dhi hair transplantation

Dhi Hair Transplant

Dhi hair transplant method (hair implant with a pen implanter) was developed by Dr. Young Choi back in the begging of 1990. This method of graft implantation has become popular worldwide, especially in Far East Asia. The technique is known under different names, such as Choi implanter pen, hair implanter pen, hair transplant pen, and no-touch hair transplant. Dr. Hakan Doganay is a leading specialist in the implanter pen method in Turkey. He has been successfully transplanting hair with this technique since 2009. 

Together with its popularity in our country, the method gained an incorrect name too. DHI is the initial letter of the clinic name in Greece ‘Direct Hair Implant’ which practices hair transplants by the pen. There is no such technique as Dhi.  We realize that the term is inappropriate, although we will refer to it further because it is commonly used by society.

From 2009 till today we have been achieving excellent results by the Dhi hair transplant method. Dhi has many advantages compared to FUE hair transplant.  Together with the popularity of the FUE harvesting, the Dhi method gained rapid demand too. However, it is worth remembering that Dhi hair transplant is not a special application of FUE. It was successfully used with FUT harvesting for a long time. Unfortunately, not all surgeons can succeed with the Dhi implanter pen because it requires detailed technical knowledge and experience. Comparatively high equipment cost also makes the method less attractive for many doctors in Turkey.

What is Dhi Hair Transplant?

Dhi implanter pen was invented by Dr. Choi. It is a spring-like tool similar to a regular pen,  also called an implanter pen. Opening all channels simultaneously with implantation is a general difference of this method. This technique, if properly implemented, can be referred to best hair transplant method. Before stage of the Dhi hair transplantation is similar to others, no extra preparations are required. To get a detailed understanding of the procedure, you can visit our hair transplant surgery in Turkey page.

Types of Pen Implanters and Technical Information About the Dhi Implanter Pen

Dhi pen is the best hair implantation method, which guarantees safe hair transplant and excellent results if operated correctly. It is essential to maintain full technical data of the procedure, otherwise, dhi results may be disappointing. Pen implanters can be divided into two major groups:

1) Sharp Needle Pen Implanter

All pens offered in Turkish market are in this group.

  1. Choi Implanter Pen. The preferred choice in Turkey
  2. KNU Implanter
  3. Lion Implanter Pen: The needle tip is relatively wider comparing to others
  4. OKT Implanter Pen
  5. HWANG Implanter: the only sharp-tipped implanter with depth control (stopper). Not used in Turkey. The needle is sharp both inside and outside. It is the most sharp-tipped implanter, moreover, its needle wall is the thinnest.

Except for Hwang, there are distributors of listed brands in Turkey. Choi Implanter Pen is a pioneer in our country. Despite the slight diversity of the mentioned pens, the main functioning principle is the same.  

implanter pen

On the picture above you can see the difference between regular pen and Huwang’s sharp tipped pen with stopper.

2) Dull Needle Implanter (DNI)

This model is not used in Turkey yet. The pen has a dull and wide-tipped needle. In the DNI case, the channel is pierced, then grafts are implanted by another pen. K.E.E.P, a pen developed by Dr. Koray Erdogan can be added into this group. The difference between classic Dhi pen and dull is that dull pen grafts are implanted by forceps.

Differences Between Sharp and Dull  Needle of Implanter Pen

SubjectSharp Needle ImplanterDull Needle Implanter
Graft ImplantStick and place methodImplantation into already open channels
Incision SizeNeedle and channel sizes are same
The open channel can be smaller than the needle. Example: for 0,9 mm channel 0,8 mm needle
Determined during graft implant

Determined before graft implant
Implantation PeriodFastRelatively slow
Needle Tip ChangeNeedle is changed when it gets dullNo need for needle change
Bleeding and Root PoppingLittleHeavier
Needle Slot DiameterTight. Generally 0,2 mmWider (Generally 0,35 mm)
Stopper & Depth ControlRemains only in Hwang ImplanterAbsent
Pros/ConsLong grafts should be taken out of the slit holding its top, otherwise implanted graft can be damaged. Thicker grafts can be destructed when implanted to tight channel.Damage risks are low

Chemical disinfectants, like Saydex or if possible Ethylene Oxide should be used for needle sterilization. We do not apply dry air sterilizers such as autoclaves or ovens because they damage needle structure and affect sharpness.

