GLP-1 Medication Calculator
Dosing, weight loss projections, and reconstitution for Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, and Liraglutide.
Titration Schedule Calculator
Get personalized dosing schedules based on your medication and treatment goal
GLP-1 Medication Guide — Semaglutide, Tirzepatide, Retatrutide & More
How GLP-1 Medications Work
GLP-1 (Glucagon-Like Peptide-1) receptor agonists mimic a natural hormone that:
- Reduces appetite by signaling fullness to the brain
- Slows gastric emptying helping you feel fuller longer
- Improves insulin secretion when blood sugar is elevated
- Reduces glucagon preventing excess sugar production
- Promotes weight loss through reduced caloric intake
Medication Comparison — Brand Names & Dosing
Semaglutide
Brands: Ozempic, Wegovy, Rybelsus
Dosing: Once weekly
Weight Loss: ~15% average
Max Dose: 2.4 mg
Tirzepatide
Brands: Mounjaro, Zepbound
Dosing: Once weekly
Weight Loss: ~21% average
Max Dose: 15 mg
Liraglutide
Brands: Victoza, Saxenda
Dosing: Daily
Weight Loss: ~8% average
Max Dose: 3 mg
Retatrutide
Brands: In Clinical Trials
Dosing: Once weekly
Weight Loss: ~24% average
Max Dose: 12 mg
Cagrilintide
Brands: CagriSema (combo)
Dosing: Once weekly
Weight Loss: ~17% average
Max Dose: 2.4 mg
Testosterone
Brands: Various (TRT)
Dosing: Varies
Weight Loss: N/A
Max Dose: Per protocol
Semaglutide Dosing Chart (Ozempic & Wegovy)
Semaglutide is the most prescribed GLP-1 medication. The Ozempic dosing schedule for type 2 diabetes starts at 0.25 mg weekly for 4 weeks, increases to 0.5 mg, then 1 mg, with a maximum of 2 mg. For weight loss, Wegovy dosing follows a longer titration: 0.25 → 0.5 → 1 → 1.7 → 2.4 mg, with each step lasting 4 weeks. Use our calculator above to see the full schedule.
Tirzepatide Dosage Chart (Mounjaro & Zepbound)
Tirzepatide is the newest and most effective GLP-1 medication for weight loss. The Mounjaro dosing and Zepbound dosing schedules are identical, starting at 2.5 mg weekly and increasing every 4 weeks through 5 mg, 7.5 mg, 10 mg, 12.5 mg, to a maximum of 15 mg. Our tirzepatide dosage calculator above shows the complete schedule with dates.
Compounded GLP-1 & Reconstitution
Many patients use compounded semaglutide or tirzepatide from licensed pharmacies. Reconstitution involves mixing powdered peptide with bacteriostatic water. The concentration (mg/mL) determines your injection volume. For example, a 5 mg vial reconstituted with 2 mL water yields 2.5 mg/mL. A 0.5 mg dose requires 0.2 mL. Always verify calculations with your pharmacist and use proper sterile technique.
Common Side Effects
- Nausea - Most common, usually improves after 4-6 weeks
- Diarrhea or constipation - Manage with diet and hydration
- Decreased appetite - Expected effect, ensure adequate nutrition
- Injection site reactions - Rotate injection sites weekly
- Fatigue - Usually temporary during dose escalation
- Heartburn - Common early in treatment
Tips for Success on GLP-1 Medications
- Start with the recommended low dose and titrate slowly to minimize side effects
- Take weekly medications on the same day each week (set a phone reminder)
- Stay well-hydrated, especially if experiencing GI side effects
- Eat smaller, more frequent meals to minimize nausea and maximize nutrition
- Rotate injection sites (abdomen, thigh, upper arm) to prevent irritation
- Store pens and vials in the refrigerator; never freeze
- Track progress with photos and measurements, not just the scale
- Combine medication with protein-focused nutrition and resistance training
- Be patient — weight loss is gradual and sustainable over 6-12 months
When to Contact Your Healthcare Provider
- Severe or persistent nausea and vomiting preventing fluid intake
- Severe abdominal pain (possible pancreatitis — seek immediate care)
- Vision changes or severe headaches
- Symptoms of thyroid tumor (neck lump, hoarseness, trouble swallowing)
- Symptoms of low blood sugar (shakiness, confusion, rapid heartbeat, sweating)
- Severe allergic reactions (rash, itching, difficulty breathing, swelling)
- Gallbladder pain (upper right abdominal pain, fever, jaundice)
Frequently Asked Questions About GLP-1 Dosing
What is the difference between Semaglutide and Tirzepatide?
