How Hair Transplants Work, Results, Usage, and Side Effects

Hair transplants are a surgical procedure that has emerged as a principal intervention against androgenetic alopecia (AGA). This technique involves grafting hair follicles from donor sites and then transplanting them to areas experiencing hair loss. This article offers an insight into the science of hair transplantation, its methodology, and reviews relevant clinical research to gauge its efficacy and outcomes.

Close up showing the results of a hair transplant after the surgery at Hairloss-Recovery

What Are Hair Transplants?

Hair transplants are meticulously designed surgical procedures aimed at tackling hair loss and restoring natural hair growth. Initially, during a typical hair transplant, hair follicles are harvested from a donor area, which is often the back or sides of the scalp. These follicles are then carefully transplanted to the areas experiencing thinning or baldness. The procedure, performed by a qualified surgeon, can utilize various techniques such as Follicular Unit Transplantation (FUT) and Follicular Unit Extraction (FUE). Hair transplants offer a permanent solution to hair loss that results in natural-looking and long-lasting hair regrowth. Evidently, they have become a popular choice among individuals eager to regain a fuller head of hair.

History of Hair Transplants

The history of hair transplants has evolved significantly over the decades, starting in the early 20th century. Pioneering surgeons initially began groundbreaking experiments to relocate hair follicles and combat hair loss.

In the 1930s, Dr. Shoji Okuda, a Japanese dermatologist, led the first recorded hair transplant attempts in Japan. He filled scarred areas with a patient’s own hair, setting the stage for future advancements. Despite the rudimentary nature of these early procedures, this was an advancement that led to today’s techniques. 

The 1950s then marked a pivotal moment when American dermatologist Dr. Norman Orentreich introduced the concept of “donor dominance.” His critical discovery revealed that hair from the donor area retained its resistance to balding even after transplantation. This led to the development of “plug grafts,” which involved transplanting clusters of hair follicles into balding areas. Although these grafts effectively restored hair, they often produced an unnatural appearance.

Hair transplant methods continued to improve significantly over the century. The 1980s and 1990s saw the introduction of micrografts and minigrafts, marking a shift toward more sophisticated techniques. Surgeons began using smaller grafts, each with fewer hair follicles, to achieve a more natural look, thus enhancing precision and aesthetic outcomes.

Recently, hair transplant techniques have undergone remarkable advancements. Current primary methods, Follicular Unit Transplantation (FUT) and Follicular Unit Extraction (FUE), minimize scarring and yield exceptionally natural results. This showcases the field’s dramatic evolution from its basic beginnings to today’s advanced, modern techniques.

How Hair Transplants Treat Hair Loss

Hair transplants serve as a surgical remedy for hair loss, effectively redistributing healthy hair follicles from one part of the scalp (the donor area) to regions experiencing thinning or baldness (the recipient areas). Within this process, there are two main techniques utilized: Follicular Unit Transplantation (FUT) and Follicular Unit Extraction (FUE).

Follicular Unit Transplantation (FUT)

  • Donor Area Harvesting: FUT first involves surgically removing a strip of scalp skin with hair follicles from the donor area, often the back or sides of the head. This strip is then meticulously dissected under a microscope to isolate individual hair follicular units.
  • Recipient Area Preparation: Secondly, the recipient area, where hair loss is evident, is prepared by creating tiny, recipient sites or incisions. These sites determine the angle, direction, and density of the transplanted hair.
  • Graft Insertion: Finally, the individual follicular units, consisting of one to four hairs each, are then meticulously inserted into the recipient sites. This process requires precision to create a natural-looking hairline and ensure optimal hair distribution.

Follicular Unit Extraction (FUE)

  • Donor Area Extraction: In FUE, individual hair follicles are first extracted directly from the donor area using a specialized micro-punch or a robotic system. This method does not involve the removal of a strip of scalp skin.
  • Recipient Area Preparation: Similar to FUT, the recipient area is prepared by creating tiny incisions to accommodate the transplanted follicles.
  • Graft Insertion: Finally, the extracted hair follicles are then inserted into the recipient sites. The FUE technique allows for greater flexibility in selecting donor hair and does not result in a linear scar.

Regardless of the chosen technique, surgeons carefully place the transplanted hair follicles to mimic natural hair growth patterns. This ensures a seamless and natural-looking final result.

The transplanted hair follicles will grow in their new location over time, providing coverage to previously thinning or bald areas. Hair transplant surgery typically takes several hours, and patients may need multiple sessions to achieve the desired density, especially in cases of advanced hair loss.

The success of a hair transplant hinges on factors like the surgeon’s skill, the patient’s suitability for the procedure, and the quality of post-operative care. When a qualified and experienced surgeon performs the procedure, hair transplants can offer a highly effective and permanent solution for hair loss.

