MODI HAIR MEDICAL GUIDE
8 Things You Should Know Before a Hair Transplant
Have you wondered why transplanted hair tends to last relatively long, how incision and non-incision methods differ, or whether it is normal for transplanted hairs to fall out during the shedding phase after surgery? We explain step by step, from the principles of hair transplantation to candidate criteria, surgical methods, the recovery process, and the factors that affect graft survival.
Key Summary
- A hair transplant is a procedure that moves hair follicles from the occipital and temporal areas, which are relatively less affected by hair loss, to the areas where they are needed.
- Incision and non-incision refer to differences in the harvesting method, while implanter and slit refer to differences in the implantation method; no single approach is superior for everyone.
- Transplanted hairs may temporarily shed after surgery, and the overall result is assessed over several months.
- Results depend not only on the number of hairs transplanted, but also on long-term design, donor area allocation, follicle harvesting, storage and implantation, and post-operative care.
Watch the Video First
Dr. Yoo Hwa-jung, Representative Director of Modi Hair Plant Clinic, explains everything from the basic principles of hair transplantation to incision vs. non-incision, implanter vs. slit, the shedding phase, and graft survival management.
1. What is the principle behind hair transplant surgery?
A hair transplant is a procedure in which hair follicles are harvested from areas such as the occipital or temporal scalp, which are relatively less affected by male pattern hair loss, and moved to areas where hair is needed, such as the hairline, the M-shaped recessions, or the crown.
In male pattern hair loss, follicles that are genetically sensitive to androgens can gradually become thinner under the influence of DHT. In contrast, follicles in the safe donor area are relatively less affected by this and tend to retain much of their original characteristics even after being moved to another location. This is explained by the concept of donor dominance, which forms the basis of hair transplantation.1
Why are follicular units, rather than individual hairs, transplanted?
Hairs on the scalp do not always grow one strand at a time; one or more hairs may grow together from a single follicular unit. In modern hair transplantation, these natural follicular units are harvested and implanted with as little damage as possible. A natural appearance requires consideration of thickness, direction, and angle — for example, placing fine single-hair units along the hairline and using follicles containing multiple hairs further back.2
Apart from the transplanted follicles, hair loss can continue in existing hair that was not transplanted. Depending on the diagnosis, care for existing hair, such as medication, may also be necessary.
2. Am I a candidate for a hair transplant?
Being a candidate for surgery is not determined simply by an area looking sparse. If enough follicles remain alive, even if thinned, non-surgical treatments such as medication may be considered first. On the other hand, a hair transplant may be considered for areas where follicles are congenitally lacking or where hair loss has progressed for a long time and few recoverable follicles remain.
What to check in the recipient area
- Whether follicles still remain
- Type and rate of progression of hair loss
- Area to be transplanted and required density
- Presence of scalp conditions or scarring
What to check in the donor area
- Extent of the safe donor area
- Follicle density and hair thickness
- Harvesting marks from previous surgery
- Reserve of follicles for future use
Why is donor hair a limited resource?
A hair transplant does not create new follicles; it relocates existing ones. Because the same follicles do not regenerate at the harvest site, donor hair must be allocated with consideration not only for the current procedure but also for future progression of hair loss and the possibility of additional surgery.
There are situations in which the non-incision method may be advantageous for planning repeat procedures, but this does not mean the number of surgeries is unlimited. With both incision and non-incision methods, the total amount of donor hair that can be safely harvested is limited.2, 3
3. Why a design must consider the future, not just the present
At a younger age, one may want a low, straight hairline, but the face and hair change over time. If hair loss in existing hair progresses backward while only the front hairline remains excessively low, the result can look unnatural, or donor hair for additional surgery may become insufficient.
Therefore, in addition to hairline height, connection at the temporal area, and hair direction and angle, age, family history, the current stage of hair loss, and the expected extent of progression must all be considered together. A good design is less about filling in today's empty space and more about a plan for using a limited supply of donor hair in a balanced way over the long term.
4. What is the difference between incision and non-incision hair transplants?
A hair transplant is broadly divided into the harvesting stage, in which follicles are obtained from the occipital area, and the implantation stage, in which they are moved to the required locations. Incision and non-incision are terms that distinguish the method of harvesting follicles.
| Comparison item | Incision method (FUT) | Non-incision method (FUE) |
|---|---|---|
| Harvesting method | A strip of occipital scalp is harvested and then separated into follicular units | Follicular units are harvested one by one with a small punch |
| Type of scarring | A linear scar may remain at the suture site | Small dot-shaped marks may remain, scattered across the area |
| Operating time | Depending on conditions, a large number of follicles can be obtained relatively efficiently | Time may be longer depending on the number of hairs required and the difficulty of harvesting |
| Points to consider | Scalp elasticity, linear scarring, and healing of the suture site | Extent of shaving, harvest distribution, follicle transection, and the risk of over-harvesting the donor area |
"Non-incision" means there is no incision line; it does not mean there is no scarring or pain at all. Conversely, the incision method can also be a reasonable choice depending on the patient's donor area condition and the number of hairs required. Rather than concluding that one method is superior for all patients, the decision should be made by considering the donor area condition, the desired hairstyle, the number of hairs required, and previous surgical history together.2, 3
5. What is the difference between the implanter and slit methods?
After follicles are harvested, they are implanted according to the planned position and direction. In the implanter method, follicles are loaded into a dedicated instrument and inserted; in the slit method, small channels are first created in the scalp and the follicles are then placed using forceps or similar instruments.
