The direct answer: Mounjaro for diabetes is a weekly medicine added to your wider plan
Mounjaro is a brand name for the active substance tirzepatide, given as a weekly injection under the skin. The European Medicines Agency describes its use in type 2 diabetes that is not controlled well enough, alongside diet and exercise, on its own when metformin is unsuitable, or added to other diabetes medicines [1]. It is not a replacement for food habits or follow-up, and it is not simply a tool for anyone who wants to lose weight.
Two points matter most. First, the same substance is prescribed for two different aims, diabetes and weight, and the assessment and follow-up differ for each [1, 4, 5]. Second, adding Mounjaro for someone who already uses insulin or a sulfonylurea can raise the risk of low blood sugar, so the doctor reviews the existing doses [2, 4].
One fixed rule: do not stop, reduce or change any diabetes medicine on your own, even if your sugar has dropped. That decision belongs to your doctor after reviewing your readings and tests [4].
Mounjaro for diabetes versus for weight: same substance, different goal
The European agency separates two uses: type 2 diabetes, and weight management for adults with obesity or overweight and a related health problem, alongside a reduced-calorie diet and more activity [1]. In diabetes the main target is HbA1c control. In weight management the target is the amount of weight lost and improvement in related conditions.
The American Diabetes Association Standards of Care 2026 say weight management should be a primary treatment goal alongside glucose control, that medicines which help weight should be prioritised, and that tirzepatide and semaglutide have the highest efficacy for both glucose lowering and weight loss [4, 5].
The SURMOUNT-2 trial enrolled people with obesity or overweight and type 2 diabetes (HbA1c 7 to 10 percent). After 72 weeks, body weight fell by about 12.8 to 14.7 percent on tirzepatide versus 3.2 percent on placebo. The manufacturer funded the trial [12]. This is a result for a defined group under monitoring, not a promise for any individual. For more on this, see our guide on General Mounjaro guide.
What the trials showed for HbA1c
The SURPASS programme is a set of phase 3 trials in type 2 diabetes, all funded by Eli Lilly [7, 8, 11]. These figures are group averages, and your own result may differ.
In SURPASS-1 (tirzepatide alone for 40 weeks, starting HbA1c 7.9 percent) HbA1c fell by 1.87 to 2.07 points, versus a 0.04 rise on placebo [11]. SURPASS-2 compared it with semaglutide: HbA1c fell by 2.01 to 2.30 points versus 1.86, and weight loss was larger by 1.9 to 5.5 kg [7].
SURPASS-3 compared it with insulin degludec over 52 weeks: HbA1c fell by 1.93 to 2.37 points versus 1.34, and weight dropped on tirzepatide while it rose by about 2.3 kg on insulin [8]. In SURPASS-5 it was added for people already on insulin glargine, and HbA1c fell by 2.11 to 2.40 points versus 0.86 on placebo [10].
What this means: the medicine lowered glucose strongly in trials, but your doctor looks at your personal target, not at a trial number. For more on this, see our guide on HbA1c test: what the result means.
Which diabetes medicines can it be combined with?
The European agency states it can be taken alone when metformin is unsuitable, or added to other diabetes medicines [1]. In trials it was added for people on basal insulin [10], compared with insulin in people on metformin [8], and tested in people at high cardiovascular risk [9].
The American Standards say treatment plans that include insulin, some GLP-1 medicines and tirzepatide achieve the largest HbA1c reductions, while DPP-4 inhibitors achieve the smallest [4]. So the doctor decides which medicines stay and which are swapped; ask before adding or stopping anything.
Metformin itself needs its own follow-up, including vitamin B12, which has a separate article. Any change to metformin or another medicine happens after the doctor reviews your tests [4].
If you take other medicines or supplements (blood pressure, lipids, thyroid), bring the whole list to the visit, because the medicine review is part of the decision [4]. For more on this, see our guide on Metformin and vitamin B12.
Low blood sugar: when does the risk go up?
Mounjaro on its own is a modest cause of low blood sugar, but the picture changes when it is combined with a medicine that raises insulin release, or with insulin itself. The label warns about low blood sugar in people using it with an insulin-releasing medicine such as a sulfonylurea, and advises considering a lower dose of that medicine when starting [2]. The European agency lists low blood glucose as common when it is used with a sulfonylurea or insulin [1].
