Last reviewed: January 2026
Week-by-week injection schedule for semaglutide, tirzepatide, and retatrutide — with exact syringe draw amounts.
GLP-1 medications must be titrated (started at a low dose and gradually increased) to minimize gastrointestinal side effects — particularly nausea, vomiting, and diarrhea. The titration schedule allows your gut to adapt to slowed gastric motility. Moving too fast increases side effects significantly. Many clinicians recommend extending each step to 6–8 weeks rather than 4 for better tolerability, especially at higher doses.
What if I experience severe nausea? Stay at your current dose for an extra 2–4 weeks before escalating. Most nausea improves substantially after 4–8 weeks at any given dose level. Eating smaller, lower-fat meals and avoiding lying down after eating helps significantly.
See also: Peptide Cycle Planner · Peptide Dose by Body Weight Calculator · Peptide Stack Calculator · Peptide Storage Calculator · Burnout Risk Calculator
→ Use this as a starting point, not a diagnosis. Online calculators provide estimates based on population averages. Your individual results may vary — consult a healthcare professional for personalized medical advice.
→ Measure consistently. For the most accurate tracking, take measurements at the same time of day under the same conditions each time you use this calculator.
→ Track trends, not single data points. One measurement is a snapshot. Track results over weeks and months to see meaningful patterns and progress.
→ Combine with related tools. Use this alongside other health calculators on this site for a more complete picture of your fitness and wellness metrics.
→ Semaglutide titration: 0.25mg → 0.5mg → 1.0mg → 1.7mg → 2.4mg (Wegovy). Each dose level lasts 4 weeks minimum. The full titration from 0.25mg to the maintenance dose takes 16–20 weeks. Rushing the schedule increases nausea and GI side effects significantly.
→ GI side effects are worst during titration, not at maintenance. Nausea, constipation, and reduced appetite are most intense in the first 2–4 weeks at each new dose level, then typically improve. If side effects are severe, your prescriber may extend a dose level before advancing.
→ You don't have to reach the maximum dose. Some patients achieve their goals at intermediate doses (e.g., 1.0 or 1.7mg semaglutide). Higher doses have more side effects. Your prescriber may recommend staying at a lower dose if it's effective for you.
→ Inject on the same day each week, but the exact time doesn't matter. Pick a consistent day (e.g., every Sunday). If you miss a day, inject within 5 days; if more than 5 days late, skip that dose and resume on your normal day. See our GLP-1 Weight Loss Projector for expected results.
See also: GLP-1 Weight Loss · GLP-1 Savings · BMI Calculator · Calorie Calculator
A GLP-1 titration tracker maps out the recommended dose escalation schedule for GLP-1 medications, showing when to increase from starting doses to maintenance doses. Following proper titration reduces side effects and helps patients adjust to the medication safely.
| Week | Dose | Purpose | Common Side Effects |
|---|---|---|---|
| Weeks 1–4 | 0.25 mg | Initiation | Mild nausea |
| Weeks 5–8 | 0.5 mg | Dose escalation | Nausea, decreased appetite |
| Weeks 9–12 | 1.0 mg | Therapeutic dose | GI symptoms may increase |
| Weeks 13–16 | 1.7 mg | Escalation (if needed) | Similar to previous |
| Week 17+ | 2.4 mg | Maximum dose | Usually well-tolerated by now |
GLP-1 receptor agonists mimic a natural hormone called glucagon-like peptide-1 that your body produces after eating. This hormone signals the pancreas to release insulin, slows stomach emptying, and reduces appetite by acting on brain centers involved in satiety. The medications — including semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound), and liraglutide (Saxenda, Victoza) — amplify these effects far beyond what the body produces naturally. Because the pharmacological doses are much stronger than natural GLP-1 levels, the body needs time to adjust — which is why titration exists. Starting at the maximum dose would overwhelm the GI system and cause severe nausea, vomiting, and potentially dangerous dehydration in most patients.