What is Dhi Implanter Pen and How it is Used?

Here we will describe the Dhi hair transplant method. You can find more information about grafts extraction on FUE hair transplant page.

As previously mentioned the implanter pen is a regular pen – spring-like looking tool. Its protection layer is made of Teflon that thrives sterilization resistance up to approximately 130-140 degrees. The pen consist of 5-6 interbedded systems. Needle tips are located at the very end of the tool. They look the same as syringe, however, their tip is vertical and slit. This helps to place grafts inside of the tip slits before implantation.  To operate quick and synchronous 4-6 implanter pens are needed for a surgery. There are 3 stages of Dhi hair transplantation.

a) Placement of Hair Roots Into the Pen

Hair follicles are swiftly placed one by one into the needle tip of the pen by doctor’s assistants. Touching graft roots is forbidden; the hair should be pulled out by forceps and slid carefully into a slot. Grafts should not be kept inside of dhi pen for a long time because they may get dry and die. If necessary, the isotonic spray is applied to moisten the pen.

b) Replacement of Empty and Filled Dhi Pen

To prevent any pinprick accidents full coordination between the doctor and the assistants is expected during the replacement of empty and filled pens. In other words, the doctor places an empty dhi pens with the needle pointed towards him, while the assistants locate filled pens perpendicularly. There should be a 30-40 cm distance between full and empty pens. Thus the synchronous operation is managed in Dhi hair transplant; moreover, neither doctor’s nor assistants’ fingers are injured by the needles.

There is an anther way where the surgeon uses only a hand wrist while the arm is in a stable position. The an assistant takes away an empty pen placing a filled one instead between doctor’s thumb point fingers. This makes the Dhi hair transplant surgery much faster. Besides, the doctor’s hand is less tired due to reduced movements.

C) Implantation of the Grafts Placed in the Pen by the Surgeon

Grafts should be placed in the pen needles. Then dhi pen is pointed to the hairless skin area at an appropriate angle; the skin is pierced by the needle tip. Once the pen top button is pushed, the hair is slid by a thin needle into the slit. Simultaneously, the spring system enables the needle to withdraw off the skin and come back to its start position. This is how hair implant surgery is done. It is important to have neck relaxed otherwise bleeding may increase due to vascular compression.

The doctor should operate with a pen easily. Dhi pen is placed between the thumb and index finger, the rest fingers (3rd, 4th, and 5th) assist additionally. This filled pen pierces the skin to implant the graft. The top button of the pen is pushed by the index finger (to slid and implant the root). Simultaneously the pen should be pulled out of the skin quickly when the graft is implanted. The doctor easily gets accustomed to this operation rhythm and the Dhi hair transplantation becomes an automatized procedure.

Dhi Hair Transplant and 7 Know-How

Particular tips helps to get a very good dhi results. Throughout our experience, we determined some special techniques and would like to share them with people willing to do the hair transplant surgery. We collected following 7 know-how for you:

1- Needle Tip Diameter of Dhi Pen

All needle tip brands in the market offer a diameter between 0,6 and 1,8mm. We operate with 0,6 / 0,8 and 1mm diameter tips. We don’t think that bigger needles can result in safe hair transplant and natural look. Here are the specifications of these needles:

  • 0,6 mm: is generally used for single graft eyebrow transplant
  • 0,8 mm: can be used to implant single or double follicles
  • 1 mm: is used to implant 2-3-4 hair grafts

Pen producers paint the top of the pen with a specific color (green, red, blue, pink) which represents a certain needle tip diameter. This significantly simplifies our job as it helps to identify the pen immediately. Below you can see an example of sharp-tipped hair transplantation pens used in our country. The needle tips are 0.6, 0.8 and 1 mm. Our suppliers produce a variety of needles with the diameter up to 1,8 mm but we do not find appropriate using tips bigger than 1 mm in diameter for Fue hair transplant.

implanter pen

On average, 700-1000 grafts can be implanted with a pen needle. However, this number varies because people have different skin elasticity. If the skin cambers and pop out the grafts during transplantation, needle tip must be changed. All in all, needle tip loses sharpness after every operation.

