If you have missed a dose, look first at the leaflet that came with the medicine. Leaflets usually have a section for this, headed something like "If you forget to take" or "What should I do if I forget a dose?", and what it says for your medicine comes before any general rule. Whatever the medicine, do not take a double dose to make up for the one you missed unless your prescriber has told you to.
If you cannot find the leaflet or it is unclear, ask a pharmacist. It is a quick question for them, and they can look up your exact medicine.
The general guidance, and its limits
The NHS Specialist Pharmacy Service (SPS) publishes general advice for pharmacists and other health professionals on what to tell someone who has missed a dose. It is meant for when the medicine's own information, such as its leaflet, does not cover the question. This is what it says:
| Situation | What SPS says, for most medicines |
|---|---|
| Up to 2 hours late | Taking the dose up to 2 hours late is acceptable |
| More than 2 hours late, medicine taken once or twice a day | Take the missed dose as soon as you remember, as long as the next dose is not due within a few hours |
| More than 2 hours late, medicine taken more than twice a day | Skip the missed dose and take the next one at the usual time |
| Any medicine | Never take a double dose to make up for a forgotten dose, unless a prescriber has advised it |
MedlinePlus, the US National Library of Medicine's consumer site, gives similar advice on its drug pages. Its aspirin page, for one, says to take the missed dose as soon as you remember, to skip it if it is almost time for the next dose, and not to take a double dose to make up for a missed one.
Your medicine's leaflet may say something different, and when it does, follow the leaflet. Some medicines have their own rules because timing matters more for them.
Medicines where the general rule does not apply
SPS lists medicines that need their own missed-dose advice, and says the list is not exhaustive:
- antiseizure (epilepsy) medicines
- the contraceptive pill
- medicines for Parkinson's disease, where SPS says even a delay of 30 minutes could be serious
- insulin
- methotrexate taken once a week
- warfarin
- immunosuppressants and cancer medicines
For these, follow the leaflet and what the team that prescribed the medicine told you, and contact them if you are not sure what to do.
Two calculators on this site work through a specific missed-dose rule for you. The missed birth control pill calculator uses the CDC steps for your type of pill. The GLP-1 medicines Mounjaro, Zepbound, Wegovy and Foundayo are not on the SPS list, but each FDA label has its own missed-dose rule, and the GLP-1 dose schedule calculator checks a missed dose against it.
Knowing whether you took it
Some missed-dose questions are really about not knowing whether the dose went in at all. A log answers that before you have to call anyone. Doz is a free download on the App Store: it reminds you at each dose time, and each dose you log shows as taken on the day's list, saved with the time you logged it, so "did I take it this morning?" has an answer. If you dismiss a reminder without logging the dose, Doz can send one follow-up nudge. It does not tell you what to do about a missed dose. That is still for the leaflet and your pharmacist.
When to call a pharmacist
Call a pharmacist, or the team that prescribed the medicine, when:
- the leaflet does not say what to do, or you cannot find it
- the medicine is on the list above
- you have missed more than one dose
- you are not sure whether you took the dose at all
If you cannot remember whether you took it, do not take another "just in case". Ask first.
For why doses get missed in the first place, and what helps, see why people miss medication doses.
Frequently Asked Questions
What should I do if I miss a dose of my medicine?
Check the missed-dose section of the leaflet that came with it, and follow that. If there is no leaflet or it is unclear, ask a pharmacist. For most medicines, the NHS Specialist Pharmacy Service's general advice is to take a once- or twice-daily dose when you remember unless the next one is due within a few hours, and to skip a missed dose of a medicine taken more than twice a day.
Should I take a double dose if I missed one?
No, unless your prescriber has told you to. The NHS Specialist Pharmacy Service and MedlinePlus both say not to take a double dose to make up for a missed one.
How late can I take a missed dose?
For most medicines, SPS says taking a dose up to 2 hours late is acceptable. Some medicines are different: SPS says that for Parkinson's medicines even a delay of 30 minutes could be serious. Check the leaflet for your medicine.
What if I can't remember whether I took my dose?
Do not take another one to be safe. Ask a pharmacist what to do for your medicine, and consider keeping a log of each dose so you can check next time.
Sources
- NHS Specialist Pharmacy Service: Advising on missed or delayed doses of medicines (updated 4 March 2025)
- MedlinePlus: Aspirin, "What should I do if I forget a dose?" (example of the standard wording)
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