Why visit a registered trichologist?
It's safe to assume that you would never board a flight if you knew the 'pilot' had not undergone official flight training. You would never take advice from a 'doctor' who wasn't registered with the General Medical Council (in the UK).
For trichologists to be classed as registered they need to have undergone a minimum of two years study along with experiential clinical practice.
Registered trichologists are required to practice by a strict code of ethics which are designed to uphold and enhance the practice of trichology and to help protect members of the public.
You can read the Code Of Professional Practice And Ethics governed by the Institute of Trichologists (London, UK) which was formed in 1902 here (opens in new page).