How DHI works — the Choi pen technique
DHI (Direct Hair Implantation) uses a Choi implanter pen — a hollow-needle device loaded with a single extracted follicle. Unlike FUE where channels are pre-created with a blade avant de graft insertion, DHI creates the recipient channel and places the graft simultaneously in a single motion. The surgeon controls angle, direction and depth entirely through pen positioning.
This single-step approach produces two advantages: it eliminates the time gap between channel creation and implantation (reducing risk of channel collapse or contamination); and it provides the surgeon direct, continuous control over the angle of every placed graft.
When DHI is the preferred technique
| Scenario | Best technique | Why |
|---|---|---|
| Thinning zone with existing hair | DHI | No pre-channels — no risk to adjacent follicles |
| Unshaved / no-shave procedure | DHI | Designed for placement between existing hair |
| High-density hairline | DHI | Superior angle precision at leading edge |
| Women with diffuse thinning | DHI | Preserves all existing hair |
| Large session 4,000+ grafts | FUE | Faster at scale |
| Fully bald zone | Either equally | No existing follicles to protect |
DHI results — what patients experience
DHI results at Hairmedico match FUE results in density and naturalness — the technique choice does not affect the final outcome quality, it determines which technical approach is optimal for the specific case. Growth timeline is identical: shock loss weeks 2–5, new growth from months 3–5, 80% density by month 9, final result months 12–14. The DHI advantage is most visible in the hairline naturalness and in the preservation of existing hair in thinning zones.
Frequently Asked Questions
DHI (Direct Hair Implantation) uses a Choi implanter pen that creates a recipient channel and places the graft simultaneously in one motion. Unlike FUE where channels are pre-created, DHI combines these steps, offering superior angle control and enabling placement between existing hairs without shaving.
DHI is best for: patients with existing hair in the recipient zone (thinning rather than fully bald), women with diffuse thinning, patients who cannot shave (unshaved DHI), and anyone requiring very high-precision hairline density work.
No. DHI is performed under local anaesthesia — the scalp is fully numb throughout. At Hairmedico, the Comfort-in needle-free injector eliminates the needle sting of anaesthetic administration, making the entire procedure pain-free.
DHI takes longer per graft than standard FUE because each graft is loaded individually into the Choi pen. A 2,000-graft DHI session typically takes 7–9 hours. Dr. Arslan performs the entire procedure personally.
- International Society of Hair Restoration Surgery. Practice census — global hair restoration statistics.. 2022. fue-europe.com
- Onda M et al. Follicular unit extraction: a systematic review. J Plastic & Aesthetic Chirurgie. 2020. doi.org
- NHS. Hair loss — overview. National Health Service UK. 2023. nhs.uk
- MedlinePlus NIH. Hair transplantation — clinical overview. U.S. National Library of Medicine. 2024. medlineplus.gov
- Bernstein RM. Follicular unit transplantation. Dermatologic Cliniques. 2013. doi.org
All references are peer-reviewed medical literature or official health authority publications. No commercial sources included.
Dr. Arslan Musbeh
- ✓ FUE Europe — Full Member
- ✓ Ministry of Health accredited
- ✓ 17+ years · 3,000+ cases
- ✓ One patient per day
- ✓ Algorithmic FUE™ creator