Semaglutide (Ozempic, Wegovy) is a GLP-1 receptor agonist, while Tirzepatide (Mounjaro, Zepbound) is a dual GIP/GLP-1 receptor agonist. Tirzepatide typically produces greater weight loss (21% vs 15%) but may have more GI side effects initially. Both require prescriptions and medical supervision.
How do I calculate my Ozempic or Wegovy dose?
Use the Dosing Schedule tab above. Select 'Semaglutide' and your purpose (weight loss or type 2 diabetes). The calculator shows the standard titration schedule: starting at 0.25 mg weekly, increasing every 4 weeks up to 2.4 mg for weight loss (Wegovy) or 2 mg for diabetes (Ozempic). Never exceed your prescribed dose.
What is the Mounjaro and Zepbound dosing schedule?
Mounjaro and Zepbound both contain tirzepatide. The standard schedule starts at 2.5 mg weekly for 4 weeks, then increases to 5 mg, 7.5 mg, 10 mg, 12.5 mg, and finally 15 mg for weight loss. For type 2 diabetes, maintenance is often 5-10 mg. Your doctor may adjust based on tolerance and results.
How do I reconstitute compounded semaglutide or tirzepatide?
Enter your vial size (mg) and reconstitution volume (mL) in the Reconstitution tab. The calculator shows the concentration (mg/mL) and injection volume (mL) needed for your dose. For example, a 5 mg vial with 2 mL bacteriostatic water = 2.5 mg/mL. A 0.5 mg dose would require 0.2 mL injection volume. Always verify with your pharmacist.
What is Retatrutide and how is it dosed?
Retatrutide is a triple agonist (GLP-1/GIP/GCG receptor) currently in clinical trials. Early data shows up to 24% weight loss. Dosing typically starts at 2 mg weekly, increasing to 4 mg, 8 mg, and 12 mg. It is not yet FDA-approved; access is limited to clinical trials.
What is CagriSema and Cagrilintide?
Cagrilintide is an amylin analog that reduces appetite. CagriSema is a combination of cagrilintide and semaglutide being studied for weight loss. Dosing for cagrilintide alone starts at 0.3 mg, increasing to 2.4 mg. Combined CagriSema shows promise for greater weight loss than semaglutide alone.
How long does it take to see weight loss results?
Most people begin seeing weight loss within 4-6 weeks on GLP-1 medications like Ozempic, Wegovy, Mounjaro, or Zepbound. Peak weight loss typically occurs between months 6-12. The medication works gradually by reducing appetite and slowing gastric emptying. Results vary by individual.
Can I use this calculator for compounded GLP-1 medications?
Yes! The reconstitution calculator is especially useful for compounded semaglutide, tirzepatide, and other peptides. Always verify your specific vial concentration and follow your provider's reconstitution instructions exactly. Compounded medications should come from a licensed 503A or 503B pharmacy.
What are common side effects of GLP-1 medications?
The most common side effects are nausea, diarrhea, constipation, and decreased appetite. These typically improve after 4-6 weeks. Starting at a low dose and titrating slowly helps minimize side effects. Injection site reactions, fatigue, and heartburn are also reported. Contact your doctor if side effects are severe.
How do I know when to increase my GLP-1 dose?
Increase doses according to the schedule only if: 1) You've completed the full time at current dose (usually 4 weeks), 2) Side effects are minimal or tolerable, 3) Your healthcare provider approves the increase. Never skip titration steps or increase faster than prescribed.
What is the maximum dose of Ozempic for weight loss?
The maximum FDA-approved dose of semaglutide for weight loss (Wegovy) is 2.4 mg once weekly. For type 2 diabetes (Ozempic), the maximum is 2 mg weekly. Some providers may prescribe lower maintenance doses if results are good and side effects are minimal.
How do I convert tirzepatide mg to units?
Tirzepatide units depend on your vial concentration. After reconstitution, divide your prescribed mg dose by the mg/mL concentration to get mL. If your syringe is marked in units (1 mL = 100 units), multiply mL by 100. For example, 5 mg dose from a 2.5 mg/mL solution = 2 mL = 200 units.
Is testosterone related to GLP-1 medications?
Testosterone is not a GLP-1 medication — it's a hormone used for testosterone replacement therapy (TRT). However, some patients use both GLP-1 medications and testosterone as part of comprehensive metabolic health management. Always discuss hormone therapy with an endocrinologist.
Educational use only. This calculator is not medical advice. GLP-1 medications including semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound), retatrutide, liraglutide, and cagrilintide require a prescription and medical monitoring. Always consult your healthcare provider before starting, adjusting, or stopping any medication.