What is the FUE Technique?

The FUE Technique, or Follicular Unit Excision, is a modern hair transplant method in which hair follicles from the safe donor zone on the nape and above the ears are excised individually typically with 0.7–1.2 mm micro punches in their natural units and transplanted into sparse areas. In today’s practice, the most commonly preferred punch size range is 0.8–0.9 mm; however, the final choice is made according to individual features such as hair shaft thickness, curl, and skin elasticity. Although the FUE Technique does not leave a linear scar, it is not completely scar-free; pinpoint impressions that are hard to detect with the naked eye may remain in the donor area after the procedure. In terms of terminology, the word “excision” is used instead of “extraction,” because the procedure is, in the literal sense, a cut-and-remove process.

Why are proper candidate selection and analysis critical?

The first step of a successful FUE Technique is measurable planning and proper candidate selection. For this, a pre-operative follicle analysis based on densitometry and trichoscopy is performed. In this analysis, the follicular unit (FU) density in the donor is counted per cm², the average hairs per FU is determined, hair thickness is evaluated in microns, and a miniaturization map is created. Although typical donor density varies from person to person, it generally ranges between approximately 60–100 FU/cm². Thanks to these measurements, the questions “how many grafts can be harvested, how many FU/cm² will be implanted where, and how will donor aesthetics be preserved?” are answered with figures. The borders of the safe donor area are defined to stay outside regions susceptible to androgenetic loss, thus reducing the risk of visible thinning. In expectation management, the goal is not to copy the original density one-to-one, but to achieve the optical fullness threshold which, in most people, can be reached even at roughly half of the original density.

FUE Technique by the numbers: Which densities are safe?

In planning for the FUE Technique, a few baseline numerical precautions are taken. In donors with average density, a safe single-pass harvest amount is approximately 10–15 FU/cm². In patients with thick hair shafts and favorable tissue conditions, this value may approach 20 FU/cm² in selected cases; however, the risks of visual thinning in the donor, “mottling,” and over-harvesting increase. In patients planned for multiple sessions, it is necessary to deliberately preserve at least 40–50 FU/cm² residual density in the donor. In the recipient area, a target density of 30–40 FU/cm² in a single session provides a natural look and high growth in most cases; “dense packing” at the 50–60 FU/cm² level should only be considered when good vascularization, thick hair shafts, and suitable tissue conditions are present. The average hairs/FU is in the 2.0–2.3 range; therefore, single-hair grafts are preferred in the first 1–2 centimeters of the hairline, while double and triple grafts are favored in layers requiring density, balancing both naturalness and fullness.

How is pre-operative planning done?

Planning begins with the evaluation of the Norwood classification, hair thickness and wave, hair-skin color contrast, and miniaturization distribution. Densitometric measurements are taken from at least three points along the occipital, mastoid, and temporal lines in the donor area; FU/cm² and the average hairs/FU are recorded and documented with standard photographs. Then the recipient area is calculated in square centimeters and a target density map is created for each sub-region: 30–40 FU/cm² at the frontal hairline, 30–35 FU/cm² in the mid-scalp, and 25–35 FU/cm² at the crown/vertex; at the crown, the slits are designed to follow the natural whorl. The graft requirement is shared with the patient using a clear formula: for example, if 35 FU/cm² is targeted for an 80 cm² area, then 80 × 35 = 2,800 FU are needed; assuming an average of two hairs/FU, this corresponds to approximately 5,600 hairs transferred. During planning, the use of anticoagulants, comorbidities such as diabetes and hypertension, a history of keloids, smoking habits, and concomitant skin diseases must be taken into account. Standard-angle photo records are taken before the procedure and the informed consent process is completed.

