Question 1

Can Mounjaro cause diarrhoea?

Accepted Answer

Yes, diarrhoea is one of the most common side effects of GLP-1 medication, along with nausea, vomiting and constipation. In the trials behind the US label for semaglutide 2.4 mg, 30% of adults reported diarrhoea against 16% on placebo (prescribing information), and the figure for tirzepatide (sold as Mounjaro) is up to 23% (prescribing information). The tirzepatide label states that the majority of nausea, vomiting and diarrhoea events occurred during dose escalation and decreased over time (prescribing information). Diarrhoea that does not go away should be reported to a doctor right away, because fluid loss can cause kidney problems (Medication Guides).

Question 2

Does Mounjaro make you tired?

Accepted Answer

It can. Fatigue is a listed adverse reaction in the US prescribing information for both semaglutide and tirzepatide (sold as Mounjaro): it was reported by 11% of patients on semaglutide 2.4 mg against 5% on placebo, and by 5 to 7% on tirzepatide, depending on dose, against 3% (prescribing information). Tiredness that comes with vomiting or diarrhoea that does not settle should be checked by a doctor, because of the dehydration and kidney risk the US Medication Guides describe (Medication Guides).

Question 3

Do Mounjaro injections hurt?

Accepted Answer

The trials recorded how often people had a reaction at the injection site, not what the injection feels like, so nobody can honestly tell you what it feels like. In the weight-management trials, 1.4% of people taking semaglutide reported an injection-site reaction against 1% of people injecting placebo (label). The tirzepatide label groups the term more broadly, adding bruising, pain and rash, and its injection-site reactions sit among the reactions reported in 5% or more of patients, so the two figures should not be read against each other (label). A brief sting, a small bead of blood or a faint mark that fades within the day are the things people ask about most, and the least likely to matter. If needles worry you, say so at your consultation, because it can shape how the first dose is approached.

Question 4

Does GLP-1 cause cancer?

Accepted Answer

The cancer the labels raise is thyroid cancer, and that warning comes from rodents: the US labels record thyroid C-cell tumours in rodents and state that the human relevance has not been determined (semaglutide, tirzepatide). In people the research disagrees, with a French case-control study finding a raised relative risk while a three-country Scandinavian cohort and a claims cohort of 460,032 users found none, so the question is open rather than answered (Bezin 2023; Pasternak 2024; Diabetes Care 2025). For pancreatic cancer, 113 randomised trials in adults with type 2 diabetes found no significant increase (odds ratio 0.94, 95% CI 0.52 to 1.70) (Monami 2017). These are the two cancers our pages cover: the semaglutide and tirzepatide labels rule them out for anyone with a personal or family history of medullary thyroid carcinoma or MEN 2, and any other cancer question is one for your doctor.

Question 5

Do GLP-1 medications protect the heart?

Accepted Answer

In one specific population, yes. In 17,604 adults aged 45 or over with overweight or obesity and established cardiovascular disease but without diabetes, semaglutide reduced cardiovascular death, heart attack or stroke by 20% versus placebo (Lincoff 2023). Everyone enrolled already had cardiovascular disease, so this does not describe a general weight-management population. Individual results vary.

Question 6

Is tirzepatide a GLP-1?

Accepted Answer

Yes. Tirzepatide (sold as Mounjaro) acts at the GLP-1 receptor, like the rest of the class, and also at the GIP receptor, which is why it is called a dual agonist (prescribing information). GLP-1 and GIP are both gut hormones released when you eat, and both feed into the systems that govern appetite and blood sugar. Semaglutide acts at the GLP-1 receptor.

Question 7

Is Wegovy the same as Ozempic?

Accepted Answer

They are the same molecule, semaglutide, in different products. Semaglutide 2.4 mg (sold as Wegovy) is registered in Singapore as an injection for weight management (HSA register), and the same molecule at lower doses (sold as Ozempic) is registered here for type 2 diabetes only (NDF). Which medicine suits a particular person, if any does, is decided by the doctor who assesses them.

Question 8

Is Ozempic available in Singapore?

Accepted Answer

Yes, for type 2 diabetes only. The lower-dose semaglutide injection (sold as Ozempic) is registered in Singapore for type 2 diabetes and has no registered weight-management indication here (NDF), so prescribing it for weight is off-label: a decision only a doctor who has assessed you can make, and one they may decide against. GLP-1 medicines here may be dispensed only by a registered doctor or a licensed retail pharmacy, against a valid prescription (MOH 2024). The semaglutide product registered for weight management is the 2.4 mg injection (sold as Wegovy) (HSA register).

