CBD and Metoprolol (e.g. Lopressor, Toprol-XL, Beloc-Zok, Metohexal)
David ReichUpdated:Key points at a glance:
CBD may interact with metoprolol. Metoprolol is primarily broken down by the CYP2D6 enzyme. CBD can influence CYP450 enzymes and may slightly lower blood pressure. As a result, metoprolol levels in the body may increase. Possible effects include dizziness, tiredness, low blood pressure and a slow pulse. The potential risk may be higher when combined with other blood pressure medicines, CYP2D6 inhibitors or in people with liver problems. Use only after consulting a doctor, start with a low amount and monitor your values closely.
An increasing number of people are interested in cannabidiol (CBD) – including those who are already taking medicines such as metoprolol. This article explains in clear terms how CBD and metoprolol may interact, which risks should be considered and how to proceed cautiously. The aim is to provide a sound basis for discussion with your doctor.
Metoprolol in brief (CYP2D6, uses)
Metoprolol is a beta-blocker used in the management of high blood pressure, cardiac arrhythmias, angina pectoris and for heart protection. It slows the heart rate and lowers blood pressure by reducing the effect of stress hormones (e.g. adrenaline) on the heart. The active substance is mainly broken down in the liver via the enzyme CYP2D6. There are immediate-release (IR) preparations and modified-release preparations (e.g. “-Zok”), which provide a more even effect over time.
CBD: brief overview for people taking metoprolol
CBD interacts with the endocannabinoid system and is often associated with calming effects. Important in the context of metoprolol and other beta-blockers: CBD may inhibit certain liver enzymes in the CYP450 system (including CYP3A4; there are also indications for CYP2D6) and has been associated in studies with a slight reduction in blood pressure.
CBD may influence liver enzymes (CYP2D6, CYP3A4) that are involved in the metabolism of prescription medicines such as metoprolol, and has been linked with small blood pressure reductions. This combination should therefore be approached cautiously and under medical supervision.
CBD and beta-blockers: how can interactions arise?
Role of CYP2D6, CYP3A4 and CBD metabolism
Metoprolol is mainly broken down via the liver enzyme CYP2D6. CBD may inhibit enzymes of the CYP450 system that are important for drug metabolism (especially CYP3A4; in vitro also CYP2D6). If CYP2D6 is inhibited, metoprolol may be broken down more slowly. A possible consequence is higher metoprolol levels in the blood and, in turn, more pronounced side effects such as low blood pressure, dizziness, marked tiredness or a very slow pulse (bradycardia).
The extent of this potential CBD drug interaction can vary from person to person – among other things due to genetic differences in CYP2D6, liver function, CBD dose and the use of other medicines that inhibit CYP2D6 (e.g. some antidepressants).
Additive effects on blood pressure and pulse
Independently of the enzyme mechanism, CBD has been associated in small studies with a slight reduction in blood pressure. In combination with a beta-blocker such as metoprolol, additive effects are possible: blood pressure and pulse may fall more than expected. The risk may increase if other blood pressure-lowering medicines are also being taken.
CBD may both slow the breakdown of metoprolol (via CYP enzymes) and add to its blood pressure and pulse-lowering effects. This can increase the likelihood of side effects such as dizziness, low blood pressure and a very slow pulse.
Interactions between CBD and metoprolol
Metoprolol is mainly broken down via CYP2D6. CBD may inhibit enzymes of the CYP450 system (including CYP3A4; in vitro also CYP2D6). This can mean that metoprolol is broken down more slowly – with a possible increase in the frequency or intensity of side effects such as low blood pressure, dizziness, marked tiredness or a very slow pulse.
Because CBD itself has been associated with slight reductions in blood pressure, additive effects are possible when CBD and metoprolol are taken together. The extent of any interaction depends on dose, formulation, individual enzyme profile, liver function and concomitant medication.
Read our article here on how medicines and CBD may interact
Use the interaction check to get an initial impression of potential risks and to prepare for your medical appointment:
💊 Medication Finder
We have analysed the interactions between CBD and 140 medications und Medikamentenarten analysiert. You can view the full overview here or use the search below to find your specific medication.
CBD and metoprolol may interact through shared liver enzyme pathways (CYP2D6/CYP3A4) and through their combined effects on blood pressure and heart rate. Use the interaction checker as a starting point, then discuss the results with your doctor or pharmacist.
Can I take CBD with metoprolol?
This may be possible, but only after discussing it with a doctor. An individual assessment (dose, other medicines, liver function, treatment goals) is important. Do not stop taking metoprolol or change your doses on your own initiative.
Who may be at higher risk?
