"I get cervico genic headaches. I have a one to one ratio spray of CBD to THC. Each spray delivers about 2 1/2 mg. How much should I use? Two sublingual sprays doesn’t seem to help much. "
You may not experience the results you would like to experience with the medicine you have.
I think you could obtain better results for your headaches by doing a topical CBD balm along the base of your skull and down your neck, wait five minutes and apply another layer. In addition you may want to use a 4 : 1, CBD: THC spray in the mouth for pain relief. This might help your headaches more then your current medication but you could use your current medication to go to sleep but it likely will take two or more sprays in the mouth.
Good luck, headaches are very frustrating. Be certain you’re well hydrated with water.