Question 9

Is there a Mounjaro pill?

Accepted Answer

Not in Singapore: the tirzepatide products registered here are injections, as pens and vials (HSA register). The only GLP-1 tablet on Singapore's register is oral semaglutide (sold as Rybelsus), and its registered indication is type 2 diabetes, with no weight-management indication (Singapore NDF). A different tablet, Eli Lilly's orforglipron (sold as Foundayo), is approved in the United States and the United Kingdom but is not registered in Singapore, so no doctor here can prescribe it (HSA register; MHRA). Retatrutide and orforglipron are not registered in Singapore, and GetLean does not prescribe or supply them. GetLean does prescribe and supply HSA-registered GLP-1 medications, after a consultation with Dr Quek.

Question 10

How often to take Mounjaro?

Accepted Answer

The weekly injections, tirzepatide (sold as Mounjaro) and semaglutide, are taken once a week, at any time of day, with or without meals (semaglutide label; tirzepatide label). The semaglutide label adds that it is taken on the same day each week and that the time of day and the injection site can be changed without changing the dose (label); the tirzepatide label allows the dose day to move as long as at least 3 days (72 hours) separate two doses (label). A semaglutide tablet is taken once a day instead of once a week, but how a tablet is taken belongs on its prescription and leaflet, not on a web page. The doses, and the interval between each step up, come from your prescriber and your leaflet, not from an article. That is the label. Under the GetLean GLP-1 Taper Plan, set with Dr Quek, instead of one injection every 7 days, you might inject every 8, 9 or 10 days, and once you are on the lowest dose (Mounjaro 2.5 mg), injections can move to once every two weeks (GLP-1 microdosing at GetLean, step by step). On higher doses (7.5, 10 or 15 mg), if you go more than 10 days without an injection, the taper restarts on a lower dose. Taking a high dose after a long break can cause stomach and gut side effects, including pancreatitis. Speak to us before your next dose.

Question 11

What is GLP-1 microdosing?

Accepted Answer

There is no single agreed definition of microdosing. At GetLean, microdosing means taking the medicine below its labelled dose or schedule, as part of the GetLean GLP-1 Taper Plan for coming off. The GetLean GLP-1 Taper Plan gets you there in two ways, and often uses both: lower doses, where you come down to the dose you were on before, and longer gaps between injections, where instead of one injection every 7 days, you might inject every 8, 9 or 10 days. The two can be combined: for example, going from Mounjaro 15 mg once a week to 10 mg every 10 days. On higher doses (7.5, 10 or 15 mg), if you go more than 10 days without an injection, the taper restarts on a lower dose. Taking a high dose after a long break can cause stomach and gut side effects, including pancreatitis. Speak to us before your next dose.

Question 12

Does tirzepatide expire?

Accepted Answer

Yes. Tirzepatide is kept in the fridge at 2°C to 8°C before first use, and an unopened multi-dose pen kept refrigerated can be used until its printed expiry date (label). Once a pen or vial is out of the fridge or in use, the US labels set a shorter limit: up to 21 days in total at no more than 30°C for a single-dose pen or vial (label), and for a multi-dose pen or vial whichever comes first of 30 days at room temperature, 30 days after first use or the fourth weekly dose, discarded even with medicine left in it (label). The limits differ between pens, between medicines and between the US and European labels, so the leaflet in your own box is the one that applies to your pen.

Question 13

Can I drink coffee on Mounjaro?

Accepted Answer

For the weekly injections there is no coffee rule to quote, for or against: the US prescribing information for semaglutide 2.4 mg and tirzepatide (sold as Mounjaro) and the European product information for both do not mention coffee or caffeine (US semaglutide label; US tirzepatide label; EU tirzepatide SmPC; EU semaglutide SmPC). The semaglutide tablet is different: its label says to take it with a little plain water and then wait at least 30 minutes before eating or drinking anything, coffee included (US label). A PubMed search of titles and abstracts also finds no study built to test coffee or caffeine in people taking these medicines (PubMed search, 12 October 2026). What can be sourced is what is in the cup: Singapore's Health Promotion Board records a regular 250 ml kopi at 193 kcal and 19.05 g of sugar, and kopi O kosong at 33 kcal and none (HPB). Whether coffee suits you while on treatment is a question for your doctor.

Question 14

What to eat on Mounjaro?

