A side effects checker is a lookup tool: you enter a medicine or a symptom and it shows what has been reported. It is useful for orientation and preparation. It cannot tell you whether your medicine caused your symptom, because that depends on your history, your other medicines and the timing, none of which a lookup can see.
Use the indexes below to check a medicine or a symptom, then take what you find to a pharmacist rather than acting on it alone. See also the South African checker guide.
Start here: find the right side-effect guide
Category cards
- Check by medicine. Medicine side effects A to Z
- Check by symptom. Side effect symptoms index
- Check a combination. Supplement and medicine interactions, over-the-counter interactions
- Check severity. Serious medication side effects
Common vs serious effects
A checker will list dozens of possible effects for almost any medicine, ordered by how often they were reported rather than by how much they matter. That ordering is the main way checkers mislead people. Read the serious list first, then the common list, not the other way round.
Common side effects vs serious side effects
Common examples linked to side effects checker
Effects that appear on almost every medicine listing, and which are usually mild and settle: nausea, headache, drowsiness, dizziness, dry mouth, loose stools or constipation, and tiredness. Because they appear everywhere, finding them on a checker tells you very little about your specific medicine.
Effects worth stopping on when you see them listed: liver or kidney warnings, blood disorders, severe skin reactions, cardiac rhythm effects, and mood or behaviour changes. These are the entries a pharmacist will want to discuss.
How to describe frequency without overclaiming
Checkers draw on reported effects. A report records that something happened while someone was taking a medicine, not that the medicine caused it. Volume of reports also reflects how widely a medicine is used and how much attention it gets, so a long list is not evidence that a medicine is dangerous.
Medicine, supplement and symptom categories covered
Priority related pages
- How to know if a medicine is causing your symptoms
- How to read the side effects section of a leaflet
- Supplement interactions checker
- Side effect or allergic reaction
How to choose the right next guide
If you take more than one product, check interactions rather than individual side effects. Most surprising symptoms in people on several medicines come from the combination, and a single-medicine lookup will miss that entirely.
When to speak to a doctor or pharmacist
Red-flag symptoms
Do not use a checker if any of these are present. Get emergency help:
- Difficulty breathing, wheeze, or a tightening throat
- Swelling of the face, lips, tongue or throat
- Chest pain, fainting or collapse
- Seizure, or sudden confusion or unresponsiveness
- A rash that blisters or peels, or sores in the mouth or eyes with fever
- Vomiting blood, or black tarry stools
- Thoughts of harming yourself
When to contact a doctor, pharmacist, or emergency service
A pharmacist has access to full product information and can see your other medicines. That combination is what a checker lacks, and it is why a two-minute conversation at a pharmacy counter usually beats an hour of searching.
How side effects can be reported in South Africa
What information to record
Product name, strength and batch number, the date the medicine started, the date the symptom began, and everything else you take including supplements.
Where reporting fits into medicine safety
The data a checker displays exists because people submitted reports. Adding yours improves what the next person finds. See reporting side effects in South Africa.
Most useful next pages
Priority related pages
How to choose the right next guide
Use a checker to prepare a question, not to answer one. The output is most valuable when you take it with you rather than act on it at home.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.