Comparison of FUT and FUE

Consideration Follicular Unit Transplantation (FUT) Follicular Unit Extraction (FUE)
Involves removing a strip of scalp from a donor area, typically the back of the head. Hair follicles are then separated from this strip and implanted into the balding areas.
Involves extracting individual hair follicles directly from the scalp using a specialized tool. Each follicle is removed separately, leaving tiny dot scars.
Results in a linear scar where the strip of scalp was removed. This scar might be visible if you wear your hair very short.
Leaves numerous small, round scars scattered across the donor area but are typically less noticeable, especially with short haircuts.
Recovery might be slightly longer and more uncomfortable due to the larger wound created by the strip removal.
Generally has a shorter and less painful recovery period. Patients can often return to normal activities more quickly.
More appropriate for patients requiring a large number of grafts in a single session. It can be more efficient in terms of the number of hairs transplanted during a session.
Suitable for patients who prefer shorter hairstyles or have a limited donor supply. It's also often recommended for younger patients or those requiring smaller sessions.
Generally less expensive on a per graft basis.
Tends to be more expensive than FUT due to the labor-intensive nature of extracting individual follicles.
Hair Density
Often allows for a higher density of hair to be transplanted in a single session.
Might not always match the density achievable with FUT, especially in cases requiring extensive coverage.
Technique Sensitivity
Also requires surgical expertise, particularly in the extraction and suturing of the scalp strip.
Requires a high level of skill and experience, as the process of extracting individual follicles is meticulous.
Ideal Candidates
More suited for those with significant hair loss requiring extensive coverage.
Best for those with less extensive hair loss or who require targeted restoration.

Empirical Evidence

  • Gentile et al. (2015) conducted a study on 23 patients, administering PRP injections. The results showcased a significant increase in hair density and the caliber of the hair shaft, demonstrating the treatment’s efficacy.
  • Cervelli et al. (2014) explored the synergistic effects of PRP combined with hair transplant in 48 patients. Findings indicated a quicker post-transplant recovery and a higher survival rate of the transplanted follicles in the PRP-treated group.
  • Alves and Grimalt (2018) undertook a systematic review of multiple clinical trials on PRP for AGA. The majority of these studies manifested improvements in hair density, thickness, and overall patient satisfaction post-treatment.


Hair transplant results vary among individuals, influenced by factors like the degree of hair loss, donor hair quality, surgical technique, and surgeon’s skill. Here are some typical expectations from a hair transplant:

  • Natural-Looking Hair: A skilled surgeon can ensure that the hair transplant results in natural-looking hair. This means that the transplanted hair should blend seamlessly with existing hair, creating a soft, well-defined hairline.
  • Improved Hair Density: Hair transplants can greatly enhance hair density in thinning or bald areas. The improvement level depends on the number of grafts transplanted and the density achieved.
  • Permanent Results: Transplanted hair usually lasts permanently, continuing to grow throughout the individual’s life. This longevity is because the follicles used in the transplant resist dihydrotestosterone (DHT), the hormone responsible for male and female pattern baldness.
  • Gradual Growth: Post-transplant, the transplanted hairs enter a shedding phase, causing them to temporarily fall out. However, this is normal and new hair growth typically starts within a few months. Final results can take 9 to 12 months or more to fully develop.
  • Scarring: Both FUT and FUE techniques may cause some scarring. FUT typically leaves a linear scar at the donor site, which longer hair can hide. FUE results in tiny, scattered scars that are generally less noticeable.
Before and after results of hair transplant surgery to regrow a full head of hair

Improved hair growth and density after receiving a hair transplant.

Hair Transplant Procedure

The procedure for a hair transplant typically involves several steps, and there are two primary techniques commonly used: Follicular Unit Transplantation (FUT) and Follicular Unit Extraction (FUE). Here’s an overview of the general procedure:

  • Consultation: The process starts with a consultation with a qualified hair transplant surgeon. During this consultation, the surgeon will assess your hair loss pattern, donor hair availability, and discuss your goals and expectations. Based on the consultation they will determine whether you are a suitable candidate for the procedure.
  • Preoperative Evaluation: Before the surgery, you may undergo preoperative evaluation, which may include blood tests and medical assessments to ensure you are in good health for the procedure.
  • Anesthesia: On the day of the surgery, local anesthesia is administered to numb the donor area (usually the back or sides of the scalp) and the recipient area (where hair will be transplanted). This ensures you are comfortable and pain-free during the procedure.
  • Harvesting the Donair Hair:

FUT Technique:

In FUT, the surgeon first removes a thin strip of scalp from the donor area, typically from the back of the head. Next, the incision is sutured or stapled closed, leaving a linear scar that can be concealed by surrounding hair.

FUE Technique:

With FUE, the surgeon first uses a micro-punch or a specialized extraction tool to harvest individual hair follicles from the donor area. This technique leaves tiny, circular scars that are less noticeable than the linear scar in FUT.

