be replaced frequently due to the loss of sharpness and have been associated with the popping of the graft and graft loss, especially when the grafts are placed close togetherCreating all the recipient sites at one time and then placing the grafts one by one. The physician's time is saved as they can plan the shape of hairline, density, direction, and angulation of implanted grafts. If premade sites are not made, then the grafts need to be implanted by the physician himself/herselfUsing implanter pens in which the grafts are inserted into the hollowness of the implanter device and the slit making and graft insertion takes place together. The advantage of this technique is minimal handling of graft but the risk of “distal hooking” and “bulb decapitations” is presentCreating all the recipient sites and then using an implanter to insert all the grafts together. The force required to insert the graft into the scalp is minimized because of premade site. As the skin is already incised, while inserting the implanter into the premade site, the lateral tension is less and thus popping is very less.

 Postoperative Care

Head bandages are given for donor area harvested wound. No dressing is given for transplanted grafts. Postoperative medication includes antibiotics, analgesics, anti-inflammatory agents, and antihistamines. Neovascularization of transplanted grafts takes 3 days, hence, regular application of NS wash is recommended for the initial nourishment of the grafts. Postoperative periorbital edema starts by 3–4 days and subsides by 7–10 days. Oral steroids, headbands, elastic adhesive dressing on the forehead, and lymphatic massage are advised to prevent this common complication. The dermal part of the transplanted grafts starts to dry up to black by day-2 and peri-graft serosanguinous oozing followed by crusting can be seen during the initial 10 days. Head wash with a mug of baby shampoo can be done after 3 days. We advise head wash from the clinic on day-10, to further remove these crusts [Figure 7]. Occasional hair shafts may also shed along with the crust, leaving behind the follicle root buried inside the dermis.{Figure 7}

 Patient Instructions

Patients are advised to sleep with their head-end elevated 15°–30° during the 1st week after surgery to minimize swelling. This can be achieved using a neck pillow. Strenuous activities like heavy lifting and bending at the waist must be avoided for 1-week postsurgery to avoid disrupting grafts. Ice can be placed on the forehead (not the implanted grafts) gently for 20 min every hour for the first 2–3 days to reduce forehead swelling. If there is any dislodgment of grafts, the patient is advised to bring them immediately to the office on saline-moistened gauze and based on the level of hydration of graft, re-implantation may be attempted, but the patient should be informed about the possibility of decreased viability of the graft. Minimal bleeding from the recipient sites is common in the first 1–2 days after surgery and should be managed with gentle pressure using clean damp gauze. Patients are advised to resume normal activity after 7 days, but in patients with tight scalps, minimal neck flexion for 4–6 weeks should be advised to limit stress on donor-site closure for FUT transplant.[14]


Initial 1–3 months are the period of shedding. Some people will develop shedding of nonharvested hairs from the donor area also. This may be due to overharvesting or increased usage of adrenaline in the tumescent solution. Buried hair roots start growing from the resting phase by 4th month. Appreciable hair growth, still without density, can be noted by 6 months and a satisfactory outcome can be seen by 9 months [Figure 8]. No significant hair growth from the buried roots can be expected after 1 year.{Figure 8}

 Postoperative Minoxidil, Platelet-Rich Plasma and Low-Level Light Therapy

The vasodilative properties of minoxidil have been hypothesized to enhance wound healing postoperatively. Minoxidil 5% has to be used twice daily in the recipient and/or donor area, beginning 5–7 days after surgery. However, there is the risk of increase in postoperative bleeding and scalp irritation. If there is irritation, a lower strength dose or decrease in frequency can be helpful. In case of irritant folliculitis with minoxidil, it should be stopped and a topical corticosteroid should be prescribed.[15] Plasma rich in growth factors (PRGF) technology has been studied for its efficacy as an adjuvant therapy for FUE surgery. The proliferation and migration of follicular cells were induced by the autologous growth factors. The integrity of perifollicular structures and extracellular matrix proteins improved with PRGF and also there was decreased postsurgical crusting, hair fixation period, inflammatory pain, and itching.[16] Uebel et al., studied a short series of patients comparing two areas of hair transplantation with or without PRP in the root of the grafts. About 20 grafts/cm2 were grafted in two areas of 2.5 cm2 each on the scalp. After a follow-up of 12 months, the area implanted with the PRP-enriched grafts revealed a higher follicle units survival rate as well as density.[17] In a study comparing the result of low-level light therapy irradiation with placebo in hair transplantation where the hairs were irradiated before transplantation, no significant difference between the groups regarding hair growth was noted (P > 0.8).[18]


FUE is relatively a safe procedure. However, rarely some serious complications can occur. Minor and common side effects include postoperative pain (up to 3 days), postoperative facial edema (subsides by one week), scalp folliculitis (up to 3 months), temporary paraesthesia of the scalp (up to 3 months), and donor area effluvium (starts by 1-month, subsides by 3 months and complete regrowth appreciated by 6 months). Close placement of slits or deep slits damaging vessels may lead to scalp necrosis which should be managed meticulously.