Accepted Answer

Guidance during active weight loss is roughly 1.2 to 1.6 g of protein per kilogram of body weight a day (Leidy 2015), and a suppressed appetite makes that harder to reach because the thing that runs out first is stomach capacity, not calories. In Singapore that points to dishes where the protein is easy to pick out and finish first, such as sliced fish soup, steamed or roasted chicken rice, yong tau foo and fishball noodle soup, and to asking for less rice rather than less meat. The usual nausea tips, such as smaller meals and bland food, have not been tested in people taking GLP-1 medication, so treat them as low-risk things to try rather than evidence-based advice. This is general information, not a meal plan, and your doctor can say what suits you.

Question 15

What should I eat at a hawker centre when I'm on GLP-1 medication?

Accepted Answer

Order a dish where the protein is a separate object, such as sliced fish soup, steamed or roasted chicken rice, yong tau foo or fishball noodle soup, and eat the protein first. At the economy rice stall, HPB's database records two meats at 53.7 g of protein and 768 kcal against one vegetable and one meat at 34.51 g and 697 kcal, both recipe-derived values rather than measurements (HPB). Ask for less rice, not less meat, and split a large portion across two sittings rather than skipping the rest. At a shared zi char table, one more protein dish and one fewer fried starch on the order sheet changes what everyone eats.

Question 16

Can I claim Mounjaro on MediSave or insurance?

Accepted Answer

Not as a condition in its own right: as checked on 7 October 2026, obesity is not one of the 23 chronic conditions covered by MediSave's outpatient scheme (MOH). No GLP-1 medicine for weight is on MOH's list of subsidised drugs or the Healthier SG medication list (MOH; Healthier SG list), and the two Integrated Shield Plan wordings checked exclude treatment for obesity and weight reduction (Singlife; Prudential). MOH's rulebook for covered conditions such as diabetes lists weight-loss medication as claimable if clinically indicated and also as not claimable, and it does not say whether a GLP-1 medicine for weight counts (CDMP Handbook). Other insurers have their own wording, so the exclusions section of your own policy is the place to check.

Question 17

Can I switch doctors if I am already on Mounjaro?

Accepted Answer

Yes, with a new assessment: a new doctor in Singapore does not take over an existing GLP-1 prescription, they assess you and, where appropriate, write their own (Therapeutic Products Regulations). Being on treatment with another doctor does not change that a first-time patient of a telemedicine clinic is seen by real-time video (OMS Regulations). It helps to bring the name and dose of what you take now, any recent records, the other medicines and supplements you use, and an account of your treatment so far; patients have a right to their medical information, which a doctor makes available on request (SMC). At GetLean nothing is prescribed or dispensed before Dr Quek has assessed you, and a consultation does not guarantee that a prescription will be issued.

Question 18

Can GLP-1 cause depression?

Accepted Answer

In pooled analyses of the large trials of semaglutide 2.4 mg and of tirzepatide, depression scores did not rise on the medicine compared with placebo among people without known major psychiatric illness, and suicidal thoughts or behaviour were reported at similar rates in both groups. A pooled analysis of 27 randomised trials with 59,396 participants found very few suicide or self-harm events on GLP-1 medicines or on placebo, and no significant difference between them. EMA's safety committee concluded in April 2024 that the available evidence does not support a causal association between five GLP-1 receptor agonists, semaglutide among them, and suicidal or self-injurious thoughts and actions, and the US labels for semaglutide 2.4 mg and tirzepatide list the suicidal behaviour and ideation warning as removed in February 2026 (US labels). These analyses looked at people without known major psychiatric illness, so they say less about people who already have depression, and any change in mood while on treatment is worth telling your doctor.

Question 19

Can GLP-1 cause anxiety?

Accepted Answer

Anxiety is not listed as an adverse reaction in the adult trial tables of the US labels for semaglutide 2.4 mg or tirzepatide, and it appears in the Medication Guides only among the signs of low blood sugar, a risk the guides tie to taking insulin or a sulfonylurea (US Medication Guides). In the pooled STEP and SURMOUNT analyses, psychiatric adverse events were generally balanced between the medicine and placebo. A 2026 systematic review found the evidence on anxiety mixed, drawn largely from observational cohorts, and called for randomised trials to establish cause and effect. Feeling anxious, low or unlike yourself on treatment is worth telling your doctor.

Question 20

Can GLP-1 cause heart palpitations, and does GLP-1 raise heart rate?