Tirzepatide (Mounjaro/Zepbound) follows a similar escalation approach but uses different dose increments and acts on both GLP-1 and GIP receptors — a dual agonist mechanism that may produce greater weight loss and glycemic control in some patients.
| Phase | Dose | Duration | Notes |
|---|---|---|---|
| Initiation | 2.5 mg | Weeks 1–4 | Adjustment period, minimal therapeutic effect |
| Step 2 | 5.0 mg | Weeks 5–8 | First therapeutic dose |
| Step 3 | 7.5 mg | Weeks 9–12 | Escalation if needed |
| Step 4 | 10.0 mg | Weeks 13–16 | Higher therapeutic range |
| Step 5 | 12.5 mg | Weeks 17–20 | Near-maximum dose |
| Maximum | 15.0 mg | Week 21+ | Highest approved dose |
| Feature | Semaglutide | Tirzepatide |
|---|---|---|
| Mechanism | GLP-1 agonist | GLP-1 + GIP dual agonist |
| Starting dose | 0.25 mg | 2.5 mg |
| Maximum dose | 2.4 mg (Wegovy) | 15.0 mg |
| Titration duration | 16–20 weeks | 20–28 weeks |
| Dose steps | 5 levels | 6 levels |
| Injection frequency | Once weekly | Once weekly |
| Average weight loss (trials) | ~15% body weight | ~20–22% body weight |
Gastrointestinal side effects affect 40–70% of patients during titration, with nausea being the most common. These symptoms typically peak 2–3 days after each dose increase and gradually subside over 1–2 weeks. The titration schedule is specifically designed to minimize this impact — each 4-week interval gives your GLP-1 receptors and digestive system time to downregulate and adapt before the next increase. Patients who experience persistent or severe symptoms should discuss extended titration intervals with their provider rather than discontinuing the medication entirely.
| Side Effect | Frequency | Typical Duration | Management Strategy |
|---|---|---|---|
| Nausea | 40–50% | 2–4 weeks per dose step | Eat smaller meals, avoid fatty foods |
| Decreased appetite | 30–40% | Ongoing (therapeutic) | Prioritize protein intake |
| Diarrhea | 15–25% | 1–2 weeks per dose step | Stay hydrated, avoid high-fiber meals initially |
| Constipation | 10–20% | Variable | Increase water and fiber gradually |
| Injection site reactions | 5–10% | 24–48 hours | Rotate injection sites (abdomen, thigh, arm) |
| Fatigue | 10–15% | First 2–3 weeks | Ensure adequate caloric and protein intake |
Patients who follow the recommended titration schedule are significantly more likely to reach and maintain their target dose compared to those who attempt rapid escalation or skip steps. Clinical trial data shows that 85–90% of patients who complete proper titration continue therapy at 12 months, while those who experience severe early side effects from rushed dosing have a discontinuation rate exceeding 30%. The gradual approach also helps patients develop sustainable eating habits as their appetite naturally decreases — rather than being hit with a sudden and dramatic reduction in hunger that can lead to inadequate nutrition.
Proper nutrition during titration is critical. As appetite decreases, patients need to prioritize high-quality protein (0.8–1.0 grams per kilogram of body weight daily) to preserve lean muscle mass during weight loss. Inadequate protein intake during GLP-1 therapy can accelerate muscle loss, which reduces metabolic rate and makes long-term weight maintenance more difficult. Many clinicians recommend patients track protein intake during the first few months of therapy to ensure they meet minimum targets despite eating less overall. Use our Calorie Calculator to estimate your adjusted caloric needs during treatment.
Not every patient follows the textbook titration path. Several common scenarios require modification of the standard schedule. If side effects are severe at a particular dose, providers often extend that step to 6–8 weeks instead of 4 before attempting the next increase. If a patient achieves their weight loss or A1C target at a mid-range dose, they may remain at that level indefinitely without escalating further — there is no clinical requirement to reach the maximum dose. Patients who stop the medication for more than 2 weeks should discuss restarting at a lower dose with their provider, as tolerance built during previous titration may have diminished.
Healthcare providers typically monitor several markers during GLP-1 titration to ensure safety and effectiveness. Blood glucose levels should be checked regularly, especially for diabetic patients on concurrent insulin or sulfonylurea therapy, as the combination can cause hypoglycemia. Kidney function panels are recommended before starting therapy and periodically during treatment, since dehydration from nausea and reduced fluid intake can stress the kidneys. Heart rate monitoring is also important — GLP-1 agonists can increase resting heart rate by 2–4 beats per minute on average, which is clinically insignificant for most patients but should be evaluated in those with pre-existing cardiac conditions. Weight should be recorded at each dose step to track trajectory and inform decisions about further escalation. Use our BMI Calculator to track your progress alongside the titration schedule.