Implanter method
Follicles are inserted into the scalp using a loaded instrument. Skill in handling the follicles while keeping depth, direction, and angle consistent is important.
Slit method
Small channels for the follicles are created first, and then implantation is performed. The process of planning channel size, spacing, direction, and depth is important.
Evidence directly comparing the two methods is still limited, and although a recent comparative study found differences in some measures such as implantation speed and density, no significant difference was observed in final survival rate. Therefore, rather than judging the outcome by the name of the instrument alone, it is appropriate to look at how consistently and meticulously the medical team performs the method it has chosen.4, 5
6. Why does transplanted hair fall out during the shedding phase?
The period after surgery when the shafts of the transplanted hairs temporarily fall out is commonly called the shedding phase. Visible hair falling out does not immediately mean that the follicles beneath the skin have also been lost. After the transplanted hairs go through a resting phase, new hair can grow from the follicles.
The periods above are general ranges provided to aid understanding. Figures mentioned in the video, such as 60% at 6 months, 90% at 9 months, and 100% at 12 months, are not guaranteed values that apply identically to every patient. They vary according to hair growth rate, the transplanted location, individual health status, and the extent of surgery, and in some cases thickness and shape may continue to change even after one year. Clinical practice guidelines state that generally 9 months or more is needed to evaluate sufficient growth.2, 6
7. What factors affect the graft survival rate?
In hair transplantation, just as important as the number of hairs transplanted is the process of managing harvested follicles without damage and implanting them in appropriate positions. From the moment they are harvested, follicles are temporarily separated from the blood supply, so physical damage and drying, time spent outside the body, storage temperature, and storage solution must all be carefully managed. In an actual clinical trial, differences were observed in the pattern of shedding after implantation and in the timing of early growth depending on the storage solution, but in some results there was no difference in final survival rate between the two groups.7
Factors in the surgical process
- Follicle damage during harvesting
- Drying and time outside the body
- Storage solution and temperature
- Implantation depth, direction, and density
Patient and scalp factors
- Condition of the donor and recipient areas
- Smoking and underlying conditions
- Inflammation or scalp disorders
- Adherence to post-operative care
Is it always better to implant hair as densely as possible?
Appropriate density is needed for a natural sense of fullness, but placing more follicles into a small area is not always better. In a small study comparing the density of single-hair follicles in four Korean patients, the 20 and 30 units/㎠ groups showed a higher survival rate than the 40 and 50 units/㎠ groups. However, because the study involved four participants and evaluated only single-hair follicles, it should not be interpreted as a universal standard such as "30 is safe and 50 fails."8
The actual target density should be determined by considering hair thickness, the number of hairs per follicle, scalp blood flow and scarring, the transplant area, and the surgical team's technique together.
8. What role do adjunctive treatments play after surgery?
At Modi Hair Plant Clinic, accurate design, harvesting, follicle storage, and implantation form the foundation, and adjunctive treatments to support the post-operative recovery environment are considered according to the patient's condition and indications. Adjunctive treatments are not a substitute for the surgery itself, nor do they guarantee a good result.
Hyperbaric oxygen therapy
A treatment that supplies oxygen at high pressure to support the oxygen environment of tissues. In a study of 34 patients, post-operative shedding and some discomfort symptoms decreased, but the difference in survival rate at 9 months was not statistically significant.9
Treatment considering the blood flow environment
If necessary, the medical team may consider treatment addressing the microcirculatory environment after checking the patient's health status and current medications. Whether medication is used and which type requires individual consultation.
PDRN
PDRN is a substance for which research on wound healing, blood vessel formation, and inflammation control has accumulated. However, large-scale comparative trials directly demonstrating an effect on graft survival in human hair transplantation are not sufficient, so it should be understood as an adjunctive aid for recovery.10
Hair follicle–derived cell therapy
There are studies evaluating autologous hair follicle–derived cell therapy in androgenetic alopecia, but methods vary and long-term evidence is limited. The same effects cannot be assumed for use as an adjunctive treatment immediately after a hair transplant.11
More important than whether adjunctive treatments are used are diagnosis and long-term planning, safe donor area harvesting, follicle storage and accurate implantation, infection prevention, and post-operative follow-up.
