- Hotline: 852+ 2891 9689
- Whatsapp: 852+ 9146 8426
- [email protected]
- 6/F 29 Austin Road, Tsimshatsui, Kowloon, Hong Kong
Understanding Hair Science is Essential in Treating Hair Loss
Last Updated: 6 Nov 2025
Different hair loss types ( e.g., androgenetic alopecia, scarring alopecia, telogen effluvium ) affect different parts of this structure.
Understanding the hair anatomy is essential when receiving treatment for hair loss. It ensures that therapies are accurately targeted, respect the natural roles of hair, and support healthy regrowth without causing unintended damage. Without this knowledge, treatments may be ineffective or even harmful, leading to poor outcomes.
The bulge in the middle of the hair follicle contains stem cells. It is the most important part in follicle growth and regeneration. During hair transplant this segment of the graft must be well preserved. In FUE, when too small a punch is used, the extracted follicle may deprived of bulge tissue. In “Hair Cloning”, the dermal sheath of the follicle is cultured in medium.
The multiplied tissue is then injected into the skin to induce new hair formation. The stem cells in the bulge is multi-purposes. Hair follicle transplant had shown to return skin color in a skin disease called “vitiligo”. The average healthy hair fiber diameter is 0.08mm or over. Below 0.04mm the hair fibers are too thin to achieve visual coverage of the scalp
Many treatments are being developed to stimulate the stem cells: new hair follicles can be formed; even white hairs can turn black. 5 α reductase converts testosterone into DHT. This enzyme is located in the Sebaceous Glands.
Dr Inaba ( Japan ) believes that over consumption of animal fat swells the sebaceous gland, increases the amount 5 α reductase and DHT, leading to earlier onset of androgenetic hair loss.
Laser is able to stimulate and preserve hair follicles in patients with androgenetic alopecia and other hair loss disorders. Laser has been used over the past few years in a number of laser devices ( combs, caps, hairdryer-like ) for treatment of genetic or acquired hair loss. The Laser energy addresses hair loss at the hair follicle cellular level, rejuvenating miniaturizing hair follicles in seven major ways:
The soft silky hair that covers the fetus in utero, usually shed before birth.
Non-pigmented fine hair with diameter less than 0.03mm. These covers the whole skin surface except the palms and soles, and includes early miniaturized depigmented terminal hair found in Androgenetic Alopecia. Usually do not grow beyond 1cm in length.
Longer, coarser, and pigmented hair with diameter above 0.06mm. Can grow beyond 1cm in length. Before puberty these are restricted to the scalp, eyebrows and eyelashes. After puberty secondary terminal hair develops from vellus hair in response to androgen in axillae, pubic area, and front of the chest in men ( Androgen Dependent Hair – see below ).
Diameter 0.03mm to 0.06mm, consists of early miniaturization of terminal hair in Androgenetic Alopecia.
Androgens (male hormone) regulate changes in human hair growth. In puberty the increase production of androgen changes the childhood vellus follicles into pigmented terminal follicles in many areas, including pubic and axillary hair, beard and moustache. These are called Androgen dependent hairs.
Unfortunately androgens have the opposite effect on scalp hairs. They reverse large, terminal, scalp follicles back to small vellus pale hairs and cause balding. Scalp hairs are therefore not androgen dependent.
There are 3 Distinct Structures in Scalp Hair Follicles :
Component | Content % | Remarks |
|---|---|---|
| Keratin | 80%-90% | • Formed from dead protein • Contains 20 kinds of amino acids• Provide strength for the shaft |
| Water | 10%-30% | Provide shaft elasticity |
| Lipid ( Fat ) | 10% | |
| Trace Elements | Very small Quantity | Zinc, Mercury, Cobalt, Iron, Selenium … |
| Melanin | — | Accounts for hair color |
Hair root, also known as Dermal Papilla, is a tunnel-like segment of the epidermis that extends down into the dermis. It can be divided into 2 compartments :
Protect and form the growing hair shaft. Also service as source of energy for protein synthesis during hair growth. Cells found in ORS are :
Consists of 3 layers :
The tissue surrounding the hair root is known as Adventitous Tissue. It is consisted of several components:
A muscle attaches the bulge to the skin. When this muscle contracts, it causes the hair to stand up which also causes the sebaceous gland to secrete oil. This muscle must be cut in FUE to extract the follicle.
Contain melanosomes and synthesize melanins which account for the pigmentation of hair and skin.
Opens into the isthmus. This gland secretes sebum, a semi-fluid secretion consisting chiefly of fat, keratin, and cellular material. The sebum lubricates shaft and carries away debris generated in the follicle.