2- Width of Needle Slots

A very tight slot can cause damage to the hair graft when transplanted, while a wide slot causes the decline of the graft before implantation starts. The diameter of slots must vary between 0,2 and 0,3 mm. In the picture below you can see 1 mm diameter needles in high resolution; they are produced by 3 different companies. The 1st needle has a wider slot and the hair root section inside of the needle is wide too (called bevel). In our opinion, this model is the most preferable in terms of safe hair transplant.

hair implanter

3- Length of Dhi Pen Needle

One of the most important factors for hair implant is depth. Some dhi implanters have no depth control. Needle length should be adjusted according to patient’s hair in advance. Length must be adjusted to graft size.

The standard size of the pen needle is around 7mm. This length can be adjusted according to the graft size. If bleeding is intensive, the needle length should be reduced. When the standard length 7mm is set to 6,5 or 6 mm, bleeding stops immediately. In opposite, if the needle size is too short, the graft may not be rooted properly and be declined. Finally, if the graft implanted too deep, there is a risk that the root does not grow; or the hair shape defects.

A mathematical ratio should be determined between the needle and the graft length. Needle size is to be 25-30% longer than graft size. An example application should be as follows:

  • Graft size 6 mm – needle size is 8 mm (25% longer)
  • Graft size 5 mm – needle size is 7 mm
  • Graft size 4 mm – needle size is 6 mm (33% longer).

An experienced doctor can easily adjust length in a few tries.

4- Wire Length that Pushes Graft Into the Skin

This wire must not get over the Teflon spiral. If it comes out when the pen top is pushed or if it is easily visible, this means that the wire not only touches the graft’s top but also contacts the hair itself. As a consequence root may be defected. The wire should not come to the surface. In the meantime, it must not be placed very high as well. The wire has to remain on the Teflon protector level.

dhi hair implant

5- Needle in Skin and the Depth of Implantation

There is no depth adjustment problem with stopper (depth control) implanter. The implanter pen needle without stopper should not be completely inserted into the skin. Implanting about 1 mm in is enough, otherwise, graft root ends up to be too deep in the skin. A lot of practice is required to get appropriate skills in dhi hair transplant method. Once the hair graft is placed into the skin the pen must be pulled off immediately. As far as we know, nobody practices depth controlled implanter pen in our country. To operate synchronically the surgeon must have sufficient experience.

There are some consequences of deep grafts implantation:

  • a) Folliculitis and cyst: Small inflammations and sebaceous glands called cysts can occur at the hair roots.
  • b) Curly hair growth
  • c) Recess at the hair roots
  • d) Intensive bleeding after dhi surgery
  • e) The decrease in hair growth volume

As a result, the regulation of proper depth for the Dhi hair transplant is one of the most significant stages of the operation.

6- Needle Direction in Hair Implantation

According to our experience, the needle slot must be directed down (towards the skin) to achieve good hair transplant result. While a sharp part of the needle is inserted into the skin, the needle angle gets a slight horizontal position. The depth can be controlled better this way as well. Hair grafts also merge perfectly with fatty skin tissue and capillary vessels. Its another advantage is easy depth control in scarred and vertex areas.