How should the team, room setup, and infection control be organized?
The success of the operation relies on a well-designed team workflow. The responsible physician, the harvesting technician, the graft sorting-counting team, the loaders and implanters, and the circulating nurse share duties. To shorten ex vivo time, a “multiple Petri” method is used: while one Petri dish is in the field, others are kept cold, and grafts are transferred in small bundles with a regular rotation. Grafts must never be allowed to dry; open-air time is limited to minutes. The sterilization chain, lot tracking of disposable materials, and instrument-consumable counts are indispensable parts of infection control.

Which technical details matter during donor harvesting?

Advancing the punch parallel to the hair exit angle and using a guard for depth control preserves graft integrity. The procedure consists sequentially of centering (scoring), dissection, and extraction steps. Manual or motorized systems can be used; in addition to sharp and dull punches, SAFE-like systems alter the risks of transection and “buried grafts.” The target transection rate is monitored intraoperatively with live counts and kept as low as possible; a practical target for most teams is in the 5–10 percent range. Instead of overly symmetric or band-by-band harvesting, a mosaic-style, diffusely distributed pattern is preferred. Avoiding the areas outside the boundaries of the safe donor zone—especially the lower nape and upper lateral areas—prevents visible thinning later on. Increasing punch depth more than necessary may raise dermal heat and trigger ischemia-reperfusion stress; therefore, angle and depth must be managed meticulously.

How are grafts preserved ex vivo?

Graft survival—i.e., holding—is decisive for outcomes. The order of principles is clear: shorten ex vivo time, keep grafts constantly moist, and establish the proper temperature-solution balance. For short waiting times, isotonic 0.9% NaCl or Lactated Ringer’s is sufficient. If the wait will be prolonged, keeping grafts cold at approximately 4–10 °C without freezing supports viability. Because dehydration can reduce graft viability within a few tens of minutes, grafts on the working table are kept moist with a saline “mist,” wet gauze is refreshed frequently, and grafts are not left exposed for long. For extended waits, there is data suggesting advantages to advanced solutions such as HypoThermosol and ATP that aim to maintain intracellular balance; however, since the effects of these products may vary with patient and process conditions, the core strategy remains shortening total time and maintaining hydration.

How do we standardize the cold chain and ice pack management?

The goal is to keep the solution temperature in the graft tray stable within the 2–8 °C range. For this, use a lidded, insulated container, a temperature probe or data logger, two sets of gel ice packs, LR/NaCl, and a rack that prevents the graft container from direct contact with ice. Temperature is recorded every 15–30 minutes; when it exceeds 8 °C, replace the ice pack or increase the amount of ice, and when it drops below 1–2 °C, reduce ice contact to avoid freezing. Under typical room conditions, changing the packs every 2–3 hours in medium-size insulated containers is often sufficient; however, since lid opening frequency and room temperature can shorten this interval, real-time temperature measurement is preferred over a fixed-hour rule. A two-tray rotation is implemented, and grafts are brought to the field in small bundles of 10–15 minutes to manage ex vivo time.

How are slit creation and implantation planned in the recipient area?

When designing recipient sites, the natural direction and angle continuity of the hair are preserved. Approximately 10–15 degrees are targeted at the frontal hairline and 30–40 degrees in the mid-scalp; at the vertex, the natural whorl axis is followed. More acute angles require shallower penetration for the same length, helping to protect the deep vascular plexus. Coronal slit orientation and the use of semi-conical blades can reduce tissue injury and the risk of “popping.” In procedures performed with the FUE Technique, slit depth is left slightly shorter than the graft length to help stabilize the graft in its bed. Implantation can be performed by placing with forceps into pre-made slits or using a DHI implanter pen. The implanter approach can be advantageous for dense packing; however, especially with sharp implanter techniques, experience and tissue compatibility determine success. Grafts are handled gently without touching the bulb, the slit width is planned about 0.1–0.2 mm narrower than the graft, and the field is kept constantly moist with a saline mist. In well-vascularized tissue conditions, 30–40 FU/cm² provides a good growth-risk balance for most people; 50–60 FU/cm² is reserved for selected beds, and perfusion and popping dynamics are carefully monitored throughout the procedure.

