CBD Drug Interactions: The Complete Safety Guide (2025)
- Travis C
- Apr 18, 2024
- 13 min read
Updated: Dec 26, 2025
Evidence-Based Information to Help You Use CBD Safely with Your Medications
⚠️ KEY TAKEAWAY: CBD can interact with over 600 medications by affecting how your liver processes drugs. Always consult your healthcare provider before using CBD if you take any prescription medications.
Table of Contents
Introduction: Why CBD Drug Interactions Matter
CBD (cannabidiol) has become one of the most popular natural wellness supplements in America, with millions of people using it daily for sleep, anxiety, pain relief, and overall balance. At Cannagea, we're committed to your safety and believe that informed customers are empowered customers.
While CBD is generally well-tolerated, it's not without considerations—especially if you take prescription or over-the-counter medications. Research shows that CBD can interact with more than 600 medications, affecting how they're processed in your body. This comprehensive guide will help you understand these interactions so you can make informed decisions about your wellness routine.
This guide is designed for educational purposes and should not replace medical advice. Always consult with your healthcare provider or pharmacist before adding CBD to your routine, especially if you take any medications.
How CBD Interacts with Medications: The Science Explained
The Cytochrome P450 Enzyme System
To understand CBD drug interactions, you need to know about your liver's cytochrome P450 (CYP450) enzyme system. This family of enzymes is responsible for metabolizing—or breaking down—approximately 60% of all clinically prescribed medications.
CBD is primarily metabolized by two specific enzymes in this family: CYP3A4 and CYP2C19. Here's where it gets important: CBD doesn't just get processed by these enzymes—it can also inhibit them, meaning it can slow down or block their activity.
What Happens When CBD Inhibits Drug Metabolism
When CBD inhibits CYP450 enzymes, medications that rely on those same enzymes for metabolism may not be broken down as efficiently. This can lead to:
Higher medication levels in your bloodstream – Even at your normal dose, you may have more of the drug in your system than intended
Prolonged drug effects – Medications may stay active in your body longer than expected
Increased risk of side effects – Higher concentrations can amplify both therapeutic and adverse effects
Reduced effectiveness of "prodrugs" – Some medications need to be metabolized to become active; CBD can interfere with this activation
The Grapefruit Rule: A Simple Safety Heuristic
Here's a helpful rule of thumb: If your medication has a grapefruit warning on the label, you should be cautious about using CBD.
Grapefruit contains compounds called furanocoumarins that inhibit CYP3A4—the same enzyme that CBD affects. The FDA has identified more than 85 medications that interact with grapefruit. While the mechanisms aren't identical, the grapefruit warning is a useful indicator that your medication may also interact with CBD.
💡 Pro Tip: Check your medication bottle or package insert for grapefruit warnings. If you see one, have a conversation with your doctor or pharmacist before using CBD.
Medications with Known CBD Interactions
The following categories of medications have documented or potential interactions with CBD. This is not an exhaustive list, but covers the most commonly prescribed drug classes.
Drug Category | Common Examples | Interaction Risk |
Blood Thinners | Warfarin, Rivaroxaban, Apixaban | HIGH |
Anti-Seizure Medications | Clobazam, Valproate, Lamotrigine | HIGH |
Benzodiazepines | Xanax, Valium, Klonopin, Ativan | HIGH |
Antidepressants (SSRIs) | Prozac, Zoloft, Lexapro | MODERATE |
Antidepressants (Other) | Wellbutrin, Trazodone | MODERATE |
Opioid Pain Medications | Codeine, Morphine, Oxycodone | MODERATE |
Heart Medications | Beta-blockers, Calcium Channel Blockers | MODERATE |
Thyroid Medications | Levothyroxine (Synthroid) | MODERATE |
Corticosteroids | Prednisone, Hydrocortisone | MODERATE |
NSAIDs | Ibuprofen, Naproxen (high doses) | LOW |
Immunosuppressants | Cyclosporine, Tacrolimus | HIGH |
Risk Level Definitions:
HIGH: Well-documented interactions; medical supervision required
MODERATE: Potential interactions; consult healthcare provider
LOW: Limited evidence of interaction; use caution at high doses
Blood Thinners (Anticoagulants)
Blood thinners like warfarin (Coumadin) are among the most concerning medications to combine with CBD. CBD can enhance the blood-thinning effects of these medications by inhibiting their metabolism, potentially increasing the risk of bleeding, bruising, and preventing wounds from healing properly.
If you take blood thinners: Do not use CBD without first discussing it with your doctor. If your physician approves CBD use, you may need more frequent INR monitoring to ensure your blood clotting stays within a safe range.