Accepted Answer

A small average rise in resting heart rate is a labelled effect of GLP-1 medication: in the US trials it was 1 to 4 beats per minute with semaglutide 2.4 mg and 1 to 3 with tirzepatide (US semaglutide label; US tirzepatide label). More adults on semaglutide than on placebo had a peak rise of 20 beats per minute or more at some visit (26% against 16%) (US label). The semaglutide label asks patients to tell their healthcare provider about palpitations or a racing heartbeat at rest, and the European information for tirzepatide reports no difference in arrhythmia events between tirzepatide and placebo in its weight-management study (3.3% to 3.7% against 3.6%) (US label; EU label). Palpitations or a racing heartbeat while resting are worth reporting to your doctor.

Question 21

Can GLP-1 cause low blood pressure?

Accepted Answer

Yes, low blood pressure is a recorded side effect, though not a common one: the US labels report hypotension-related reactions in 1.3% of adults on semaglutide 2.4 mg against 0.4% on placebo, with fainting in 0.8% against 0.2%, and hypotension in 1.6% on tirzepatide against 0.1% on placebo (US semaglutide label; US tirzepatide label). It was reported more often in people also taking blood pressure medicines (2.2% against 1.2% on tirzepatide), and some cases came with vomiting, diarrhoea or dehydration (US semaglutide label; US tirzepatide label). Tell the doctor which blood pressure medicines you take, and report dizziness or fainting on standing.

Question 22

What vitamins to take with GLP-1?

Accepted Answer

No vitamin or supplement is part of the labelled use of GLP-1 medication: the US Medication Guides only ask patients to tell their healthcare provider about all the medicines they take, including vitamins and herbal supplements (US Medication Guides). The concern is eating much less: a joint advisory from four US nutrition and obesity societies says the large fall in appetite and intake "can lead to insufficient intakes of essential vitamins and minerals", and that dietary supplements "can be proactively considered for at-risk nutrients … at appropriate doses and tailored to each person's needs". That is expert guidance rather than trial evidence: a consensus statement published in late 2025 says its recommendations were "primarily derived from indirect evidence" and that "further direct evidence is urgently required", and a PubMed search found few published randomised trials of magnesium, iron, B12 or probiotics in people taking these medicines, and trials of probiotics in people taking semaglutide are registered. Which supplement, if any, suits you depends on what you eat and on your own nutrient levels, which is a question for your doctor.

Question 23

Can GLP-1 cause B12 deficiency?

Accepted Answer

Eating much less can lead to nutrient gaps, and a retrospective claims analysis of 461,382 adults newly prescribed GLP-1 medication between 2017 and 2021, most of them with type 2 diabetes, found nutritional deficiencies diagnosed in 12.7% within 6 months and 22.4% within 12 months, vitamin D deficiency being the most common (7.5% and 13.6%). Deficiency is not listed as an adverse reaction in the US or European product information, and the figures are observational, so they cannot show that the medicine caused the deficiency; diagnoses were also recorded more often in people who saw a dietitian. A joint advisory from four US nutrition and obesity societies names iron, calcium, magnesium, zinc and vitamins A, D, E, K, B1, B12 and C as nutrients of concern when intake falls, and lists fatigue beyond what is expected, muscle weakness, poor wound healing and unusual bruising as signs of frank deficiency. Those signs are worth raising with your doctor, who can decide whether a blood test is needed.

Question 24

Does GLP-1 help with menopause symptoms?

Accepted Answer

No randomised trial has yet reported on GLP-1 medication for menopause symptoms such as hot flushes: the only items a PubMed search turns up are a scoping review, which says studies reporting improved vasomotor symptoms (such as hot flushes) were limited and that "further research is needed", and a case report in which hot flushes worsened. What has been studied for GLP-1 medication after menopause is weight, not symptoms, and no dedicated randomised trial has reported in postmenopausal women. Hot flushes and other menopause symptoms are for your own doctor or gynaecologist to assess.

Question 25

Can GLP-1 affect your period?

Accepted Answer

Menstrual changes are not listed as a side effect in the US or European product information for semaglutide 2.4 mg or tirzepatide. In polycystic ovary syndrome (PCOS), the most recent systematic review of randomised trials rated the evidence insufficient to draw any conclusion about menstrual regularity. In women with PCOS, weight loss can restore ovulation in those who were not ovulating, so fertility can return before anyone expects it, which is why the PCOS guideline asks for effective contraception whenever pregnancy is possible. A change in your cycle, or any bleeding after menopause, is worth raising with your doctor.

Common questions about GLP-1 medication in Singapore

Side effects and safety