"Medical cannabis" is a broad term for any sort of cannabis-based medicine used to relieve symptoms.
Many cannabis-based products are available to buy online, but their quality and content is not known. They may be illegal and potentially dangerous.
Some products that might claim to be medical cannabis, such as "CBD oil" or hemp oil, are available to buy legally as food supplements from health stores. But there's no guarantee these are of good quality or provide any health benefits.
And some cannabis-based products are available on prescription as medicinal cannabis. These are only likely to benefit a very small number of patients.
Continue reading: https://www.nhs.uk/conditions/medical-cannabis/