A practical week-by-week guide to beginning treatment — what to expect, what to do, and how to feel your best as your body adjusts.
Your first week is about starting your medication and letting your body begin to adjust. GLP-1 medications are self-administered as a small subcutaneous injection — just under the skin — once weekly. Most patients describe the sensation as a minor pinch, and your 1stRX provider will walk you through proper injection technique before your first dose.
Most patients experience some nausea and reduced appetite almost immediately. This is a normal part of your body adapting to the medication. Weight loss in this period is modest as your body adjusts — the most important thing is to take your medication as directed and don't skip doses.
Side effects are often most noticeable now. Side effects typically peak during weeks 2–3 and begin to subside. The most common side effects are gastrointestinal and are usually mild to moderate — knowing what's normal makes them far easier to manage.
The most common side effect. Typically occurs 1–2 days after injection. Eat smaller meals, avoid greasy/spicy foods, take your injection at night before bed, and try ginger tea or crackers.
Slowed gastric emptying can cause constipation. Increase fiber and water intake. Probiotics can help. Avoid high-fat meals which can trigger diarrhea.
Reduced calorie intake can cause temporary tiredness, especially in weeks 1–3. Prioritize sleep, protein intake, and light activity. This typically resolves within the first month.
Seek immediate medical attention if you experience severe abdominal pain that doesn't go away, signs of pancreatitis (severe pain radiating to your back), gallbladder problems, severely rapid heart rate, or signs of an allergic reaction. Contact your 1stRX provider if side effects are persistent or significantly impacting your quality of life.
For many patients, this is the turning point. Side effects typically peak during weeks 2–3 and begin to subside. Most patients notice a dramatic reduction in food cravings and the volume of food they can comfortably eat — which makes it the right time to focus on the quality of what you eat.
Protein is the most critical macronutrient on GLP-1 therapy. Without enough protein, you risk losing muscle mass alongside fat. Aim for 0.7–1g of protein per pound of goal body weight daily — lean meats, eggs, Greek yogurt or cottage cheese, legumes, and protein shakes (especially useful when appetite is suppressed).
By the end of your first month, side effects have usually eased and new habits are taking hold. Expect to lose approximately 1–2% of your body weight in the first month.
Months 2–3 are your titration phase: your dose will be gradually increased during this period. As doses increase, you may experience mild side effects again temporarily — this is normal, and weight loss typically accelerates. For the fuller picture of what comes after month one, see the 12-Month GLP-1 Journey.
Your care team checks in regularly to monitor your progress, adjust dosing as needed, and answer any questions you have — all through secure messaging or video.
An at-a-glance recap of your first four weeks.
Take your first dose, hydrate (at least 64–80 oz of water daily), and rotate your injection sites. Don't skip doses.
Side effects may peak — manage nausea, GI changes, and fatigue, and know when to contact your provider.
Side effects begin to subside. Focus on protein and nutrient-dense meals.
Assess your progress and prepare for dose titration, which begins in months 2–3.
Yes. Side effects typically peak during weeks 2–3 and begin to subside — this is normal and expected as your body adapts to the medication. The most common side effects are gastrointestinal and are usually mild to moderate.
Seek immediate medical attention if you experience severe abdominal pain that doesn't go away, signs of pancreatitis (severe pain radiating to your back), gallbladder problems, severely rapid heart rate, or signs of an allergic reaction. Contact your 1stRX provider if side effects are persistent or significantly impacting your quality of life.
Expect to lose approximately 1–2% of your body weight in the first month. Weight loss in the first week or two is typically modest as your body adjusts, and most patients notice a dramatic reduction in food cravings during this time.
Dose increases (titration) generally begin around months 2–3, following your clinician's guidance. See the 12-Month GLP-1 Journey for the fuller picture of what to expect after your first month.
If you're switching providers rather than starting fresh, your first-month experience may differ, since you may already be past initial titration and continuing at your current dose. See How to Switch GLP-1 Providers for guidance specific to transferring your care.
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