DHI (Direct Hair Transplantation)

Hair grafts from a donor area are immediately transplanted (i.e., removed and implanted) to the recipient area using a device called the Choi Implanter Pen in a modified type of FUE hair transplantation called Direct Hair Transplantation (DHI).
What is the Choi Implanter Pen?
The Choi Implanter Pen is a surgical instrument that looks like a pen and contains a tube and plunger attached to a 0.5 mm-1.5 mm hollow cylindrical needle (at the implanter's tip).

The Choi Pen was developed at Kyungpook National University in South Korea to integrate the processes of graft extraction, channel creation, and graft implantation to speed up hair transplantation.
What is the Function of the DHI/ Choi Pen?
During a DHI hair transplantation, the hair transplant specialist uses tweezers to load hair follicles retrieved from the donor location into the hollow needle of the implanter. Then, the loaded follicles are implanted into the recipient region without incisions by squeezing down the plunger at an angle of 40-45 degrees.

Slits (i.e., lateral cuts) in the recipient area are not required using the DHI method. As a result, the interval between graft extraction (when the blood supply to the hair follicles is severed) and hair follicle implementation (when the grafted tissues can begin to regenerate their blood supply to survive) is reduced.


Choi pen enables hair transplantation without shaving the recipient area, making it the greatest alternative for long hair transplants. Because it is easier to conceal the donor location with DHI, it is considered an appropriate hair transplant for women and celebrities (as you may notice from the before-after celebrities’ photographs that had a hair transplant for thinning edges or to lower hairline).
DHI procedure steps:
1. The hair transplant doctor will redraw the hairline, which could be any other areas of the scalp where hair transplantation is required (temples, forehead, whole head, etc.)
2. The patient is given local anaesthesia to numb the donor and recipient sites, or light sedation to eliminate any potential discomfort, while staying entirely conscious during the procedure. (If you're wondering if a hair transplant is painful, consider this option.)
3. Only the hair at the extraction site is shaved to a length of around 2,0 mm.
4. Grafts are extracted one at a time from the donor areas, using a micro-motor and micro-punches with sizes ranging from 0.6–0.7–0.8 mm.
5. These grafts are inserted with care during a DHI hair transplant.
Ask the Doctor
Feel free to contact us if you would like to learn more about hair transplantation in our clinic and how it can help you. Our assistants will contact you as soon as possible to prepare your treatment, explain the next steps, and what you can expect.