Checklist before a hair transplant consultation
- What is my current type and stage of hair loss?
- Should medication be considered first or alongside surgery?
- Are the density and harvestable extent of the safe donor area sufficient?
- Are the proposed hairline and transplant volume appropriate in the long term?
- What is the reason for recommending the incision or non-incision method?
- In what environment are the harvested follicles managed and stored?
- What is the expected recovery process and what side effects are possible?
- What is the plan if hair loss in existing hair progresses?
Frequently asked questions about hair transplants
Does transplanted hair never fall out for life?
Follicles moved from the safe donor area tend to retain much of their original characteristics. However, hair thickness and density can change with aging, health status, and the environment of the surgical site, so it cannot be stated that hair will "never fall out."
Does a hair transplant also stop existing hair loss?
No. Male or female pattern hair loss can continue to progress in surrounding hair that was not transplanted. Depending on the diagnosis, medication and other care for existing hair may also be considered.
Which is better, incision or non-incision?
No single method can be said to be better for everyone. The decision is made by considering the number of hairs required, donor area density and elasticity, previous surgical history, and preferences regarding scarring and hairstyle.
If transplanted hair falls out after surgery, does that mean failure?
Not necessarily. A shedding phase, in which the shafts of transplanted hairs temporarily fall out, can occur after surgery, and new hair may subsequently grow from the follicles beneath the skin.
When can hair transplant results be seen?
Generally, new hair begins to be observed from about 3 months, and changes may gradually become more noticeable between 6 and 9 months. Overall evaluation is commonly made around 12 months, though this varies by individual and by the area treated.
Does transplanting more hair improve the survival rate and result?
Not necessarily. Donor hair is limited, and excessively dense packing can place a burden on the tissue of the recipient area. The appropriate transplant volume and density should be determined by considering hair characteristics, scalp condition, the area needed, and the long-term plan.
Before choosing a surgical method, identify the long-term plan that suits you
Only by reviewing your current hair loss status, donor area conditions, and the possibility of future progression together can an appropriate hairline and transplant volume be planned.
Through a consultation, start by carefully determining whether surgery is needed at this time.
This article is general health information prepared based on video explanations by Dr. Yoo Hwa-jung, Representative Director of Modi Hair Plant Clinic, and on medical literature. It does not replace individual diagnosis or treatment, and the surgical method, transplant volume, pain, recovery period, graft survival, and final result may vary depending on the patient's type of hair loss and the condition of the donor area, scalp, and general health. Whether adjunctive treatments are applied must also be decided after examination by a medical professional.
References
- Orentreich N. Autografts in alopecias and other selected dermatological conditions. Ann N Y Acad Sci. 1959;83:463-479. PMID 14429008 · DOI
- Mysore V, et al. Hair Transplant Practice Guidelines. J Cutan Aesthet Surg. 2021;14(3):265-284. PMID 34908769 · DOI
- Dua A, Dua K. Follicular unit extraction hair transplant. J Cutan Aesthet Surg. 2010;3(2):76-81. PubMed · DOI
- Whitworth JM, et al. A comparison of graft implantation techniques for hair transplantation. Semin Cutan Med Surg. 1999;18(2):177-183. PMID 10385286 · DOI
- Zhao Y, et al. Premade Incisions vs. Stick and Place: A Multicenter Retrospective Comparison of Hair Transplantation Outcomes in China. Aesthetic Plast Surg. 2025;49(13):3597-3604. PMID 40316792 · DOI
- Patwardhan N, Mysore V; IADVL Dermatosurgery Task Force. Hair transplantation: standard guidelines of care. Indian J Dermatol Venereol Leprol. 2008;74 Suppl:S46-S53. PMID 18688103
- Zhou Y, et al. Evaluation of a Novel Graft-Holding Solution in Hair Transplantation: A Randomized Controlled Clinical Study. Dermatol Surg. 2023;49(7):675-681. PMID 37036372 · DOI
- Lee W, et al. Survival rate according to grafted density of Korean one-hair follicular units with a hair transplant implanter: experience with four patients. Dermatol Surg. 2006;32(6):815-818. PMID 16792647 · DOI
- Fan Z, et al. The effect of hyperbaric oxygen therapy combined with hair transplantation surgery for the treatment of alopecia. J Cosmet Dermatol. 2021;20(3):917-921. PMID 32770782 · DOI
- Colangelo MT, et al. The effects of polydeoxyribonucleotide on wound healing and tissue regeneration: a systematic review of the literature. Regen Med. 2020;15(6):1801-1821. PMID 32757710 · DOI
- Gasteratos K, Kouzounis K, Goverman J. Autologous Stem Cell-derived Therapies for Androgenetic Alopecia: A Systematic Review of Randomized Control Trials on Efficacy, Safety, and Outcomes. Plast Reconstr Surg Glob Open. 2024;12(2):e5606. PMID 38352219 · DOI