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Can I take 150 and Delta--tetrahydrocannabinol together?

Drug interaction guide

Combining sertraline and delta-9-tetrahydrocannabinol (THC) can increase the risk of side effects from both substances. You may experience extreme drowsiness, dizziness, confusion, and difficulty concentrating. There is also an increased risk of 'serotonin syndrome' (a rare but serious condition caused by too much serotonin) and potential heart-related issues like a fast or irregular heartbeat. Additionally, cannabis can sometimes worsen the anxiety or depression that sertraline is being used to treat.

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Why this happens

Both sertraline and THC are processed by the same enzymes in the liver (specifically CYP2C9, CYP2C19, and CYP3A4). Because they are 'competing' for these enzymes, the levels of both substances in your blood can rise higher than expected. Furthermore, both drugs affect brain chemicals and the central nervous system, leading to an additive effect on your coordination and mental state.

You should use extreme caution and speak with your doctor before combining these substances. It is illegal to drive with any cannabis in your system in the UK, and the sedating effects of this combination make driving or operating machinery even more dangerous. If you experience a rapid heartbeat, severe shivering, or significant confusion, seek medical help immediately.

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Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

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Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
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