I have been using Adven THC oil and getting good results with my RA pain, which includes nerve pain in shoulder, neck and face.
Its legal and prescribed and reasonable priced £80 for 30mls which is about 40 days dose. I was prescribed at the sapphire clinic, all online appointments as long as you can provide a medical letter outlining the pain and problem. There is a £50 consultation every 8 weeks due to prescribing guidelines.
I have been using weed for years, but was surprised how effective the oil was in dealing with the pain and getting sleep.