Scientists have discovered that stem cells are plentiful in the fat tissue, the so called Adiposed Stem Cells (ASC). ASC has been used in cardiovascular and cosmetic surgery to generate new tissues.
A study by Beehner (2010) compared the survival of chubby grafts and skinny grafts. The differences in survival is proportional to the amount of retained surrounding tissues. Stem cells are retained in chubby grafts but trimmed away in the skinny grafts.
% growth after 19 months | Skinny Graft | Chubby Graft |
|---|---|---|
| 2-hair follicular units | 69.3 % | 88.0 % |
| 1-hair follicular Units | 48 % | 98 % |
For years, one of the most persistent criticisms of Follicular Unit Extraction ( FUE ) centered on graft survival — specifically, the concern that “ skinny grafts ” harvested with small-diameter punches ( typically 0.6–1.0 mm ) lacked sufficient surrounding tissue to support long-term viability. This critique was often contrasted with Follicular Unit Transplantation ( FUT ), where grafts are excised as part of a strip and retain a thicker layer of perifollicular fat and connective tissue — dubbed “chubby grafts.”
A pivotal 2010 study by Dr. Maryanne Beehner highlighted this difference: chubby grafts demonstrated higher survival rates, largely because they preserved critical components like adipose tissue, vascular networks, and—most importantly—stem cells residing in the dermal sheath and bulge region. In traditional FUE, aggressive trimming to fit narrow recipient sites often stripped away these supportive tissues, inadvertently removing regenerative cells essential for graft take and long-term hair cycling.
As a result, skeptics argued that FUE’s minimalistic approach compromised biology for aesthetics—offering less scarring but at the cost of lower yield.
But the narrative has changed — dramatically.
Advances in biotechnology and regenerative science have transformed FUE from a technique once questioned for its biological limitations into the gold standard for modern hair restoration. Key innovations include:
ATP-enriched preservation solutions : Adenosine triphosphate ( ATP ) fuels cellular metabolism during the critical ischemic period between extraction and implantation. By bathing grafts in ATP-boosted media, clinics now dramatically improve follicle resilience and revascularization.
Low-level laser therapy ( LLLT ) : Pre- and post-operative LLLT enhances mitochondrial function in grafts, reduces inflammation, and accelerates healing in both donor and recipient zones.
Minimally trimmed, tissue-sparing FUE protocols: Modern FUE no longer demands ultra-skinny grafts. With refined punch designs and magnification-assisted dissection, surgeons can harvest grafts that retain just enough perifollicular tissue — preserving stem cells while still fitting naturally into eyebrow or scalp sites.
Platelet-rich plasma ( PRP ) and growth factor cocktails : Used during implantation, these biologics create a pro-regenerative microenvironment that mimics the natural niche of the hair follicle.
Thanks to these tools, graft survival rates with FUE now rival — and in some studies, exceed — those of FUT, while offering the undeniable advantages of no linear scar, faster recovery, and greater patient comfort.
Interestingly, the very fat layer that once gave FUT grafts their survival edge may also pose a limitation. That thick adipose cuff can impede the diffusion of oxygen and nutrients from surrounding tissue in the early post-op phase—especially in densely packed recipient sites like eyebrows or hairlines. Without rapid vascular integration, even well-nourished grafts risk necrosis.
In contrast, today’s optimized FUE grafts strike a balance : enough supportive tissue to protect stem cells, but lean enough to allow immediate nutrient exchange upon placement.
The evolution of FUE is a testament to how technology can elevate technique. What was once criticized as “too skinny” is now celebrated as precision-engineered biology — thanks to biotech innovations that honor the living nature of the hair follicle.
Today, FUE isn’t just about avoiding scars — it’s about maximizing regenerative potential. And in the era of ATP, lasers, and stem cell-aware harvesting, it has rightfully earned its place as the preferred method for natural, high-yield, permanent hair restoration.
conditions of use
Information provided on this website is for educational purposes only and is not intended as medical advice. It should not be interpreted as promotional material or as claims of superiority over other techniques or providers.
Individual results may vary, and no outcome can be guaranteed. Always consult with a qualified healthcare professional before making any decisions about medical treatment.
Paragraph
Pre-Consultation Review
If you want to get a personalized answer from our medical team, you can reach us using this form here. We will cantact you as soon as possible.
Our practice adheres to guidelines established by leading international organizations in Hair Restoration.
International Society of Hair Restoration Surgery is the leading global medical association that establishes international practice standards and patient safety protocols.
The American Board of Hair restoration Surgery represents the highest standard. To maintain rigorous certification requirements the physician must demonstrate surgical expertise.
Worls FUE InstituteI serves as the premier educational body focused exclusively on Follicular Unit Extraction methodology. The institute ensures consistent application of safe FUE.
