Mounjaro 5mg Injection

Mounjaro (tirzepatide) is a dual GIP/GLP-1 receptor agonist that has been licensed by the MHRA in the UK for type 2 diabetes and is recommended by NICE for weight management¹.

The 5mg dose is typically the second step in the dose-titration pathway after initially starting on 2.5mg to assess tolerability. Many people progress to 5mg to enhance appetite suppression and weight loss effects.

The 5mg pen can be prescribed after you have safely tolerated the starter dose of 2.5mg for around 4 weeks, and your clinician assesses that you are ready to step up³.

The 5mg dose is introduced to boost the effect of the medication. At this dose many patients begin to notice stronger reductions in appetite and greater weight loss momentum.

Benefits you may notice

• Appetite reduction – a marked decline in hunger signals compared to 2.5mg.
• Progressive weight loss – many members see a further drop in weight when moving to 5mg, particularly if diet and activity are optimised.
• Metabolic gains – even if you don’t have type 2 diabetes, tirzepatide may improve glucose control, insulin sensitivity and reduce cardiovascular risk markers².

• Mild nausea or feeling queasy – often passes within a few weeks. Try eating smaller, more frequent meals and avoid very fatty or greasy food.
• Fatigue or mild tiredness – some people notice temporary low energy as their body adjusts.
• Digestive issues – bloating, constipation or stomach discomfort are possible. Try increasing fibre and fluid intake, and check with your clinician if side effects are persistent.

With the dose increased to 5mg, you may experience:

• Greater activation of GLP-1 and GIP pathways – this means stronger appetite suppression and slower gastric-emptying (you feel fuller longer).
• Improved insulin resistance – if you have pre-diabetes or type 2 diabetes, you may see measurable improvements in glucose control.
• Reduced hunger cues – you may feel less frequent hunger, which means you’ll need to actively monitor your eating pattern (don’t skip meals).

“Started 5mg 3 weeks ago. Have not had any side effects. Didn’t have any really on 2.5mg either. Some people seemed to have really bad side effects on 5mg. I read so many horrible stories that I was afraid to take it but I’ve been fine.”

“On my 2nd week of 5mg. I have to say that I’ve injected in my arm this week and I’m feeling more suppression than when I did my stomach last week. Don’t know if that’s just psychological..!!”

“I noticed a tailing off of effectiveness of the 2.5 in the third month but the 5 is going well, bar some nausea and tiredness the first couple of days after injection.”

“I took my first 5mg on Monday and have been absolutely fine, if anything I think it’s better because I’m less hungry.”

You may consider stepping up to Mounjaro 5mg if:

• You have been on 2.5mg for at least 4 weeks without significant side effects.
• You notice your appetite suppression on 2.5mg is beginning to fade before the next dose.
• Weight loss progress on 2.5mg has slowed or plateaued.
• You are not experiencing significant side effects that would limit your ability to progress.

You may need to hold or reduce your dose if:

• You are experiencing significant side effects at 7.5mg.
• You are losing weight too rapidly, which could bring nutritional or safety concerns.
• You have reached your target weight and plan to taper off Mounjaro or maintain at a lower dose.

• Don’t skip meals. You may feel less hunger, but skipping meals can lead to blood-sugar dips and worsen nausea.
• Don’t rush increasing the dose. Give your body time to adjust. Many people stay on 5mg for at least 4 weeks (or as your clinician advises).
• Don’t ignore side effects. If side effects feel unbearable, speak to your clinician. Temporary dose reduction or a pause in treatment may be appropriate.

¹ National Institute for Health and Care Excellence (NICE). Tirzepatide for managing overweight and obesity (Technology appraisal guidance TA1026). Published 23 Dec 2024. Last accessed November 2025. [https://www.nice.org.uk/guidance/ta1026/chapter/1-Recommendations]

² National Institute for Health and Care Excellence (NICE). Tirzepatide for managing overweight and obesity (TA1026). London: NICE; 23 December 2024. Last accessed November 2025. [https://www.ncbi.nlm.nih.gov/books/NBK611612/]

³ NHS England. Using tirzepatide (Mounjaro®) for weight management: clinician guidance. Published 2025. Last accessed November 2025. [https://www.england.nhs.uk/ourwork/prevention/obesity/medicines-for-obesity/weight-management-injections/]

Diabetes UK. Mounjaro (tirzepatide) – uses, how it works and side effects. Last accessed November 2025. [https://www.diabetes.org.uk/about-diabetes/looking-after-diabetes/treatments/tablets-and-medication/glp-1/mounjaro]

Wilding JPH et al. “Tirzepatide once weekly for the treatment of obesity.” New England Journal of Medicine. 2022; 387(18): 1713–1724. DOI: 10.1056/NEJMoa2206038. Last accessed November 2025. [https://www.nejm.org/doi/full/10.1056/NEJMoa2206038]

Eli Lilly and Company Ltd. “Mounjaro® KwikPen 5 mg solution for injection in pre-filled pen – Summary of Product Characteristics (SmPC).” Electronic Medicines Compendium (eMC). Last accessed November 2025. [https://www.medicines.org.uk/emc/product/15482/smpc]

This article is for general information only and should not be used for the diagnosis or treatment of medical conditions. Medic Spot Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. In the event of an emergency, please call 999 for immediate assistance.

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