How do we explain “how many follicles are harvested and implanted per cm²”?

In an average patient with a donor base density of 65–75 FU/cm², harvesting 15–20 FU/cm² in a single pass is considered safe, and 40–50 FU/cm² implantation is planned for a single session to the recipient; if more than one session is anticipated, the goal is to leave at least 40–50 FU/cm² in the donor. When the hair shaft is thick and the tissue is well-vascularized, harvesting density can be increased to 25–30 FU/cm² and implantation to 50–60 FU/cm². In people with thin hair shafts or limited donor capacity, harvesting is planned at 10–15 FU/cm² and implantation at 30–35 FU/cm², distributing density more intelligently with optical illusion techniques. When it is necessary to explain things in terms of individual hairs, it is clearly stated—using an assumption of approximately 2 hairs/FU—that 35 FU/cm² ≈ 70 hairs/cm²; of course, the actual hairs/FU value is determined by measurement in every patient.

How are graft sorting-counting and quality control carried out?

The sorting-counting team regularly counts, by lot, the proportions of single, double, triple, and higher-hair FUs and records the ATE (average hairs/FU) value. Throughout the operation, the transection rate is kept below 10 percent if possible. The average ex vivo time of grafts is planned to be under 2–3 hours, and temperature-humidity records of trays and work surfaces are kept in 15–30 minute intervals. For outcome monitoring, photo and trichoscopy checks are performed at months 6–12.

Which practices reduce the risk of complications?

To control edema and bleeding, tumescent pressure is not increased beyond what is necessary; tissue ischemia times are considered with adrenaline-containing solutions, and slit creation is distributed “scatter-style” throughout the procedure to allow recovery intervals for the tissue. Skin temperature is not raised with high-intensity light sources and hot air flows; because such equipment quickly dries grafts, the use of moist gauze and regular saline application is maintained in the field. For donor aesthetics, consecutive harvesting from the same row is avoided; a mosaic-style, homogeneous distribution is preferred. In patients prone to pain and vasovagal responses, Trendelenburg positioning, warming blankets, oral fluid support, and short breaks are planned.

How are the first post-operative days managed?

In the first 24 hours, the recipient area is gently moisturized, trauma is avoided, and controlled crust cleansing is performed for 7–10 days. Cold compresses applied to the forehead are planned so as not to contact the grafts directly; 10–15 minute applications are separated by 45–60 minute intervals. Medication and washing protocols are provided according to the clinic’s standards, and in suitable patients, long-term medical therapies such as finasteride or minoxidil are considered.

Why are these numbers and ranges set this way?

All ranges—such as donor density, safe harvesting limits, recipient density targets, and holding temperature/time—have taken shape in the common ground of international experience and guidelines. A donor range of 60–100 FU/cm² is frequently seen, and it is recommended that planning be done with densitometry. Harvesting 10–15 FU/cm² in a single pass is a safe band that preserves donor aesthetics in most average donors. In the recipient area, 30–40 FU/cm² balances growth rate and natural appearance; 50–60 FU/cm² can be applied safely only when tissue conditions are appropriate. Preventing graft desiccation and keeping total times short are the strongest variables determining viability; if waiting is prolonged, cold storage at around 4 °C and, when necessary, the use of advanced solutions are reasonable choices.

How is the intra-team workflow standardized?

A brief briefing is held at the start of the operation, and the day’s target graft count, density map, role distribution, safe harvesting limit, graft holding protocol, and the person responsible for temperature tracking are clarified. During the donor phase, the transection rate is reviewed every 30 minutes, the harvesting distribution matrix is checked, and, if necessary, an interim check with photos is performed. During holding, temperature is recorded every 30–45 minutes, the solution level and tray rotation are controlled. In the recipient phase, slit creation and implantation proceed asynchronously; a “fresh slit–fresh implant” cycle is maintained, and the amount of popping in the field and bleeding control are continuously monitored. At closure, total graft and hair counts, ATE, average ex vivo time, and any complication notes are written into the report, and post-op education is reiterated to the patient.