Anti-Seizure Medications
Ironically, while CBD (as Epidiolex) is FDA-approved for treating certain seizure disorders, it can interact significantly with other anti-epileptic drugs. CBD increases levels of clobazam's active metabolite (N-desmethylclobazam) and can affect levels of valproate, lamotrigine, topiramate, and others.
Important Note: These interactions are well-studied because of Epidiolex clinical trials. If you have epilepsy and are interested in CBD, work closely with your neurologist who can monitor drug levels and adjust doses as needed.
Benzodiazepines
Benzodiazepines (Xanax, Valium, Klonopin, Ativan) are commonly prescribed for anxiety—the same condition many people use CBD to address. CBD can prevent these medications from being properly metabolized, potentially leading to increased sedation, drowsiness, and other side effects.
⚠️ Warning: Combining CBD with benzodiazepines may cause excessive drowsiness. Never drive or operate machinery until you know how this combination affects you.
Antidepressants
Many antidepressants, including SSRIs (Prozac, Zoloft, Lexapro) and others (Wellbutrin, Trazodone), are metabolized by liver enzymes that CBD can inhibit. This may increase drug levels in your body, potentially amplifying both therapeutic effects and side effects like dizziness, drowsiness, and nausea.
If you're considering CBD for mood support: Talk to your prescribing doctor first. They may recommend starting with a very low CBD dose and monitoring for any changes in how you feel.
Factors That Influence Your Interaction Risk
Not everyone faces the same level of risk from CBD-drug interactions. Several factors determine how likely you are to experience an interaction and how severe it might be:
1. CBD Dosage
Dose matters significantly. Research suggests that clinically meaningful interactions are more likely at CBD doses above 300mg daily. The typical wellness dose of 20-50mg daily carries a much lower interaction risk than the high doses used in clinical trials (often 5-20mg per kg of body weight).
2. Method of Consumption
How you take CBD affects how quickly it reaches your bloodstream and how concentrated it becomes:
Inhaled CBD (vaping): Enters blood fastest, reaches highest peak concentration, highest interaction potential
Sublingual CBD (tinctures held under tongue): Moderate absorption speed and concentration
Oral CBD (gummies, capsules): Slowest absorption, lower peak concentration, lower interaction risk
Topical CBD (creams, lotions): Minimal systemic absorption, lowest interaction potential
3. Your Genetics
Approximately 7% of people carry genetic variants that make them "slow metabolizers." If you're a slow metabolizer, CBD can cause a greater buildup of both CBD and other medications in your body, increasing interaction risk.
4. Age and Liver Function
Older adults often have reduced liver function and slower drug clearance. This means medications (and CBD) may stay in the body longer, increasing the chance of interactions. If you're over 65 or have liver issues, start with lower CBD doses and increase gradually.
5. Number of Medications (Polypharmacy)
Taking multiple medications (five or more) significantly increases your interaction risk. Each additional medication that uses CYP450 enzymes adds complexity to how your body processes everything.
How to Use CBD Safely with Medications
If you take medications and want to try CBD, follow these evidence-based guidelines:
Step 1: Consult Your Healthcare Provider
Before starting CBD, talk to your doctor or pharmacist about:
All prescription and over-the-counter medications you take
Any supplements or herbal products you use
Your interest in trying CBD and why
The specific CBD product you're considering (bring it to your appointment if possible)
Your pharmacist can be an especially valuable resource—they have access to drug interaction databases and can quickly identify potential concerns.
Step 2: Start Low and Go Slow
If your healthcare provider approves CBD use, start with the lowest effective dose:
Begin with 10-20mg of CBD daily
Wait 1-2 weeks before increasing
Increase by small increments (5-10mg)
Keep a journal of doses and any effects you notice
Step 3: Consider Timing
While not always practical, spacing out CBD and medication doses by 2-4 hours may help reduce peak interaction potential. Ask your healthcare provider if timing adjustments make sense for your situation.
Step 4: Choose Quality Products
Product quality matters for safety. Look for:
Third-party lab testing (COAs): Verifies CBD content and screens for contaminants
Clear labeling: Exact CBD content per serving should be listed
Reputable source: Companies that are transparent about their sourcing and manufacturing
At Cannagea CBD, every product is third-party lab tested and comes with a Certificate of Analysis (COA) so you know exactly what you're getting.
Step 5: Monitor for Changes
Watch for warning signs that may indicate an interaction:
Unusual drowsiness or sedation
Changes in medication effectiveness
New or worsening side effects
Unusual bruising or bleeding (if on blood thinners)
Digestive changes
If you notice any concerning changes, stop CBD and contact your healthcare provider.
Special Considerations for Specific Groups
Seniors
Older adults are at higher risk for CBD-drug interactions due to:
Reduced liver function with age
Higher likelihood of taking multiple medications
Changed body composition affecting drug distribution
Recommendation: Seniors should start with very low doses (5-10mg) and increase more gradually than younger adults. Always involve your healthcare team.
