CBD is metabolized in the liver by a family of enzymes known as the cytochrome P-450 system (CYP450). This enzyme group is actually responsible for processing most commonly prescribed pharmaceutical drugs. If the CYP450 system is functioning normally, most drugs have a documented, predictable lifespan within the body—e.g., a drug known to be active for 12 hours should, in healthy person, be active for that amount of time. Genetics and environmental toxicity can also play a role in the efficacy of the CYP450 enzyme family. Saliva tests are now available that can actually measure the health of this system before medications are prescribed.
Many people take more than one medication, and this is where things can get complicated. When multiple drugs are taken, their periods of effectiveness can be disrupted. Some drugs slow down CYP450 metabolism (inhibitors), while others can boost it (inducers). If the metabolism is depressed, higher concentrations of a drug can accumulate in the body to the point of toxicity. If the metabolism is pushed harder, a medication can move through the system too quickly, shorting the intended dosage level.
CBD can inhibit the ability of the CYP450 system to metabolize medications, prolonging the processing of these drugs and therefore their effects. This can result in elevated levels of these drugs in the system, which can lead to overdose or other adverse effects. Here are some common drug types that depend on the CYP450 system for processing and can potentially be affected by CBD:
- Calcium channel blockers
- Immune modulators
- Beta blockers
- HIV antivirals
- HMG-CoA reductase inhibitors (statins)
- Angiotensin II receptor blockers (ARBs)
- Oral hypoglycemic agents
If you’re on medication it’s important to consult with your physician before supplementing with CBD as you might need to adjust dosages or make other changes. You can also ask to have your CYP450 system tested to be sure it is metabolizing everything as it should. The takeaway here should be that CBD, other drugs, and liver health all interact, and that the utmost care should be taken when combining CBD with any other medications.