This is the third part of our monthly blog series on the latest insights in metabolic medicine.
You’ve done your research, reviewed the indications, and are now considering starting GLP-1 therapy? Then this post is exactly right for you. As a doctor, it’s important to me that you not only know the benefits, but also understand what to realistically expect—transparent and without sugarcoating—so you can start well prepared and safely.
If you’d like an overview of the official areas of use before your GLP-1 start, this article can help: What are GLP-1 agonists approved for? Indications and off-label use.
GLP-1 treatment process: how treatment begins
GLP-1 start step 1: before the first injection – preparation
Before you begin therapy, there’s a structured pre-treatment consultation. Scheduling—just like the appointment booking—is handled by our medical assistant team. During the medical consultation, we take the time to accurately assess your starting situation: What pre-existing conditions do you have? Which medications are you taking? Are there allergies or any special considerations we need to know about?
If you come to an appointment at one of our clinics, a physical exam may also be part of it depending on the situation—for example weight, blood pressure, and BMI calculation. In addition, lab values may be useful depending on your individual situation. Often, this includes metabolic markers such as HbA1c and fasting glucose, as well as liver and kidney values and blood lipids. In some cases, lipase and thyroid values are also determined. The goal is not “as much diagnostics as possible,” but a safe basis for therapy decisions.
Another important part of preparation is education: we talk about the mechanism of action and realistic expectations, possible GLP-1 therapy side effects (and how they can often be managed well), injection technique, nutrition (for example protein-rich meals and eating slowly), and the need for regular check-ups. Depending on the situation, we also clarify cost coverage and choose the most suitable medication together. Therapy-accompanying nutritional counseling is part of our concept.
Related: Do’s & Don’ts – Nutrition During Medication-Assisted Weight Loss.
GLP-1 treatment process step 2: dose escalation – start slowly, tolerate better
Many side effects occur mainly when the dose is increased too quickly. Your body needs time to get used to the medication. That’s why the dose is usually increased step by step—not “rigidly according to plan,” but adjusted to tolerability and effect.
For example, semaglutide (Wegovy®) is often started at a low dose and then increased at intervals of several weeks. With tirzepatide (Mounjaro®), a gradual start is also common, with optional stepwise increases.
To give you a concrete point of reference, here are two typical starting schedules (the exact implementation is always individual):
- Typical schedule for semaglutide (Wegovy®): Weeks 1–4: 0.25 mg/week, Weeks 5–8: 0.5 mg/week, Weeks 9–12: 1.0 mg/week – optional further increases at intervals to 1.7 mg up to 2.4 mg (individual based on tolerability and effect). Note: Studies are currently ongoing with doses up to 7.2 mg.
- Typical schedule for tirzepatide (Mounjaro®): Weeks 1–4: 2.5 mg/week, Weeks 5–8: 5.0 mg/week – optional: further increases at intervals to 7.5 mg, 10 mg, or 15 mg (depending on tolerability and effect).
Important: Dose escalation is individual. If stronger side effects occur, we stay longer at a lower dose. A pragmatic principle often applies: as low as possible, as high as necessary—and increasing mainly when the effect/weight loss plateaus and tolerability is good.
GLP-1 treatment process step 3: injection – easier than you think
GLP-1 medications are injected into subcutaneous fat tissue (subcutaneously). Many patients feel unsure at first and are then surprised how well it works in everyday life.
Typical injection sites are the lower abdomen (with distance from the navel), the thigh (front), or the upper arm (back; often harder to reach yourself). Typically, the injection is once per week, ideally always on the same day of the week. The time of day is usually less important; consistency matters more.
A few practical details often make it more comfortable: many find it less unpleasant if the pen is taken out of the refrigerator about 30 minutes before the injection. The injection site should also be changed weekly. After the injection, it can be helpful to keep the pen in the skin for a few seconds. A suitable sharps container (e.g., from a pharmacy) is recommended for needle disposal.
GLP-1 start step 4: regular check-ups – safety first
Especially in the beginning, check-ups are important to manage effect, tolerability, and—if applicable—concomitant medication. In the first months, appointments often take place at roughly four-week intervals, later at longer intervals, for example every three months. Depending on the situation, lab checks may be included, such as HbA1c, liver and kidney values, and lipase.
In addition, it’s useful to document weight progression and regularly talk about nutrition and lifestyle. Sometimes blood levels of certain medications need to be monitored and dosages adjusted. That’s also part of safe support.
GLP-1 therapy side effects: what you may experience at the start (and what often helps)
Many side effects occur mainly in the first weeks or with dose increases. The good news: with a few adjustment levers, symptoms can often be reduced significantly. The key is to take symptoms seriously early—and not “push through at any cost.”
Nausea and vomiting
A common reason for nausea is slowed gastric emptying. This creates a feeling of fullness more quickly—especially when portions are still (too) large.
What often helps in everyday life is less complicated than many think: smaller, more frequent meals instead of fewer large portions, eating more slowly and chewing well, and often a more protein-rich and, in the start phase, lower-fat diet. Many people also tolerate large amounts of fluid directly with meals less well. Ginger tea or peppermint tea (if tolerated) can help, as can acupressure bands like those used for motion sickness. For severe nausea, medication may be an option after consultation.
Further reading: Nausea and weight loss injections: tips for digestion.
Many patients report that nausea noticeably improves after a few weeks—especially when eating habits are adjusted and dose escalation is kept calm and gradual.
Constipation
Constipation often results from a combination of slowed bowel movement and overall reduced food intake. The basics often help: drinking enough (if there’s no medical reason against it), slowly increasing fiber (e.g., psyllium, flaxseed, vegetables), and regular movement. If needed, a gentle laxative such as macrogol can be used after consultation.
Fatigue and headaches
Fatigue and headaches often have multiple possible causes: too little energy intake, too little fluid, dehydration, or an electrolyte imbalance. In practice, it’s therefore useful to first check the “simple” factors: Are you eating enough regularly? Are you drinking enough? Are you sleeping enough?
Helpful here: Water, electrolytes & co. – what your body really needs for rapid weight loss.
Some patients use rough calorie ranges in the start phase (e.g., 1200–1500 kcal/day). However, this depends on height, activity level, and goal and should not be understood as a rigid requirement. If you feel clearly weak, that’s a signal to discuss the situation medically.
Eating too little is often underestimated in practice: What if I eat too little during therapy? – The underestimated risk.
Heartburn and reflux
Reflux can also occur in the start phase. Smaller meals, not lying down right after eating, and—if needed—raising the head of the bed can help. Acid blockers (PPIs) can be used after consultation.
GLP-1 start: conclusion – start informed, stay closely supported
GLP-1 therapies are effective medications, and especially in the start phase the rule is: increase slowly, observe carefully, and use the available adjustment levers. If you start prepared, take check-ups seriously, and address side effects early, the therapy is manageable for many patients. In short: a clear weight loss injection treatment process plus good support makes the difference.
Outlook
If the start phase feels bumpy: you’re not alone. In the next blog post, you’ll get concrete strategies to reduce side effects step by step, plus a clear warning-sign checklist so you can confidently assess when you should contact your medical team.
Source
Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. DOI: 10.1056/NEJMoa2032183