Frequently Asked Questions

At what temperature are grafts kept? For short waits, the difference between room temperature and cold may be limited; however, if the wait is prolonged, a target of around 4 °C is a safe approach. In general, the 2–8 °C range is a practical band. The basic rule is to keep grafts continuously moist and to keep the total waiting time as short as possible.
How often should the ice pack be changed? Here, the “time rule” does not apply—the “temperature rule” does. When the internal temperature of the container rises above 8 °C, replace the ice pack or increase its amount; when it drops to 1–2 °C, reduce ice contact to prevent freezing. In typical rooms, a change every 2–3 hours is often sufficient; but the decision should be made according to the measured temperature.
With the FUE Technique, how many follicles are harvested and implanted per square centimeter? Harvesting about 15–20 FU/cm² from the donor in a single pass is safe; implanting 40–50 FU/cm² in a single session yields good results for most people. With the assumption of 2 hairs/FU, 40 FU/cm² corresponds to 80 hairs/cm². Densities are personalized according to hair thickness, vascular structure, and tissue conditions.

Step by step, how does the entire FUE Technique process proceed?

The process starts with planning and mapping, in which the person’s pattern of loss and donor capacity are determined numerically. Then local anesthesia and tumescent infiltration are applied; this provides comfort and reduces bleeding, while increasing tissue turgor to facilitate harvesting. During donor harvesting, the punch is advanced parallel to the hair exit angle, controlled with a depth guard, and the steps of scoring–dissection–extraction are followed. Manual or motorized systems can be chosen; the transection, buried graft, and speed profiles of sharp/dull punches and SAFE-like systems differ. In the graft holding phase, grafts are kept constantly moist, implanted as quickly as possible, and—if waiting is prolonged—preserved cold at approximately 4–10 °C in an appropriate solution. In recipient site preparation, the hairline, angle-direction continuity, and vessel-sparing slit design are planned; more acute angles provide shallower penetration, coronal slits and semi-conical blade choices reduce tissue-vascular injury, and the slit is left slightly shorter than the graft. Implantation is performed with forceps or an implanter pen; the method is selected in line with the target density and tissue conditions.

What does punch and instrument choice change in the outcome?

In current practice of the FUE Technique, the 0.8–1.0 mm band is the most commonly used range, and a 0.9 mm punch is a popular starting choice for the scalp. Although transection rates tend to decrease as the diameter increases, tissue scarring and vascular trauma potential may increase. Therefore, in the FUE Technique, punch selection is personalized by evaluating, together, hair shaft thickness and curl, skin elasticity, and the team’s transection performance.

FUE Technique summary

FUE Technique is a modern excision method performed with 0.7–1.0 mm micro punches. The FUE Technique allows natural hair follicles to be removed one by one without leaving a linear scar and transplanted into sparse areas. In most average donors, harvesting 15–20 FU/cm² in a single pass is considered safe from the perspective of the FUE Technique. In the recipient area, a target density of 40–50 FU/cm² with the FUE Technique is ideal for natural and lasting results; the 35–45 FU/cm² range is considered a minimally acceptable density. In selected cases—if tissue and vascular structure are suitable—the FUE Technique can reach 50–60 FU/cm², but careful planning is required in that scenario. During the FUE Technique, recipient angles are typically set between 15–60 degrees; more acute angles in the frontal area enhance naturalness, while the coronal slit approach supports vessel preservation. Protecting grafts is also extremely important in FUE Technique applications. While room temperature may suffice for short waits, if the waiting period is prolonged, it is recommended within the scope of the FUE Technique to store grafts at approximately 4 °C in suitable solutions. When performed by an experienced team in sterile room conditions with a culture of systematic record-keeping, the FUE Technique offers predictable, safe, and aesthetically satisfying results. For this reason, the FUE Technique is considered one of the most preferred and most trusted methods in hair transplantation today.