People with Liver Conditions
Since CBD is processed primarily by the liver, people with liver disease or elevated liver enzymes should exercise extra caution. Clinical trials of Epidiolex (prescription CBD) showed dose-dependent liver enzyme elevations in some patients.
Recommendation: If you have liver issues, discuss CBD with your gastroenterologist or hepatologist. They may recommend liver function monitoring if you proceed with CBD.
Pregnant or Nursing Women
The FDA strongly advises against using CBD during pregnancy or breastfeeding. Limited research exists, but potential risks to fetal development and nursing infants are concerning.
⚠️ Recommendation: Avoid CBD if you are pregnant, trying to become pregnant, or breastfeeding.
Frequently Asked Questions
Can I take CBD with my blood pressure medication?
Many blood pressure medications (beta-blockers, calcium channel blockers) are metabolized by CYP450 enzymes and may interact with CBD. Additionally, CBD itself may have blood-pressure-lowering effects. Consult your cardiologist before combining CBD with any cardiovascular medication.
Is CBD safer than my anxiety medication?
"Safer" depends on individual circumstances. CBD may offer benefits with a different side effect profile than prescription anxiety medications, but it can also interact with them. Never stop or reduce prescribed medications without your doctor's guidance. If you're interested in exploring CBD for anxiety, discuss it as a potential complement to—not replacement for—your current treatment plan.
How long should I wait between taking CBD and my medications?
There's no universal answer, but spacing doses by 2-4 hours may help reduce peak interaction potential. However, since both CBD and medications can stay in your system for extended periods, timing alone doesn't eliminate interaction risk. Work with your healthcare provider to determine the best approach for your specific medications.
Are topical CBD products safer regarding drug interactions?
Topical CBD products (creams, lotions, balms) have minimal systemic absorption, meaning very little CBD enters your bloodstream. This makes them the lowest-risk option for drug interactions. However, some absorption can occur, especially with large application areas or damaged skin. If you're on high-risk medications, even topicals warrant a conversation with your healthcare provider.
Will my doctor know about CBD drug interactions?
Healthcare providers vary in their CBD knowledge. Many are becoming more informed as CBD use increases. If your doctor seems unfamiliar, your pharmacist may be a better resource—they have access to comprehensive drug interaction databases and specialize in medication safety.
Can I use CBD if I take Tylenol (acetaminophen)?
Acetaminophen is metabolized differently than most CYP450 substrates, so the interaction risk is lower. However, both acetaminophen and CBD are processed by the liver, so combining high doses of both could theoretically stress liver function. Occasional use of regular-strength Tylenol with typical CBD doses is unlikely to be problematic, but chronic high-dose use of either warrants caution.
Conclusion: CBD Can Be Part of a Safe Wellness Routine
CBD offers promising potential for supporting sleep, managing stress, and promoting overall wellness. However, like any bioactive compound, it requires thoughtful use—especially if you take medications.
The key takeaways from this guide:
CBD interacts with medications by affecting liver enzymes that metabolize over 60% of prescription drugs
The grapefruit rule is a useful heuristic: if your medication warns against grapefruit, be cautious with CBD
Always consult your healthcare provider before using CBD if you take any medications
Start low and go slow to minimize risks while finding your optimal dose
Quality matters —choose third-party tested products from reputable sources
At Cannagea, we're committed to your wellbeing. Every product we offer is crafted from Colorado-grown hemp, rigorously third-party tested, and backed by our commitment to quality and transparency. We believe you deserve to make informed decisions about your health, and we're here to support you every step of the way.
Have questions about CBD and your specific medications? Feel free to contact our team or visit our Fort Collins store where our knowledgeable staff can help guide you.
Medical Disclaimer
This content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any new supplement, including CBD, especially if you take prescription medications or have underlying health conditions. These statements have not been evaluated by the Food and Drug Administration. CBD products are not intended to diagnose, treat, cure, or prevent any disease.
References
Nasrin S, et al. (2021). Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes. Clinical Pharmacology & Therapeutics.
Brown JD, Winterstein AG. (2019). Potential Adverse Drug Events and Drug–Drug Interactions with Medical and Consumer Cannabidiol (CBD) Use. Journal of Clinical Medicine.
Gaston TE, et al. (2017). Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia.
Kocis PT, Vrana KE. (2020). Delta-9-Tetrahydrocannabinol and Cannabidiol Drug-Drug Interactions. Medical Cannabis and Cannabinoids.
Harvard Health Publishing. (2021). CBD and other medications: Proceed with caution. Harvard Medical School.
https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743#
FDA. (2020). What You Need to Know (And What We're Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD. U.S. Food & Drug Administration.
