Posted 3/18/2019 10:42 AM (GMT -7)
CBD products can contain trace THC. Federal law limits it to .3% THC, but even with that, you can test positive for THC. I purchased some federally legal hemp flower last year and vaped it for a while. I bought some THC urine tests and did eventually test positive, just by using it. There are also published studies showing that hemp products can result in positive urinalysis. What is going on is that THC metabolites (which are not psychoactive) end up getting stored in fat cells, build up, and then get release if you lose some weight, exercise, etc..
There are, however, some products that purport to be 100% THC free and can provide you with testing to show that. If you have your doctor's consent, I would suggest buying something where you can get the lab report and show it to your doctor. Nevertheless, from batch to batch, one never knows if some THC will remain.
Perhaps your doctor doesn't know that we have an endocannabinoid system, i.e. natural cannabinoids and receptors that are activated by THC as well as CBD. CBD bonds with the CB2 receptor, which regulates cytokine levels. Cytokines play an important role in inflammation and thus by using CBD, you can reduce inflammation (THC does this too via a related mechanism). Here are a few studies...
In short, CBD is not a placebo. It has a well established mechanism of action, one that may or may not benefit you. Note also that CBD has very low oral bioavailability -- between 5-15%. For this reason, I vape it instead of using pills. Another option is sublingual tinctures, but they too aren't great for bioavailability as the liquid usually gets washed away from under your tongue by saliva.