Can I take Cyproheptadine and Dexmethason together?
Drug interaction guide
Originally published 14 Mar 2026
Meets Patient’s editorial guidelines
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Taking cyproheptadine and dexamethasone together may increase the risk of certain side effects, particularly those affecting your metabolism and stomach. Cyproheptadine can sometimes interfere with how well steroids like dexamethasone work, or it may increase the risk of weight gain and increased appetite, which are side effects common to both medications. There is also a small risk that combining these could increase the chance of developing stomach irritation or ulcers.
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Why this happens
Cyproheptadine is an antihistamine that also has anti-serotonin properties, which can stimulate appetite. Dexamethasone is a potent corticosteroid that also affects metabolism and appetite. When used together, their effects on weight gain and blood sugar can be additive. Additionally, some studies suggest cyproheptadine might slightly reduce the effectiveness of dexamethasone in certain hormonal tests, though the clinical impact on daily treatment is usually small.
What you should do
Back to contentsYou can usually take these medicines together, but you should be mindful of side effects. Monitor your weight and appetite closely. If you have a history of stomach ulcers or if you notice any new stomach pain, indigestion, or black stools, contact your doctor. If you are taking dexamethasone for a specific hormonal condition (like Cushing's syndrome), ensure your doctor knows you are also using cyproheptadine.
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Important precautions
Back to contentsGlaucoma and Urinary Retention
Do not take this medicine if you have narrow-angle glaucoma or difficulty passing urine (such as from an enlarged prostate), as it can severely worsen these conditions.
Food and drink warnings
Back to contentsAlcohol
Avoid drinking alcohol while taking cyproheptadine. This medicine causes drowsiness, and alcohol will significantly increase this effect, making you feel much sleepier and increasing the risk of accidents.
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Using other medicines
Back to contentsTaking 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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