Medicine dosage – how to take a dose safely
How to read a tablet, capsule or liquid medicine label, avoid double dosing and know when a pharmacist should confirm the instructions.
Dose, strength, frequency and duration
A medicine dose is the amount taken at one time. Strength is how much active ingredient is in each tablet, capsule, spoonful or measured volume. Frequency is how often it is taken, and duration is how many days or weeks it is used. All four matter.
Two products can look similar while having different strengths, and two medicines can have different names while sharing an ingredient. Never copy an adult's dose, a child's dose or somebody else's prescription.
How to check a medicine dose
- Read the active ingredient and strength on the label, not only the product name.
- Check that the formulation is the one you were told to use — tablet, capsule, liquid, inhaler or another form.
- Use the measuring device supplied for a liquid. Do not use a kitchen spoon unless a health professional has told you how to measure it.
- Check the age, weight, pregnancy and medical-condition warnings on the label or leaflet.
- Write down when you took a dose if you are tired, unwell or caring for someone else. This prevents an accidental repeat dose.
Avoid doubling the same ingredient
Combination cold, flu and pain products may contain the same active ingredient as a single-ingredient medicine. For example, paracetamol can be present in more than one product. Taking both without checking the labels can turn an ordinary day of treatment into an overdose.
A generic and a brand are not automatically different medicines. Compare the active ingredient and strength before adding one box to another, and ask the pharmacist if you cannot tell.
If the dose is unclear or too much was taken
- Do not double the next dose to compensate. Check the leaflet or ask a pharmacist what to do, because missed-dose advice differs by medicine.
- Keep the package, leaflet and any remaining medicine so a pharmacist or poison centre can identify it.
- Get urgent help for sleepiness, confusion, breathing difficulty, seizures, collapse, severe vomiting or any suspected overdose — even if the person initially feels well.
- Do not induce vomiting and do not give milk, salt water or another home remedy unless a health professional tells you to.
Common questions
- How do I know what dosage to take?
- Use the exact instructions on your prescription, label or leaflet. If the strength, timing or duration is unclear, ask a pharmacist rather than using a general internet answer, because the correct dose depends on the medicine and the person taking it.
- Can an adult use a child's dosage?
- Do not assume so. Children may need a weight-based dose, a different formulation or a different medicine, and some adult products are unsafe for them. Ask a pharmacist or clinician using the child's age and weight.
- What should I do if I took too much medicine?
- Call the Poisons Information Helpline or emergency services immediately, keep the packet or bottle with you, and do not induce vomiting. Some overdoses cause serious harm before symptoms appear.
Sources
- Primary Healthcare Standard Treatment Guidelines and Essential Medicines List, 8th editionNational Department of Health, South Africa
- Medicines Online Directory and patient information leafletsSouth African Health Products Regulatory Authority
Last reviewed 11 August 2026.