The chemist where prescriptions for LDN are sent to, whether via an NHS GP or privately.
For private prescriptions, which requires an initial "consultation":
About Private Prescriptions:
http://dicksonchemist.co.uk/new/about-private-presciptions/
New PRIVATE Patients Registration
http://dicksonchemist.co.uk/new/private-patients-registration/
Request for consultation for Low Dose Naltrexone (LDN)
https://docs.google.com/forms/d/e/1FAIpQLSd1hfdevDYzoqJbKG4y5q33F2ynfFBrixJB9pb91XHTedw_sg/viewform