- High metoprolol dose or modified-release preparations without dose adjustment
- Concurrent use of other CYP2D6 inhibitors (e.g. paroxetine, fluoxetine)
- Liver impairment or older age
- Combination with other blood pressure-lowering medicines (e.g. ACE inhibitors, calcium channel blockers, diuretics)
How can you recognise problems? (Self-monitoring)
- Measure and record blood pressure and pulse regularly at fixed times (e.g. morning/evening, same arm, after a rest period)
- Watch out for dizziness, light-headedness, a tendency to faint, unusual tiredness, shortness of breath, cold hands/feet
- Warning signs: very slow pulse, persistent dizziness, a tendency to faint – seek medical assessment
What can happen? – overview
| Effect | Possible cause | What you can observe/check |
|---|---|---|
| More pronounced dizziness | Increased metoprolol level due to CYP inhibition by CBD | Measure blood pressure/pulse, compare sitting and standing blood pressure |
| Very slow pulse (bradycardia) | Additive effect on heart rate + slower breakdown of metoprolol | Check resting pulse; if the pulse is very slow, seek medical assessment |
| Marked tiredness | Stronger beta-blocker effect due to higher metoprolol exposure | Note any relationship to dosing times |
| Circulatory problems when standing up | Additional blood pressure reduction associated with CBD and metoprolol | Stand up slowly, record your readings |
Practical tips for safer use
- Consult your doctor before starting CBD (review metoprolol dose, other medicines, liver function tests and target blood pressure/pulse)
- Start with a low CBD amount and increase gradually, if at all, with close monitoring
- Consider different formulations: oils tend to act more quickly; edibles more slowly and for longer. Topical products generally have limited systemic effects
- Do not rely on taking CBD and metoprolol at different times – enzyme inhibition (e.g. of CYP3A4 or CYP2D6) can last longer than the immediate effect
- Record dosing times, amounts, blood pressure/pulse and symptoms – this can be useful for your medical appointment
Formulations and what they mean
| Form | Onset of effect (approx.) | Duration of effect | Relevance for interactions (qualitative) |
|---|---|---|---|
| Oil/tinctures (sublingual) | 15–45 minutes | 2–6 hours | moderate |
| Capsules/edibles | 1–3 hours | 6–8+ hours | moderate to high |
| Inhalation/vape | Minutes | 2–3 hours | moderate |
| Topicals (ointments/creams) | local | local | low (limited systemic absorption) |
Discussion checklist for your medical appointment
- Current metoprolol dose and preparation (IR or modified-release), dosing times
- All other medicines/supplements (including antidepressants, blood pressure-lowering medicines)
- Liver function tests/liver disease, alcohol habits
- Your target values for blood pressure and pulse
- Planned CBD form, approximate dosing times and reasons for considering use
- Monitoring record (blood pressure/pulse, symptoms)
Before combining CBD and metoprolol, prepare for your appointment by listing all medicines, noting your blood pressure and pulse readings, and clarifying your goals for CBD use. This helps your doctor assess potential CBD–metoprolol interactions more accurately.
Side effects at a glance
CBD – common and less common effects
Commonly reported effects include tiredness, dry mouth, dizziness, changes in appetite and gastrointestinal issues (e.g. nausea, diarrhoea). CBD may influence liver enzymes; medical advice is particularly important in the context of liver disease or when CBD is used alongside prescription medicines. Caution is advised when it is taken together with other sedating substances (e.g. benzodiazepines, alcohol) – increased drowsiness is possible.
Metoprolol – common and less common effects
Side effects of metoprolol
Common side effects include tiredness, dizziness, slow pulse (bradycardia), cold hands and feet, gastrointestinal discomfort and sleep disturbances.
Less common, but important: pronounced bradycardia or AV block (very slow or irregular pulse), breathing difficulties in asthma/COPD, low mood. In diabetes, beta-blockers can mask some warning signs of low blood sugar (e.g. palpitations). Seek medical advice if you notice such symptoms.
Important safety notice: This article does not replace medical advice. Do not change or stop your medication without medical supervision. In the event of persistent dizziness, very slow pulse, a tendency to faint or breathing problems, seek medical help immediately.
Conclusion
CBD and metoprolol may interact via enzyme inhibition (particularly CYP2D6/CYP3A4) and through additive effects on blood pressure and pulse. With caution, careful monitoring and medical supervision, an individual approach may be possible. Use the interaction check, keep track of your readings and make decisions together with your doctor.
Disclaimer: This article is for information purposes only and does not replace medical advice. Do not change medicines or dosages without consulting your doctor. No claims are made regarding the treatment or cure of illnesses.