The NCBI study does mention some potential side effects for cannabidiol, such as the inhibition of hepatic drug metabolism and decreased activity of p-glycoprotein. CBD can indeed interact with a series of pharmaceuticals, as it inhibits the activity of some liver enzymes called cytochrome P450. This family of enzymes metabolizes most of the pharmaceutical drugs used to treat humans.
Lisa Hamilton, a jeweler and doula in Brooklyn, NY, knows about the side effects. She recently tried CBD for the shoulder pain that plagued her five years after an accident. Her doctor certified that she was in chronic pain, which under New York State law allowed her to buy from a state dispensary. One Friday, she swallowed two 10-mg capsules, the amount recommended at the dispensary, then took another two on Saturday. “By Sunday, it felt like I’d gotten hit by a truck. Every muscle and joint ached,” Hamilton says. She cut back to one pill a day the following week, but still felt hungover. She stopped after that.
Low Blood Pressure and Lightheadedness – an effect of CBD that may seem somewhat counterintuitive, an almost immediate (though small) decrease in blood pressure has been reported at the exposure to high doses, causing the associated lightheadedness, albeit not for long periods. Nevertheless, it could be significant for individuals taking blood pressure medication.
Our bodies are thought to produce endocannabinoids by the billions every day. “We always thought the ‘runner’s high’ was due to the release of dopamine and endorphins. But now we know the euphoria is also from an endocannabinoid called anandamide,” its name derived from the Sanskrit word for bliss, says Joseph Maroon, MD, clinical professor and vice chairman of neurosurgery at the University of Pittsburgh Medical Center. We produce these natural chemicals all day, but they fade quickly because enzymes pop up to destroy them. That’s where CBD comes in: By blocking these enzymes, CBD allows the beneficial compounds to linger.