I stumbled across this information on CBD oil:
www.ontrackdiabetes.com/live-well/diabetes-management/cbd-oil-what-know-you-try-it
Before You Buy
Read the lab report before purchasing any CBD-related product. Lab studies of CBD oils have found compounds in some that shouldn't be there including dangerous synthetic cannabinoids, THC (the psychoactive component of marijuana responsible for making you feel high) and heavy metals like lead. Researchers have also found a too-low and too-high concentrations of CBD in some products. The label may not give you any of this information—so it's wise to request a lab report before you buy a CBD oil product, Konieczny recommends.
"I think using manufacturers that are submitting to testing or pharmacies that are trying to carry CBD and have done some vetting may be the answer," Dr. Bhatia says.
#2. Skip CBD oil if you take the certain medications
Cannabidiol is a "potent inhibitor" of two key liver enzymes—CYP3A4 and CYP2D6—that break down many prescription and over-the-counter medications, according to a report from the District of Colombia Department of Health3. In fact, one of these enzymes, CYP3A4, metabolizes one-fourth of all drugs according to the report. "Cannabinoids do interact with some pharmaceutical drugs," she notes. "It's important to talk with your doctor or with a healthcare practitioner familiar with cannabis before using it."
By interfering with metabolism in the liver, CBD could increase blood levels of these drugs, according to the report: Macrolide antibiotics, blood pressure-lowering calcium channel blockers, the
cholesterol-lowering statins atorvastatin and simvastatin, antihistamines used for allergy symptoms, anxiety-reducing benzodiazepines, cyclosporine (an immune suppressant used to prevent transplant organ rejection), erectile dysfunction drugs called PDE5 inhibitors including sildenafil, some antiretroviral drugs, antidepressants including selective serotonin reuptake inhibitors and tricyclic antidepressants, beta-blockers (used by people with heart disease), pain-killing opioids including codeine and oxycodone, antipsychotic drugs such as haloperidol, and the blood thinner warfarin.