Domperidone: what it does and what to watch for

Domperidone is a medication that speeds up stomach emptying and helps with nausea and vomiting. It's also used off-label to boost lactation because it raises prolactin. Before you take it know this: domperidone can affect the heart rhythm in some people, so it isn't harmless.

How domperidone is used and dosed

Adults usually take 10 mg three times a day, 15–30 minutes before meals. Many guidelines limit total daily dose to 30 mg. Some doctors prescribe lower doses for breastfeeding support, often 10 mg twice a day, but you should follow your prescriber's plan. Do not exceed recommended dosing and avoid long-term use without medical review. For children and older adults dosing must be adjusted by a clinician.

Safety, side effects, and interactions

Common side effects include dry mouth, abdominal cramps, diarrhea, and raised prolactin which can cause breast tenderness or milk production. Less common but serious risks are QT prolongation and irregular heartbeat. That risk rises if you have existing heart disease, low potassium or magnesium, or if you take other drugs that prolong the QT interval.

Drugs that increase domperidone levels or add heart risk include strong CYP3A4 inhibitors (like ketoconazole, itraconazole), some macrolide antibiotics (erythromycin, clarithromycin), and certain antipsychotics and antidepressants. Tell your prescriber about every medicine and supplement you take. Your doctor may order an ECG or blood tests before starting treatment if you have risk factors.

Practical tips before you start: never buy domperidone from an unknown online seller without a prescription. Many countries require a prescription for safety reasons. Ask your clinician about an ECG if you have any heart symptoms, a history of arrhythmia, or take other QT-risk drugs. If you're breastfeeding and considering domperidone to increase milk supply, use the lowest effective dose and discuss breastfeeding alternatives and safety for your baby.

When to stop and call your doctor: stop domperidone and seek urgent care if you feel faint, have irregular heartbeats, severe chest pain, or sudden shortness of breath. Also report unexpected breast milk production or significant mood changes.

If you're pregnant, doctors usually avoid domperidone unless benefits clearly outweigh risks. Research on pregnancy is limited, so ask your obstetrician for safer options. For nausea related to gastroparesis or chemotherapy, your healthcare team may prefer other antiemetics that fit your heart profile. Always review alternatives like metoclopramide, ondansetron, or dietary changes with your provider. Finally, keep a simple log of symptoms when starting domperidone—note dosing times, any palpitations, dizziness, or new breast changes. That record helps your clinician spot problems early and decide whether to continue, adjust dose, or switch treatment.

Questions? Talk to your pharmacist or doctor. If buying online, use only licensed pharmacies and never skip medical checks. Keep records and ask for an ECG if you're unsure.