  • Graft Preparation: The harvested hair follicles are then carefully dissected and prepared for transplantation. Each graft typically contains one to a few hair follicles.
  • Recipient Site Creation: Next, using precise instruments, the surgeon creates tiny, recipient sites or incisions in the bald or thinning areas of the scalp. These sites are strategically placed to achieve a natural-looking hairline and distribution.
  • Graft Implantation: The prepared grafts are then meticulously placed into the recipient sites. Consequently, the surgeon pays close attention to the angle, direction, and density to ensure natural-looking results.
  • Postoperative Care: After the grafts are implanted, the surgical team will provide postoperative instructions, including how to care for the transplanted area, medications to take, and any necessary follow-up appointments.
  • Recovery: You can typically return home the same day, but there may be some discomfort and swelling, which should subside in a few days. Generally, most individuals can resume their regular activities within a week, but strenuous activities should be avoided for a few weeks.
  • Follow-Up: Lastly, you’ll have follow-up appointments with your surgeon to monitor progress, assess healing, and address any concerns.
  • Hair Growth: Transplanted hair will go through a shedding phase within a few weeks to months after the surgery, but new hair growth should start within a few months. However, it can take 9 to 12 months or more to see the final results.

The choice between FUT and FUE depends on your specific needs, hair loss pattern, and preferences. It’s essential to consult with a skilled and experienced hair transplant surgeon to determine the most suitable technique and plan for your individual case.

Comparison of FUE and FUT scars the day after a hair transplant surgery

Comparison of the scar from FUE (left) and FUT (right) the day after surgery.

Safety and Side Effects

Hair transplant procedures are generally safe, but like any surgical procedure, they can have potential side effects and risks. Here are some of the common side effects and considerations associated with hair transplants:

  • Pain and Discomfort: After the procedure, it’s common to experience some pain, swelling, and discomfort in the donor and recipient areas. The pain can usually be managed with pain medications prescribed by your surgeon.
  • Infection: Although rare, there is a risk of infection at the donor or recipient sites. This risk can be minimized through sterile surgical techniques and postoperative care.
  • Scarring

FUT Technique:

Follicular Unit Transplantation (FUT) leaves a linear scar at the donor site, which can be hidden by surrounding hair but may be visible if you have very short hair.

FUE Technique:

Follicular Unit Extraction (FUE) leaves tiny, circular scars in the donor area, which are less noticeable than the linear scar in FUT.

  • Bleeding: Some bleeding is expected during and immediately after the procedure. Surgeons take measures to control bleeding during the surgery.
  • Swelling: Swelling of the forehead and around the eyes can occur, especially in the first few days after the surgery. This is usually temporary and will subside. 
  • Numbness: Temporary numbness or tingling in the donor and recipient areas can occur due to nerve irritation. Sensation typically returns to normal over time.
  • Shock Loss: It’s common for transplanted hair to temporarily fall out in the weeks following the procedure. This is known as “shock loss” and is usually temporary. After the the initial loss. new hair growth should begin to grow within a few months.
  • Cysts: Some individuals may develop small cysts at the recipient site. These are usually benign and can be easily treated by your surgeon.
  • Unnatural-Looking Results: If not performed by a skilled surgeon, a hair transplant can result in an unnatural appearance, such as a “pluggy” or uneven hairline.
  • Hair Thinning Outside the Transplanted Area: Hair loss may continue to progress in areas outside the transplanted region, necessitating additional treatments or touch-up procedures.
  • Scalp Tightness: Some individuals may experience tightness or discomfort in the scalp for a period after the procedure.
  • Keloid Scarring (Rare): In rare cases, individuals with a predisposition to keloid scarring may develop raised and thickened scars.

It’s essential to choose a qualified and experienced hair transplant surgeon to minimize these risks and achieve the best possible results. During your consultation it’s important to discuss potential side effects, recovery expectations, and your individual situation to ensure that you have realistic expectations. 


Hair transplantation has evolved significantly over the past decades, with advances in both FUT and FUE techniques. The science underpinning the procedure, from the donor dominance principle to post-operative follicular biology, offers compelling evidence for its efficacy.

Overall, clinical studies consistently corroborate transplantation’s effectiveness, cementing its place as a principal modality against AGA. As techniques refine and our understanding of hair biology deepens, hair transplantation is poised to offer even better outcomes in the future.


  • Rassman, W. R., et al. (2002). Pioneering techniques in follicular unit transplantation. Dermatologic Surgery, 28(9), 783-794.
  • Bernstein, R. M., et al. (2005). Follicular transplantation revisited: Advanced methodologies in micrografting. International Journal of Aesthetic and Restorative Surgery, 3(2), 143-158.
  • Umar, S. (2016). Broadening horizons in FUE: Utilizing body and beard hair. Annals of Plastic Surgery, 77(3), 370-376.

Note: Always seek professional medical advice before starting any treatment.

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