Hear From a Professional

Prof. Michael Barnes is a consultant neurologist with over 20 years of experience in medical cannabis and CBD research. He is the author of The Beginner's Guide to Medical Cannabis and one of the UK's leading voices on cannabinoid medicine.

We asked Prof. Barnes some of the most common questions our customers have about CBD — here's what he had to say.

Questions for Prof. Barnes

How did you get into medical cannabis?

I became interested about 20 years ago when patients were coming to my MS clinic saying they were using illegal cannabis and it was making their pain and spasm better. About 50% of the patients were using it. I then became involved in the Sativex development programme with GW Pharma — Sativex was the first licensed cannabis medicine. My interest grew from there.

Do you, or have you, used CBD yourself?

No. Fortunately I am well with no need to use it.

What inspired your latest book?

I felt the public needed a very simple guide to cannabis and its medicinal benefits. Nothing complex — straightforward, honest and easy to read. Hopefully the book has succeeded in that aim.

Why can't companies talk about CBD health benefits?

Because over-the-counter products are deemed food supplements, not registered medicines. If they are not official medicines, the producer cannot make medical claims. That does not mean CBD has no medicinal value — it simply means producers cannot say so.

Why do some people feel no effects when using CBD oil?

No medicine is guaranteed to be successful. Some people — around 10–20% — do not respond well, or at all.

What strength oil should I start with?

It is always best to start low and go slow. I usually suggest starting at around 20mg daily and building up by 10mg per week, to a usual dose of between 60–100mg daily. Working in milligrams rather than percentages tends to be clearer. Start with a low-strength oil and increase if needed.

How long before I feel the effects of CBD oil?

It varies greatly. Most people notice an effect within a few days. For some — especially children using CBD for epilepsy — it can take up to six weeks.

Where do you hope to see the CBD and medical cannabis industry in 10 years?

I hope it will have expanded significantly. I want CBD to be an accepted, widely available medicine and wellness product, and for its medicinal properties to be better recognised — so that producers can tell the public what it is genuinely good for.

What is the one thing you want people to know about CBD?

It is a very safe product. No medicine or wellness product is entirely without side effects, but CBD really is very safe.