The American Standards say that when a new glucose-lowering medicine is started, the clinician should reassess the need for and dose of medicines with a higher hypoglycaemia risk [4]. That is why the review happens in clinic, not as your own decision.
Trials support the idea. In SURPASS-4 (52 weeks) low blood sugar occurred in 6 to 9 percent on tirzepatide versus 19 percent on insulin glargine, and among those not on a sulfonylurea 1 to 3 percent versus 16 percent [9]. In SURPASS-3 it was 1 to 2 percent versus 7 percent on insulin degludec [8].
What to do: keep a glucose meter at hand, log readings and tell the doctor about any low reading. Do not change an insulin dose or any other medicine yourself.
Side effects and warning signs
The most frequent effects recorded in trials were gastrointestinal: nausea, diarrhoea, vomiting and reduced appetite, mostly mild to moderate [7, 8, 11]. In SURPASS-2, for example, nausea was 17 to 22 percent and diarrhoea 13 to 16 percent [7]. MedlinePlus also lists constipation and indigestion [3].
Some signs should not wait for an appointment: severe, persistent abdominal pain may mean pancreatitis, and the label says to stop the medicine if it is suspected [2, 3]. Severe vomiting or diarrhoea can cause dehydration, and the label advises monitoring kidney function in that situation [2]. Tell your doctor about any eye problem, because rapid improvement in glucose control can temporarily worsen diabetic retinopathy and it needs monitoring [2].
The medicine is contraindicated with a personal or family history of medullary thyroid carcinoma (MTC) or serious hypersensitivity to it [2], and MedlinePlus also names MEN2 [3]. It may reduce the effectiveness of hormonal birth control [3].
For details, see the dedicated red-flags article. For more on this, see our guide on Serious side effects and red flags.
HbA1c and kidney follow-up
HbA1c reflects average glucose over roughly three months, and for most people the goal is below 7 percent, but the doctor may set a different target for you. Ask how often you should be tested [6].
The American Standards say the treatment plan should be reviewed at regular intervals, for example every 3 to 6 months, and that changes should not be delayed when the goal is not met [4]. When a medicine is used for weight management, the Standards call for assessing effectiveness and safety at least monthly for the first 3 months and at least quarterly after that [5].
On the kidneys: the American Standards say that in type 2 diabetes with chronic kidney disease, an SGLT2 inhibitor or a GLP-1 medicine with proven benefit in that group should be used [4]. The Mounjaro label advises monitoring kidney function if vomiting, diarrhoea or dehydration occurs [2]. In practice, any kidney result in your tests needs to be read by the doctor together with the treatment decision, and you should report dehydration.
In Maadi the doctor reviews your readings and previous tests with you, so bring them to the visit. For more on this, see our guide on Diabetes doctor in Maadi.
What to prepare before the visit
The visit is more useful if you bring: the names and doses of all diabetes medicines and insulin, your latest HbA1c and kidney tests, a log of glucose readings including any low reading, and any digestive or vision symptoms. The review rests on the doctor knowing which medicines carry a low-sugar risk before anything is added [2, 4].
Also mention any history of pancreatitis, a family history of thyroid cancer or an eye problem, because the label and MedlinePlus list these [2, 3]. The visit does not guarantee a prescription; a medicine is prescribed only when suitable after reviewing the history and tests [4].
If the doctor finds Mounjaro suitable, they will explain use and follow-up. If adjusting food and current medicines is enough for now, they will say so, because this is a medical decision, not a sales one.
Seeing Dr Mohab Ashraf at the Maadi branch
Dr Mohab Ashraf Fouad is a specialist in internal medicine and diabetes and sees patients at La Rose Maadi on Saturday only. The address is 14 El-Mokhtar Street, off El-Nasr Street, behind QNB Bank, New Maadi, Cairo. Branch hours are 2 to 8 pm and times vary by doctor, so confirm the day and hour when booking. To book, call or message on WhatsApp at 010 4066 1893.
This article was reviewed with Dr Shimaa Fouad. It is for education and does not replace your own doctor's visit, and any change to diabetes medicines happens after examination and tests [4, 2]. When you are ready: Book your appointment.