7- Skin Streching

Dhi implanter cause pressure when the needle enters the skin. This pressure can cause popping out of the other hair grafts. To decrease the risk to a minimum, the doctor or assistants should stretch skin. The assistant pulls the skin in general and the doctor stretches a particular parts of the recipient area. Stretching is especially important in frontal zones. Additionally, stretching helps to decrease hair implantation angle and achieve a more horizontal direction of the hair.

Unexpected Situations that May Occur after Dhi Hair Transplant

Dhi hair transplant is not that easy as explained in theory. Sometimes, surgery goes like a knife through the butter but can result in bad hair transplant. We will give a few examples and solutions.

  • Bleeding: If bleeding is more extensive than expected, patient’s sitting position should be checked. Bleeding increases if the neck is under the pressure. Once the neck position is changed, bleeding stops. Sejant position under 45 degrees is ideal for hairline transplant and 60-70 degrees are more favorable for crown hair implantation. We also mentioned above that the needle length can cause bleeding.
  • Popping: During hair implant, earlier transplanted hair grafts located nearly should not pop out due to the pressure. It is the least desired situation in Dhi hair transplantation. When roots start popping out, the needles should be replaced immediately. The less elastic skin is, the more hair popping chances are. This problem is commonly met among elder people, those who actively sunbathed or have scars. Skin must be stretched carefully during implantation to prevent the popping. Additionally, the needle has to firstly slit the skin softly, then be injected from a certain angle. In this case, the needle is inserted deeper into the skin and the pressure is reduced.
Dhi Hair Transplant on Scar

Among people willing to undergo the Dhi hair transplant are those, who have scars from the FUT method or gone though accidents. Hair transplantation on injured area is different from regular implantation. This is because the skin is rougher and more pressure is needed to insert the needle. We find it more appropriate to make a channel for the graft by needle tip first on the scarred skin. Both, hypodermic needle or the empty pen needle can be implemented. Special attention must be paid to opening a proper channel suitable to hair grafts.

Once channels are made, grafts are implanted by the classic Dhi hair transplant method. All these methods help to prevent graft popping during the surgery.

What does Dhi hair transplantation give?
  • Increase the density of rare hair by unshaven hair transplant method.
  • By Dhi best Beard hair transplant results are achieved.
  • Dhi implanter is the ideal technique for whisker and beard hair transplantation, we give detailed information on relevant pages.
  • The best hair transplant method for women which does not require shaving.
  • It is certainly the best option for eyebrow transplantation. It is easier to determine the right angle and very thin needle-like 0,6 mm can be used. You can find some tips in our article dedicated to eyebrow transplant

What are the benefits of Dhi Method?

Dhi implanter is best method as mentioned previously. It has many advantages compared to the classic hair transplantation method.

*Less bleeding. After hair transplant look is ver clean.
*No scars and wounds on skin after hair transplant.
*Easy to adjust implantation angle. 
*If operated carefully, Dhi causes less damage to hair roots comparing to the Fue.
*Very dense and safe hair transplant.
*Dhi does not leave scars compared to classic FUE because it does not require skin cuts. All of us ever been put ourselves on a drip at least once in life. Have you ever saw any sign of it after recovery? The same happens with the dhi implanter, it does not leave any surgery signs.
*Comparing to the channel technique no adrenalin needs to be injected to decrease bleeding. There is also no need for isotonic liquid or saline serum to swell the haired skin. Therefore swelling after the hair transplant  is very little.

*Ultimately, there is no necrosis-like effect due to adrenaline injection in the Dhi hair transplantation.
*Comparing to other methods, the shock popping rate is considerably low (the reason why adrenaline is not used).

Is the Dhi Hair Transplant More Expensive Thank FUE?

