A needle pulled out early, a pen stopped short, or the dose leaked: why you should not simply redose, and how to handle it. Not medical advice.
Key points
- 01First figure out how much actually went in. A partial dose can happen if the needle came out early, a pen did not finish its count, or the medicine leaked back out. How much was delivered is usually impossible to measure precisely, which shapes what you do next.
- 02Do not automatically give the rest. Topping up with a second injection risks a double dose, because you cannot know exactly how much the first attempt delivered. Guessing high is the more dangerous error, so do not simply redose to be safe.
- 03A pen that stalled is a specific case. If a pen stopped mid-injection it may be a mechanical or priming issue rather than an empty cartridge. Our pen-not-working and priming guides cover diagnosing a pen before you assume a missed dose.
- 04Leakage at the site usually loses very little. A small bead of medicine at the skin after withdrawal is common and typically a negligible amount. Our injection-leaking-out guide explains techniques that reduce it, and why it rarely justifies a top-up.
- 05Note the time and amount for your prescriber. Record what happened, roughly how much you think was delivered, and when. That information lets your prescriber or pharmacist advise on the next scheduled dose rather than you improvising.
- 06When in doubt, ask before redosing. For most weekly GLP-1 medicines the safest default is to wait and get advice rather than inject more the same day. Our missed-dose guide covers timing, but a partial dose is a good reason to call.
Frequently asked questions
I only injected part of my dose. Should I inject the rest?+
Not automatically. You cannot measure exactly how much went in, so topping up risks a double dose, which is the more dangerous error. Note what happened and ask your prescriber before redosing. Not medical advice.
My pen stopped partway through. What happened?+
It may be a priming or mechanical issue rather than an empty cartridge. See our pen-not-working and priming guides to diagnose the pen before assuming you missed the dose.
A drop of medicine leaked out. Did I lose my dose?+
Usually not. A small bead at the skin after withdrawal is common and typically negligible. Our injection-leaking-out guide covers techniques to reduce it and why it rarely warrants a top-up.
What should I tell my prescriber?+
Record what happened, roughly how much you think was delivered, and the time. That lets them advise on your next scheduled dose instead of you guessing at a correction.