However, some serious complications need to be addressed vigorously. These include allergic reactions to lignocaine, lignocaine overdosage, and scalp cellulitis. Nowadays, with mushrooming of hair transplant centers doing surgery without following proper hygienic measures, and done by quacks, there are cases of atypical mycobacterial infections after hair transplant surgery. Most of these incidents are misdiagnosed and mistreated by underqualified paramedics, dentists, or alternative medicine practitioners until patients seek expert higher opinion [Figure 9]. Hence, there is an unmet need for dermatologist hair transplant surgeons who can easily diagnose such scenarios.{Figure 9}

 Theory of Safe Donor Zone in Follicular Unit Extraction

A safe donor zone refers to the area of the scalp with hairs less sensitive to circulating androgens. Hairs in this zone are less likely to be thinned in the future so that the transplanted hairs in the recipient site have predictable longevity. In practice, one can see AGA patients in their advanced ages having a stable zone of thick hairs. The safe donor site of the scalp lies in the mid-occipital region between the upper and lower occipital protuberances.[1]

 Hair Transplantation in Scarring Alopecia

Hair transplantation was first tried in traumatic alopecia even before it was introduced in those with AGA.[20] Hair transplantation in cicatricial alopecia has various challenges. The outcome of hair transplantation depends on donor hair availability, scalp laxity, location of the scar, and vascularity of the recipient site.[19] In primary cicatricial alopecia, the disease process and the activity are the major concerns. The results of hair transplantation have been found to be better in central centrifugal cicatricial alopecia (60%), morphea (85%), pseudopelade of brocq (60%), discoid lupus erythematosus (72%), and folliculitis decalvans (40%). In an unstable type of cicatricial alopecia, the active disease may spread to the donor as well as the recipient area and can compromise the surgical outcome. Undoubtfully in burnt-out cicatricial alopecia, hair transplantation is one of the desirable treatment options. A time period of 1–5 years (longer duration in cases like frontal fibrosing alopecia) of no disease activity is considered sufficient before doing hair transplantation in such cases. FUE is preferred over FUT. Apart from scalp hairs, beard and body hairs can also be transplanted. The donor and recipient area can be anesthetized by giving a ring block using lignocaine adrenaline mixture. Avoid adrenaline for tumescent anesthesia as it can further compromise vascularity. The graft density of 15–30/cm2 can be given depending on the vascularity of the recipient site. Pretreatment with oral pentoxifylline, topical minoxidil, and CO2 lasers of the recipient site was tried to increase the vascularity and has shown good results. Concurrent PRP treatment with hair transplantation can also be tried as it has shown better results than HT alone in AGA.[20]

 Follicular Unit Extraction Technique with Nonscalp Hair as Donor

In instances where the scalp donor reserve is poor, nonscalp hairs preferably beard hairs can be used. Poor donor reserve may be due to advanced grade of baldness or due to exhausted donor reserve owing to previous hair transplant procedures. However, body and beard hairs are different from scalp hairs in their thickness and growth rate and they have a shorter anagen phase. They have lesser and unpredictable graft uptake compared to scalp hairs.[21]

 Beard, Eyebrow, and Eyelash Transplant

Nowadays, hair transplant is employed for the esthetic enhancement of the beard and eyebrows. As in the recent crush for longer and thicker beards among youngsters, as well as the diversification of hair transplant services to overcome the competitive market of hair transplantation, the number of hair transplants for beard enhancement is increasing.[22] The technique is also used for the correction of leukotrichia due to vitiligo. Chatterjee et al. have used FUE for the correction of eyelash leukotrichia in vitiligo.[23] FUE can also be done postburn alopecia.[24]

 Female Hair Transplant

A female hair transplant is different from a male hair transplant. Here, hairs are not trimmed, the hairline has more rounded temporal peaks, and the transplant is planned with a wide base at the hairline with a tapering design posteriorly corresponding to the 'Christmas tree' pattern alopecia in FPHL.[25]


FUE megasession is described as transplanting >3000 grafts in a one-time surgery. Transplantation will be performed by a team of 1–2 surgeons and 4–5 assistants. Surgeons are dedicated to graft harvesting and creating slits, while three assistants will be dedicated to graft dissection and two assistants will be dedicated to graft implantation. Most of the hair restoration surgeons recommend harvesting only 50% of the donor density as more than that might lead to a visible decrease of hair density in the donor area. FUE megassession has the advantages of decreased frequency of surgery and patients with severe AGA are encouraged toward hair restoration treatment.[26]


Hair transplantation is considered to be an instant long-lasting remedy for patterned hair loss. Patient selection, counseling, and planning the procedure have equal importance as that of the hair transplantation surgery itself. FUT and FUE are the two commonly used techniques of hair restoration. In FUT, a strip of tissue is excised from the occipital donor area resulting in a linear scar. Whereas in FUE, the scarring can be avoided as small individual FU are harvested and transplanted in the recipient area. FUE is emerging as a most opted hair restoration procedure in patients with patterned hair loss.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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