→ Inject on the same day each week. Consistency helps maintain steady medication levels. Pick a day that works with your schedule and set a recurring reminder.
→ Eat protein first at every meal. With reduced appetite, protein should be your priority to preserve muscle mass. Aim for 25–30g per meal.
→ Stay hydrated. GLP-1 medications slow gastric emptying, which can reduce your natural thirst signals. Aim for at least 64 oz of water daily, more if experiencing nausea or diarrhea.
→ Don't skip steps to speed things up. The 4-week intervals exist for a reason — rushing increases side effect severity and discontinuation risk without improving outcomes.
See also: Calorie Calculator · BMI Calculator · Body Fat Calculator · Calorie Deficit
GLP-1 medications carry significant list prices — semaglutide (Wegovy) lists at approximately $1,300–$1,400 per month, while tirzepatide (Zepbound) runs around $1,000–$1,100 per month without insurance. Coverage varies widely by plan and indication. Most commercial insurers cover these medications for type 2 diabetes management but may require prior authorization for weight management indications. Medicare Part D covers GLP-1 agonists prescribed for diabetes but has historically excluded weight-loss-only prescriptions, though recent policy changes have expanded access. Patients without coverage should ask their provider about manufacturer savings programs, which can reduce out-of-pocket costs to $25–$150 per month for eligible individuals with commercial insurance.
During FDA-recognized shortages, compounding pharmacies have been permitted to produce semaglutide and tirzepatide at lower cost. Compounded versions typically cost $150–$400 per month compared to $1,000+ for brand-name products. However, compounded medications are not FDA-approved, may vary in potency and sterility, and their availability depends on ongoing shortage declarations. The FDA has taken enforcement action against some compounders, and patients should only use compounded versions from licensed 503B outsourcing facilities that follow current good manufacturing practices. Discuss the risks and benefits with your prescriber before choosing a compounded product. Patients should verify that their compounding pharmacy is registered with the FDA and their state board of pharmacy.
During the initiation phase at the lowest dose, most patients notice mild appetite reduction and occasional nausea. Weight loss during this phase is minimal — typically 1–3 pounds — because the dose is sub-therapeutic and primarily serves to acclimate your body to the medication. By the second dose step, appetite suppression becomes more noticeable and weight loss begins in earnest. Most patients lose 3–5% of their body weight during the first 8 weeks of titration. The middle escalation phases are where side effects tend to peak — this is the most common point of discontinuation, so maintaining communication with your provider is essential. By the time you reach your maintenance dose, your body has largely adapted, side effects have diminished, and weight loss occurs at a steady rate of 1–2% of body weight per month.
Exercise during titration should be moderate. Intense workouts combined with reduced caloric intake and potential nausea can lead to dizziness, muscle breakdown, and electrolyte imbalances. Walking, light resistance training, and yoga are well-tolerated during the early phases. As you stabilize at your maintenance dose and learn to eat adequately on reduced appetite, you can gradually increase exercise intensity. Resistance training becomes especially important during GLP-1 therapy to counteract lean mass loss — patients who combine the medication with structured strength training preserve significantly more muscle than those who rely on the medication alone.
GLP-1 therapy is generally considered a long-term or indefinite treatment. Clinical studies consistently show that patients who discontinue the medication regain a significant portion of lost weight within 12–18 months — typically 60–70% of the weight lost during treatment. This rebound occurs because the medication's effects on appetite, gastric emptying, and metabolic signaling cease upon discontinuation. For this reason, most endocrinologists and obesity medicine specialists recommend viewing GLP-1 therapy as an ongoing treatment rather than a temporary intervention. Patients who wish to discontinue should taper gradually under medical supervision and have a structured diet, exercise, and behavioral plan in place to mitigate weight regain. The decision to stop should be made collaboratively with your healthcare provider based on your individual health goals, risk factors, and response to therapy.