Hair transplant with pen implanter is more expensive than other methods, and the cost of the equipment is higher as well. Here is a list of reasons:

  • The needle of the pen implanter is single-use. It absolutely must not be used in another patient. Even if you try to re-use the needle, it is not possible because it loses sharpness after some amount of implanted grafts. Approximately 8-10 needles are required to transplant around 2500 grafts. The average cost of a needle is 25 USD and for one procedure at least 8 needles are needed. The total price of these 8 needles is 200 USD. On the other hand, in channel method (FUE) blades which cost few cents are used. In addition to that, a pen implanter costs around 150 USD without a needle. 4-6 pens are needed for one surgery (implanter pens are not disposable). The Dhi transplant is more expensive compared to the FUE.
  • Qualified doctor’s assistants are required for the Dhi hair transplantation. In many cases, the reason for unsuccessful outcomes is the lack of the technical knowledge and experience of a doctor and his assisting personnel. Assistant placing grafts into the pen should be highly qualified, which impacts the total surgery cost.
  • If we are not mistaking, some clinics offer a transplant of 5000-6000 grafts per day with the classic method. However, transplantation of more than 2000-2500 grafts with pen implanter at once is not appropriate. Therefore, implanting 5000-600 grafts may take up to 3 days.
  • Based on the reasons listed above, it is normal that the Dhi hair transplantation is a little more expensive than the classical method. Due to legal restrictions, we can’t publish our rates on the website. Please contact us to get the price at 0090 533 247 1990 ( available on WhatsApp).

Rewies the Dhi Hair Transplant

We already mentioned the advantages and disadvantages of this method. You can easily access to many forums of people who experienced transplantation on the internet. You will find a lot of forums with comments and results of Turkish and foreign patients who had been operated by Dr. Hakan Doganay. As an example, you can take a look at our YouTube video about a patient who had a hair transplant. There are also other videos on our channel.

What Should be Paid Attention to When Searching Information About the Pen Implanter Method?

The Dhi hair transplantation method first started operating by Dr. Hakan Doganay in Turkey yet many clinics promote it as a new technique nowadays. We would like to share some questions for one, who is thinking about the Dhi.

  • Is the doctor active in the pen implanter technique? If yes, what is his experience?
  • Is the operation made with pen implanter from the beginning to the end or any other tools are included?
  • Is assisting personnel qualified enough for the pen implanter transplantation? Where did the assistants get an education?
  • Where can I examine the outcomes of the hair transplant? Are there any real examples?
  • Are the single-use needles sterile?

Frequently Asked Questions

What are the Disadvantages of DHI Hair Transplantation?

Together with the benefits of the Dhi hair transplantation method, there are also some disadvantages. Here they are:
As mentioned previously, the Dhi method requires special technique knowledge. If a doctor does not have enough technical skills, the result of the transplantation may be disappointing.
It is the most expensive transplantation method, compared to others.
The surgery should be operated by a doctor only. In the channel method, the assistants may help to stretch the skin at the sides. If a transplant is made by the pen method, only a doctor must stretch the skin. Transplantation of more than 2000-2500 grafts is not acceptable in a single session

Is Dhi Better Than FUE?

In short, yes, it is. There are many benefits of the Dhi technique comparing to the FUE. The most significant ones are density and unshaven hair transplantation possibility.

Does the Dhi Hair Transplant Hurt?

Local anesthesia is applied before the operation, so you do not feel any pain during the surgery. You can find more information in the article about the best hair transplantation method.

How Much Does the Dhi Hair Transplant Cost?

You can find our treatment options on this page.

What Is the Best Dhi Hair Transplant in Turkey

We have prepared some guidelines for you to choose the best clinic.

Dhi Hair Transplants Results Month by Month

You can find entire recovery stages on our website. Moreover, we have posted a few stories of our patients from 2.500 to 10.000 grafts hair implantation.


  1. Survival Rate According to Grafted Density of Korean One-Hair Follicular Units with a Hair Transplant Implanter: Experience with Four Patients American Society for Dermatologic Surgery, Inc. Dermatol Surg 2006;32:815–818
  2. Graft Placement Using the Dull Needle Implanter (DNI) Technique https://www.ishrs-htforum.org/content/27

1 thought on “Dhi Hair Transplant”

  1. Its very informative and loaded with practical solutions we encounter in a hair transplant. Thanks so much.

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