Cannabidiol (CBD) is a healthy cannabinoid that is found in the cannabis and hemp plants but is also contained in black pepper and turmeric.  CBD has been in the news lately for having many health benefits as we humans possess receptors in our brains for this, it's part of a system called the endocannabinoid system.  One of the most efficient ways to get CBD into our bodies is through vaping.  There is CBD isolate on the market now that is 99.9% pure, this substance is similar in appearance to table salt.  One can mix a gram of CBD isolate with 3ml of Farm to Vape (FTV) and make a very potent CBD e juice at 250mg/ml.  It's probably a better ratio to use 1/2 gram CBD isolate to 3ml of FTV making a 125mg/ml cbd vape mix.