Checklist: Monitoring GLP-1 Side Effects

GLP-1 medications are widely used in Singapore for weight management and type 2 diabetes. They work by reducing appetite, slowing stomach emptying, and regulating hormones. While effective, they can cause side effects, particularly in the early weeks, which require close monitoring. Here's what you need to know:

Daily checks: Watch for nausea, diarrhoea, vomiting, bloating, and appetite changes. Stay hydrated and eat smaller, lighter meals.
Weekly checks: Track dizziness, fatigue, injection site reactions, and weight changes. Rotate injection sites and monitor your resting heart rate.
Monthly checks: Look out for signs of pancreatitis, gallbladder issues, kidney problems, or thyroid changes. Severe abdominal pain or jaundice requires immediate medical attention.
Serious risks: Seek emergency care for severe dehydration, allergic reactions, or vision changes.

Both oral and injectable GLP-1 options share common side effects but differ in administration and some unique risks. Regular follow-ups with your doctor are key to safe and effective treatment.

GLP-1 Side Effects Monitoring Schedule: Daily, Weekly, and Monthly Checklists

Answering Your Questions About GLP-1s | Keren Zhou, MD

Daily Side Effects Checklist

Tracking how you feel each day can help you identify patterns and address potential issues early. Side effects are most likely to occur during the first few weeks of starting GLP-1 medications.

Digestive Symptoms

The most common daily side effects include nausea, diarrhoea, vomiting, constipation, bloating, indigestion, heartburn, gas, and belching. Studies show that 40% to 70% of people on GLP-1 medications experience nausea at some point. For instance, clinical trials for Wegovy (2.4 mg) reported nausea in 44% of participants, diarrhoea in 30%, and vomiting in 24%.

To minimise dehydration caused by digestive discomfort, aim for at least 1.9 litres of fluids daily. Opt for ice-cold drinks, ginger or lemon tea, and electrolyte-rich options like coconut water, sports drinks, or bone broth.

"Staying upright for at least 30 minutes after eating is very helpful to avoid nausea because it more easily allows the food to pass through the stomach using gravity." - Micheal Currier, PA-C

Simple changes to eating habits can also help. Eat smaller portions slowly, avoid lying down immediately after meals, and steer clear of fried, greasy, or sugary foods. If nausea occurs, plain carbohydrates such as wheat toast, crackers, rice, oatmeal, or applesauce are gentler on the stomach. Stop eating as soon as you feel full - overeating can lead to nausea or vomiting.

Pay attention to appetite changes as well, as they can indicate how well the medication is working.

Appetite and Weight Changes

GLP-1 medications are designed to reduce hunger and slow down stomach emptying. Many people notice reduced hunger and cravings within the first two to four weeks of treatment. You may find yourself feeling full faster, experiencing fewer cravings (especially for fatty or sweet foods), and naturally eating smaller portions.

Track these changes daily - reduced hunger, quicker satiety, and fewer cravings are signs that the medication is working as intended. If your appetite becomes so suppressed that eating feels challenging, try having smaller, more frequent meals instead of three large ones. Additionally, drink fluids 30–60 minutes before or after meals rather than during, to avoid feeling overly full too quickly.

Weekly Side Effects Checklist

Weekly check-ins can help you spot subtle changes, especially after adjusting your medication dose.

Body-Wide Symptoms

You might notice dizziness, fatigue, or headaches, particularly when starting or increasing your dosage. To manage these, stay hydrated, avoid skipping meals, and keep some fast-acting carbohydrates on hand to counter symptoms of low blood sugar such as shakiness, sweating, or dizziness.

If you're on injectable GLP-1 medications, inspect your injection site weekly for any signs of irritation. Rotate injection spots between your abdomen, thigh, and upper arm to minimise issues. Also, keep an eye on your resting heart rate - report any significant changes to your healthcare provider.

Less common symptoms include hair thinning and facial sagging. In clinical trials for Wegovy, 3% of participants reported hair loss compared to 1% in the placebo group. These symptoms are usually tied to rapid weight loss rather than the medication itself, so aiming for gradual weight loss can help reduce these effects.

Track these symptoms alongside your weekly weight updates for a clearer picture of your progress.

Weight Loss Tracking

You may notice reduced hunger within two to four weeks, but visible weight changes generally take shape between weeks 8 and 12 as your dose is fine-tuned. For a more comprehensive view, track not just your weight but also your waist circumference and blood pressure on a weekly basis.

If you have diabetes, keep a close watch on your fasting glucose levels to quickly address any sudden drops. Maintaining a weekly symptom diary can also help you identify trends and ensure your treatment plan stays on track.

