How Often Do You Take a GLP-1? Weekly Dosing Explained (October 2026)

01 · The schedule

How often do you take a GLP-1?

Mounjaro is a once-weekly injectable prescription medicine made by Eli Lilly.¹ Wegovy is also once weekly. The pens are built around this rhythm: each Mounjaro KwikPen contains four weekly doses, so one pen lasts a month at a steady dose.¹

The table shows how the main injectable options differ.

The weekly GLP-1 shots guide covers the weekly rhythm in more depth.

02 · Is it for you?

Should I take a GLP-1, and who can?

Whether you should take a GLP-1 is a prescriber decision, not a self-diagnosis. Mounjaro is licensed in the UK for weight management in adults and for type 2 diabetes, and it is used alongside a reduced-calorie diet and increased physical activity.¹

On the NHS, Mounjaro is available, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

Private treatment still needs a consultation. Ours is free and reviewed by a GPhC-registered prescriber, and orders that turn out to be unsuitable are refunded automatically. If you are weighing it up, see our guide to whether you can take weight loss injections. When you are ready to see the options, the Mounjaro pen page shows live prices and the consultation, and our weight loss clinic page explains the wider service.

03 · Dose ladder explained

How much GLP-1 should I take? The dose ladder

How much you take depends on where you are on the ladder, and your prescriber decides that. Everyone starts Mounjaro on 2.5mg once a week. This starting dose is about letting your body adjust, not about weight loss itself.¹

After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals (7.5mg, 10mg, 12.5mg) up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹ Many people settle at a maintenance dose of 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber will guide the right pace.¹

The words "at least" and "minimum" matter. Four weeks is the earliest a step can happen, not a target. If you are still adjusting, or side effects are bothering you, a prescriber can hold you at a dose for longer.

Wegovy follows its own ladder of 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg, with a step after at least four weeks until the 2.4mg maintenance dose.¹⁸ The two ladders are not interchangeable, so never map one medicine's number onto the other.

For cost planning, the standard price of one Mounjaro pen is £169.99 at 2.5mg and £218.99 at 5mg. If you step up after 4 weeks on each of 2.5mg, 5mg, 7.5mg and 10mg, your first four pens (2.5mg to 10mg) total £959.96 at standard prices. A new customer's first order is £40 less, and every later order is £25 less.

04 · Same day, any time

Do I need to take it at the same time every week?

You need the same day each week, but not the same time. Mounjaro is injected under the skin (subcutaneously) once a week, on the same day each week, at any time of day, with or without food.¹

That also answers "when is the best time to take your GLP-1?" There is no "best" time of day. Mounjaro works the same morning or evening, with or without food. What matters is the same day each week.¹

Pick a day and time you will remember. Many people choose a weekend morning so early side effects fall on days off. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹³

Practical habits help more than any clever timing. Set a repeating phone reminder, tie the injection to something you already do on that day, and keep the pen where you will see it, with the cap on and stored as the storage guidance says. Our free GLPTrackr companion app can also help you track doses and your journey.

What if I miss a dose or want to change day?

If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on with your usual day.¹ If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day. Never take two doses within 3 days of each other.¹

You can change your weekly injection day if needed, as long as at least 3 days (72 hours) have passed since your last dose.¹ A common reason is a holiday, a work rota or wanting side effects to fall on a day off. Move the day once, deliberately, then settle into the new rhythm rather than drifting.

If you have missed several doses in a row, or are unsure which dose you should restart on, contact the prescribing team before injecting. Our support team is available Monday to Friday, 9am to 5pm, and ongoing monthly reviews are part of our aftercare.

05 · How to inject

How do you take a GLP-1 pen?

You inject it into the fatty layer under the skin, rotating the site each week. Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose.¹

The Mounjaro KwikPen is set by turning the dose knob until the dose indicator shows the correct dose in the window.

For the press-and-hold step and the needle handling, follow the pen's instructions in the patient information leaflet rather than a remembered technique from another device. Needles, a sharps bin and injection guidance are included with every order.

06 · Storage and travel

Storing pens between weekly doses

Keep Mounjaro pens in a fridge at 2–8°C and never freeze them.¹ Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, useful for short trips, after which it should be discarded. Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹

Unopened pens should be kept in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit; figures circulating online often come from other countries' labels.¹³

You can fly with Mounjaro. Carry pens in hand luggage (hold luggage can fall below freezing), ideally in a cool bag with the prescription label or a copy of your prescription.¹³ In-use pens tolerate up to 30 days not above 30°C, so most holidays need no special arrangements; for hot climates use an insulated pouch. Check destination rules for travelling with prescription injectables before you fly.

07 · Drops, pills and daily options

GLP-1 drops, oral liquids and pills: how often?

The licensed GLP-1 medicines are prescription-only and supplied after a consultation. Be wary of any site offering to supply without a consultation or prescription.

Licensed tablets do exist. Wegovy tablets and Foundayo have their own product information, and their schedule is set by that information, not by the weekly pen rhythm.²⁰²¹ Our guide to how to take GLP-1 pills goes through the practical side, and the Wegovy pen page shows the injectable option.

Liraglutide, sold as Saxenda and in other products, is supplied at 6mg per millilitre and is a daily injection, unlike once-weekly Mounjaro and Wegovy. If you are prescribed it, follow your prescriber's schedule exactly.

Whatever the form, never combine two GLP-1 medicines. Different brands are not top-ups for each other.

08 · No microdosing or stretching

Can I change how often or how much I take?

No.

Mounjaro is a once-weekly medicine, and your prescriber sets the dose and the pace of any increases. If the schedule feels too much, tell your prescriber. There are safe options within the licence, and they involve your care team rather than guesswork.

The same goes for taking doses closer together to "catch up". The missed-dose rule is the only catch-up rule: never take two doses within 3 days of each other.¹

09 · How long and what to expect

How long do you take a GLP-1 for weight loss?

Treatment is continuing, reviewed by your prescriber, rather than a fixed course. Weight loss on Mounjaro is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest; most measurable progress builds from 5mg onward, month by month.¹ Trials measured results at 72 weeks, so think in months, not days, and judge progress by trend, not individual weigh-ins.

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² These are trial averages, individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

The first weeks include water weight, so the trend over weeks matters more than any single weigh-in.¹³

Why am I not losing weight?

Slow early progress is common and often normal. Some people notice appetite change and early loss in the first week, others feel little until a higher dose; both are normal.¹³

Treatment response is reviewed by your prescriber: if you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.¹ Before then, check the basics: injecting on a steady day each week, following the dose ladder as advised, and pairing the medicine with a reduced-calorie diet and more activity.

For the longer-term picture, see how long you can stay on GLP-1 treatment. If you stop, tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹

10 · Shorthand searches

Quick answers on how often to take it

"How often should I take GLP-1?" For Mounjaro and Wegovy, once a week. "How often can I take it?" No more often than your prescriber has set, and never two doses within 3 days of each other. "When should I take it?" On the same day each week, at a time you will remember.

"How do you take a GLP-1?" The answer depends on the product; see how often people take a GLP-1. If you are comparing weekly and daily products, ask the prescriber at consultation which suits your routine, because a weekly schedule suits many people who dislike daily reminders.

Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full. Delivery is free next-day tracked, in temperature-controlled packaging, with same-day dispatch when ordered by 3pm. All six doses are in stock through official LillyDirect supply.

11 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