What do you hope to accomplish with the CBD oil? It is unlikely to reduce vertigo but some folks have had success with it for reducing stress/anxiety which then helps with reduced dizziness and other MD symptoms. I take Betahistine and tried CBD oil and had no problem. The CBD did not do much for me. I'm about to start on medical marijuana which I've heard is better for reducing stress/anxiety then CBD. MM can also be used safely with Betahistine *.
* One important note.....if you are taking Betahistine be sure NOT to take an ORAL antihistamine for allergy. If you do it will neutralize the Betahistine and you will receive no benefit from it. If you need an antihistamine take it via NASAL SPRAY (not through mouth) and/or take a steroid nasal spray like Flonase which is not an antihistamine. Good luck