Monthly Side Effects Checklist

Monthly checks focus on spotting rare but serious complications that may not show up during daily or weekly observations. If you're using GLP-1 medications, take time each month to assess for these potential issues.

Gallbladder and Pancreas Health

Be on the lookout for severe, persistent stomach pain that doesn’t go away - especially if it spreads to your back. This could be a warning sign of pancreatitis, a serious inflammation of the pancreas. Clinical trials for semaglutide have estimated the risk of pancreatitis at about 0.2% to 0.5%. Though severe pancreatitis is uncommon, it demands immediate attention. If this pain is paired with fever and ongoing vomiting, stop taking the medication and head to the emergency room right away.

Other signs to watch for include upper right abdominal pain, yellowing of the skin or eyes, or clay-coloured stools. If these symptoms come with fever or chills, seek medical advice immediately.

Kidney and Thyroid Health

Pay attention to signs of kidney issues such as reduced urination, swelling in the legs or ankles, or sudden weight gain. Staying well-hydrated can help reduce strain on your kidneys.

Once a month, check your neck for lumps, swelling, persistent hoarseness, or trouble swallowing. Identifying potential thyroid problems early is crucial. The official Wegovy safety information advises:

"Tell your healthcare provider if you get a lump or swelling in your neck, hoarseness, trouble swallowing, or shortness of breath. These may be symptoms of thyroid cancer."

If you have diabetes, also keep an eye out for sudden vision changes or blurring during your monthly checks. GLP-1 medications have been linked to a rare condition called Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION).

When to See a Doctor Immediately

Some side effects shouldn't be ignored and require urgent medical attention.

If you're experiencing severe, persistent stomach pain that radiates to your back and doesn’t improve with position changes, stop taking the medication and head to the emergency room right away. This could be a sign of pancreatitis.

Be alert for signs of severe dehydration. If you’re unable to keep liquids down for 24 hours, notice a significant drop in urination, swelling in your feet or ankles, or feel confused, seek immediate help. Severe dehydration caused by ongoing vomiting or diarrhoea can lead to kidney problems.

Allergic reactions also require emergency care. If you notice swelling in your face, eyes, lips, or tongue, have trouble breathing, or develop an itchy rash spreading across your body, get help immediately. Other internal complications may also need urgent attention.

Pay attention to upper right abdominal pain accompanied by fever, chills, or yellowing of your skin or eyes (jaundice). These could indicate gallbladder issues.

For diabetics using GLP-1s along with insulin or sulfonylureas, it’s crucial to act quickly if your blood glucose drops below 70 mg/dL. Treat it immediately with about 125 ml of fast-acting carbohydrates, such as juice, to prevent further complications.

Sudden changes in vision, like blurriness or seeing floaters, should be evaluated by a doctor without delay.

Lastly, if you experience severe depression or have thoughts of self-harm while on GLP-1 medications, reach out to your healthcare provider or seek emergency mental health support right away.

Oral vs Injectable GLP-1 Side Effects

When considering oral versus injectable GLP-1 medications, it's crucial to understand how their side effects differ and what monitoring steps are necessary.

Both oral and injectable GLP-1 medications share common gastrointestinal side effects, such as nausea, vomiting, diarrhoea, and constipation. According to the MHRA, these issues can persist for several days and affect more than 10% of patients. These symptoms are often most intense during the first few weeks of treatment or after a dose adjustment but tend to ease as the body adapts.

Injectable options like Ozempic, Wegovy, and Mounjaro may lead to injection site reactions, such as redness, swelling, or pain, particularly if injection sites are not rotated regularly. On the other hand, the oral medication Rybelsus (semaglutide) eliminates this issue but requires specific administration steps. It must be taken on an empty stomach with no more than 120 ml of water, followed by a 30-minute wait before consuming any food or drink.

Some less common side effects differ between the two forms. Both types carry rare but serious risks, including pancreatitis, gallbladder problems, and kidney injury due to dehydration. Injectable formulations may also be associated with complications like diabetic retinopathy, making it essential to monitor for changes in vision. Below is a detailed comparison of the side effects and monitoring tips for each formulation.

