When to reorder Mounjaro: getting your timing right

Why the three-week mark is the practical trigger

Mounjaro is injected once a week, and each pen covers four injections. That puts your 'last dose' on roughly day 28. If you wait until you've taken your final dose before thinking about the next order, you're already behind, delivery, even when it's swift, takes a working day, and the clinical review adds a step before dispatch.

Ordering at the start of week three gives your prescriber time to review the repeat request, and means the pen arrives well before your next injection is due. If you order before midday on a weekday and your repeat is clinically approved, same-day dispatch is standard; your pen arrives the next working day via tracked DPD. Build that into your mental calendar and the timing becomes predictable.

One practical note: a lot of people find it easiest to tie reorders to a fixed point in their week, the same day they inject, for instance, or the Monday after their third dose. If you're unsure about when to take your Mounjaro injection, that's worth reading before you settle on a routine. Payday timing, bank holidays and pre-holiday planning are all worth thinking about in advance, because a Friday order heading into a bank holiday weekend won't arrive until Tuesday at the earliest.

What changes when a dose increase is coming

If your prescriber is moving you to a higher strength (from 5mg to 7.5mg, say) the reorder process is slightly different. At nume, dose increases are not automatic; your prescriber will want to see evidence that your current dose is well tolerated and that the increase is appropriate. This means the clinical review before a dose-change repeat can take a little longer than a straightforward like-for-like order.

Plan for that. If you know a dose increase is due at your next supply, flag it when you reorder rather than assuming it will be upgraded silently. The licensed treatment schedule for tirzepatide runs from 2.5mg up to 15mg in 2.5mg steps, with titration typically every four weeks, but the pace is always set by your prescriber, not by a calendar. Ordering the week before you run out, rather than the week you run out, gives that review room to happen without a gap in your supply.

Gaps in dosing: what the evidence says and what to do

Missing a dose occasionally is not catastrophic, but a multi-week gap matters more. The NHS tirzepatide guidance advises that if you miss a dose and your next scheduled injection is more than four days away, you can take it as soon as you remember, but if it's within four days of your next dose, skip it and continue from there. For longer gaps, the right course is always to check with your prescriber rather than to restart at the same dose without guidance.

That's another reason reordering in good time is worth the small effort. Running dry for a week is different from missing a single injection, and your prescriber's advice may differ accordingly. If you're unsure how a gap affects your treatment plan, the frequently asked questions section covers common scenarios, and our clinical team is available seven days a week for aftercare queries.

There's also a cost dimension worth acknowledging. Understanding how Mounjaro treatment is priced at each stage helps you plan orders without feeling rushed into spending more than you need to at once. One pen at a time is a perfectly reasonable approach for most people.

When to rethink whether to continue at all

Reordering is also a natural moment to pause and ask a broader question: is treatment still right for you right now? If you're several months in, it's worth knowing that NICE guidance (as detailed in the TA1026 appraisal of tirzepatide) recommends reviewing whether to continue if weight loss has been less than five percent after six months at the highest tolerated dose. That's a clinical conversation, not an automatic stop, but it's one worth having.

Equally, if side effects have been troublesome, or if your circumstances have changed, a reorder is a good prompt to raise those things. The question of when to stop Mounjaro is a genuinely useful one to think through before placing the next order rather than after. And if you're weighing up whether Mounjaro is the right choice for you, our guide walks through the factors a prescriber will consider alongside our broader decision guide on starting treatment. Our clinical team is there to help you think through any of this, not just to process orders.