From
Practitioner
to
Developer.
How hands-on tissue experience shaped a new technology.
Turning Point
rehaar started unplanned. During flight school, a hair transplant in 2002 fell short of what was expected. An early procedure raised technical questions that took years to resolve.
Aviation was a discipline where systematic thinking, checklists, and uncompromising precision were not optional. They were the baseline. That mindset later became the foundation of instrument development: every detail counts, every process needs a system.
What began as a personal experience became the starting point for a question that would not go away: Why do such significant quality differences arise despite similar methods?
What followed was not driven by a business plan. It was driven by a problem that kept surfacing. The deeper the process analysis went, the clearer a pattern became: quality differences in FUE do not primarily stem from the method—they stem from the instrument. When the tool does not adequately support the process, outcomes fall short of the method’s full potential.
That became the central insight that shaped everything after: a method can only be as precise as the instrument that executes it. That realization set the direction.
An Unconventional Path
Starting in 2009, Halil Senguel trained under internationally recognized specialists and immersed himself in hair transplant technique. In 2014, he opened his own specialized practice as a certified practitioner.
As a certified practitioner (Heilpraktiker) under German law, he had no access to prescription medication, including the local anesthetics commonly used in standard FUE procedures. A conventional FUE approach was not an option. The process had to be rethought from scratch. The result was a technical decision: less invasiveness, smaller diameters, and shallower penetration depth, with the goal of minimizing bleeding events and maintaining procedural stability under these constraints.
Out of that constraint came a method that was extremely precise and tissue-sparing, but came at a cost: it was slower, more demanding, and demanded precision at every step. Over the years, this approach was refined under real-world conditions, made reproducible, and systematically documented.
It was manageable because the execution had been honed and refined over years of real-world practice. But it was tied to a specific way of working and could not scale broadly. The limiting factor was the instruments available on the market, which did not adequately support the critical part of the process.
In late 2024, Halil Senguel fully ended his active clinical practice as a certified practitioner to focus on instrument development and training. The following footage is archival and informs our process analysis.
The Insight
The bottleneck became clear: it is not the method that needs further development—it is the tool. Even with a high level of technical competence, results remain bound by the physical limitations of the instrument. The solution: an instrument that translates the operator’s existing skill more precisely and enables more consistent outcomes.
Since then, the focus has been entirely on research, instrument development, and industrialization. rehaar develops microsurgical precision instruments for hair transplantation—designed for serial production, packaging, and clinical process integration. Specifications are coordinated in a partner context, under NDA where required.
More about Instruments →A good instrument makes every physician better. A bad instrument limits even the best.Halil Senguel, Founder, rehaar®
rehaar® Today
Under rehaar GmbH & Co. KG, the company operates across three divisions:
Instruments
Microsurgical precision instruments for hair transplantation. Solving physical problems through advanced instrument design.
Medical Center
Turnkey clinical infrastructure for physicians: fully equipped treatment rooms, marketing, patient acquisition, and practice management in Düsseldorf.
Academy
Training, implementation, and workflow standards for clinics and teams. Reproducible quality in FUE surgery.
Leadership
Halil Senguel
15 years of experience in hair transplantation. Focus on process analysis, defect pattern identification, and instrument development.
Michael Mennekes
Long-standing business partner. Co-founded rehaar GmbH & Co. KG in 2019.
Milestones
Began systematic analysis
Opened specialized practice
Founded rehaar GmbH & Co. KG
Halil Senguel ended active clinical practice to focus entirely on instrument development and training
Pilot phase and industrial partnerships