Some medications that may be affected include:
Brivaracetam (Briviact)
Caffeine
Carbamazepine (Tegretol)
Citalopram (Celexa)
Clobazam (Onfi)
Eslicarbazepine (Aptiom)
Everolimus (Zostress)
Fluoxetine (Prozac)
Lithium
Medications metabolized by various liver enzymes (Cytochrome P450 enzymes)
Methadone (Dolophine)
Rufinamide (Banzel)
Sirolimus (Rapamune)
Stiripentol (Diacomit)
Tacrolimus (Prograf)
Tamoxifen (Nolvadex)
Topiramate (Topamax)
Valproate
Warfarin
Zonisamide
Some moderate interactions are listed below:
Sedative medications (CNS depressants)
CBD might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking CBD with sedative medications might cause breathing problems and/or too much sleepiness.
Medications changed by the liver (Cytochrome P450 1A1 (CYP1A1) substrates)
Some medications are changed and broken down by the liver. CBD might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
Brivaracetam (Briviact)
Brivaracetam is changed and broken down by the body. CBD might decrease how quickly the body breaks down brivaracetam. This might increase levels of brivaracetam in the body.
Caffeine
Caffeine is changed and broken down by the body. CBD might decrease how quickly the body breaks down caffeine. This might increase levels of caffeine in the body.
Carbamazepine (Tegretol)
Carbamazepine is changed and broken down by the body. CBD might decrease how quickly the body breaks down carbamazepine. This might increase levels of carbamazepine in the body and increase its side effects.
Citalopram (Celexa)
Citalopram is changed and broken down by the body. CBD might decrease how quickly the body breaks down citalopram. This might increase levels of citalopram in the body and increase its side effects.
Clobazam (Onfi)
Clobazam is changed and broken down by the liver. CBD might decrease how quickly the liver breaks down clobazam. This might increase the effects and side effects of clobazam.
Eslicarbazepine (Aptiom)
Eslicarbazepine is changed and broken down by the body. CBD might decrease how quickly the body breaks down eslicarbazepine. This might increase levels of eslicarbazepine in the body by a small amount.
Everolimus (Zostress)
Everolimus is changed and broken down by the body. CBD might decrease how quickly the body breaks down everolimus. This might increase levels of everolimus in the body.
Fluoxetine (Prozac)
Fluoxetine is changed and broken down by the body. In some people, CBD might decrease how quickly the body breaks down fluoxetine. This might increase levels of fluoxetine in the body.
Lithium
Taking higher doses of CBD might increase levels of lithium. This can increase the risk of lithium toxicity.
Methadone (Dolophine)
Methadone is broken down by the liver. CBD might decrease how quickly the liver breaks down methadone. Taking cannabidiol along with methadone might increase the effects and side effects of methadone.
Rufinamide (Banzel)
Rufinamide is changed and broken down by the body. CBD might decrease how quickly the body breaks down rufinamide. This might increase levels of rufinamide in the body by a small amount.
Sirolimus (Rapamune)
Sirolimus is changed and broken down by the body. CBD might decrease how quickly the body breaks down sirolimus. This might increase levels of sirolimus in the body.
Stiripentol (Diacomit)
Stiripentol is changed and broken down by the body. CBD might decrease how quickly the body breaks down stiripentol. This might increase levels of stiripentol in the body and increase its side effects.
Tacrolimus (Prograf)
Tacrolimus is changed and broken down by the body. CBD might decrease how quickly the body breaks down tacrolimus. This might increase levels of tacrolimus in the body.
Tamoxifen (Nolvadex)
Tamoxifen is changed and broken down by the body. CBD might affect how quickly the body breaks down tamoxifen. This might affect levels of tamoxifen in the body.
Topiramate (Topamax)
Topiramate is changed and broken down by the body. CBD might decrease how quickly the body breaks down topiramate. This might increase levels of topiramate in the body by a small amount.
Valproate
Valproic acid can cause liver injury. Taking cannabidiol with valproic acid might increase the chance of liver injury. CBD and/or valproic acid might need to be stopped, or the dose might need to be reduced.
Warfarin
CBD might increase levels of warfarin, which can increase the risk for bleeding. CBD and/or warfarin might need to be stopped, or the dose might need to be reduced.
Zonisamide Zonisamide is changed and broken down by the body. CBD might decrease how quickly the body breaks down zonisamide. This might increase levels of zonisamide in the body by a small amount.
These interactions can vary in severity and may necessitate adjustments in dosage or careful monitoring by healthcare providers to avoid adverse effects.
Once again, always consult with your health care provider before taking any CBD product.
This content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any new supplement, including CBD, especially if you take prescription medications or have underlying health conditions. These statements have not been evaluated by the Food and Drug Administration. CBD products are not intended to diagnose, treat, cure, or prevent any disease.
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