When to reorder your Mounjaro pen so you never run out
Short answer: count backwards from your last remaining dose. A UK KwikPen holds 4 weekly doses, so the safe habit is to start your reorder when you take the second-to-last dose, giving the pharmacy a full week plus buffer. If your supplier has had stock delays, or a prescriber review is due before the next pen, start earlier still. The hard part is not the arithmetic; it is remembering to do it on the right week.
Know your real lead time
Reordering is not one step, it is a chain: your request, a prescriber or pharmacist check (and sometimes an ID or weight review for private online pharmacies), dispensing, then cold-chain delivery. Each link adds days, and any of them can stall. Add the known variables:
- Stock availability. GLP-1 supply has had rough patches; a strength can be out for days or weeks at short notice.
- Reviews that gate the reorder. Many private services require a check-in before issuing the next month, and titration changes can mean a different strength needs prescribing.
- Weekends and bank holidays. A Thursday reorder and a Friday reorder can arrive in different weeks.
- Storage limits. Pens live in the fridge, and an in-use pen has a limited room-temperature life, so hoarding months of stock is not the answer either.
A simple reorder rule
- Each jab day, know how many doses remain in the pen or box
- When you take the second-to-last dose, place the reorder that day
- If your last order was delayed, or a review is due, move the trigger one dose earlier
If a gap does happen despite everything, do not double up to catch up; ask your prescriber or pharmacist how to restart, since their advice can depend on how long the gap was.
How PepLevel handles it
Because every dose is logged, PepLevel always knows how many doses are left in your pen or vial and when, at your schedule, you will run out. The supply view shows what is left and the expiry date at a glance, and a reorder reminder arrives ahead of your run-out date, 14 days by default, adjustable to the lead time you actually experience. No spreadsheet, no counting pens in the fridge door.
Know before you run out
Doses left, expiry and a reorder nudge timed to your schedule. Coming soon to the App Store.
Get PepLevelMedical disclaimer: this guide is general information about planning reorders and keeping records, not medical advice. Questions about missed doses, restarting after a gap, storage or supply belong with your prescriber or pharmacist. PepLevel is a logging and reminder tool only.