Side Effect Comparison Table

Side Effect Category	Oral GLP-1 (Rybelsus)	Injectable GLP-1 (Ozempic, Wegovy, Mounjaro)	Monitoring Advice
Digestive	Nausea, vomiting, diarrhoea, constipation, abdominal pain, indigestion	Nausea, vomiting, diarrhoea, constipation, bloating, reflux	These symptoms usually improve over time. Eating smaller, more frequent meals and avoiding greasy foods can help.
Body-Wide	Fatigue, weakness, dizziness, headache, decreased appetite	Fatigue, low energy, slight increase in heart rate, headache	Keep track of your energy levels and ensure adequate nutrition, even with reduced appetite.
Unique/Rare	Changes in taste, hair loss, nausea tied to improper timing of medication	Injection site reactions (redness, swelling, itching, bruising, pain)	Follow administration guidelines: adhere to the 30-minute fasting rule for oral tablets and rotate injection sites for injectables.
Serious Risks	Pancreatitis, gallbladder issues, kidney injury (via dehydration)	Pancreatitis, gallbladder issues, kidney injury, diabetic retinopathy complications	Seek immediate medical attention for severe abdominal pain or vision changes.

"For patients who struggle with daily medication routines, a once-weekly injection can make a meaningful difference to consistency." - Dr. Jana Lim, Family Physician at Singapore Women's Clinic

Ultimately, the choice between oral and injectable GLP-1 treatments often depends on personal preferences and lifestyle needs. Both options share many side effects, but their unique characteristics and administration requirements may influence your decision. Regular check-ins with your healthcare provider are key to managing these medications safely and effectively.

Conclusion

Keeping track of GLP-1 side effects is a key step in protecting your health. While more than 10% of users report gastrointestinal symptoms, most are mild. However, staying alert can help detect rare but serious conditions like pancreatitis or gallbladder disease early on.

Maintaining a daily symptom log can help your doctor fine-tune your dosage. Research shows that most patients achieve at least a 5% reduction in body weight with GLP-1 therapy, but this progress hinges on consistent medical oversight. As Dr. Donovan Tay, Senior Consultant Endocrinologist, explains:

"Minor side effects rarely require discontinuation. Contact your endocrinologist before stopping, as they can adjust doses, recommend management strategies, or prescribe supportive medications to improve tolerance".

It’s important not to alter your dosage on your own. If you experience severe abdominal pain, jaundice, or sudden vision changes, seek medical attention immediately.

Successful GLP-1 treatment goes beyond medication. It thrives on a combination of balanced nutrition, regular exercise, and ongoing medical guidance.

Trimly provides MOH-approved, doctor-led weight loss treatments with unlimited follow-ups, ensuring you’re supported throughout your GLP-1 journey. With medication delivered straight to your doorstep and personalised treatment plans, you can prioritise your health while your medical team monitors your progress every step of the way. Visit https://trimly.sg to explore evidence-based weight loss solutions tailored for Singaporeans.

FAQs

What should I do if I experience severe abdominal pain while taking GLP-1 medication?

If you're on GLP-1 medication and experience severe abdominal pain, stop taking it right away and seek urgent medical care. Reach out to your doctor or head to the nearest emergency department to check for serious issues like pancreatitis.

Severe symptoms should never be ignored - getting prompt medical attention is essential for your health.

What can I do to manage nausea and other digestive side effects of GLP-1 medications?

Nausea and other digestive issues are quite common when starting GLP-1 medications, but the good news is that these side effects can often be managed with a few simple tweaks. Start by using the lowest dose and gradually increase it, giving your body time to adjust. For oral medications, take them on an empty stomach with no more than 120 mL of water, and wait at least 30 minutes before eating or drinking to ensure proper absorption. If you're using injectables, it's best to administer them after a light, low-fat meal while steering clear of rich, spicy, or fried foods.

Eating small, frequent meals can also make a big difference. Options like broth-based soups, bananas, or plain crackers are gentle on the stomach. Ginger tea or ginger chews can be a natural way to ease nausea as well. Staying hydrated is key - aim for 1.5–2 L of water daily - and light activities like a short walk can promote better digestion. If the discomfort continues, speak with your doctor about anti-nausea medication options.

At Trimly, our doctor-led telehealth services are here to support you every step of the way, offering tailored dose adjustments, dietary guidance, and unlimited follow-ups to help you manage side effects while keeping your weight-loss goals on track.

What are the main differences between oral and injectable GLP-1 medications?

Oral GLP-1 medications, like semaglutide tablets, are designed to be taken once a day on an empty stomach. For best results, take them with a small amount of water - no more than 120 mL. To allow proper absorption, wait at least 30 minutes before eating, drinking, or taking any other medications. It’s also important to swallow the tablets whole - don’t split, crush, or chew them.

Injectable GLP-1 medications, such as semaglutide or liraglutide, are administered under the skin (subcutaneously). Depending on the specific medication, injections may be done daily or weekly. These can be taken with or without food, but the technique matters. Always check that the solution is clear and free of particles before injecting it into fatty tissue under the skin.

Oral GLP-1 options require careful timing and fasting, while injectables provide more flexibility but come with the need for proper injection practices.