Ozempic, Wegovy, Mounjaro, Zepbound, and Trulicity. What is the difference?
These five medicines are weekly injections in the GLP-1 family, but they are not interchangeable. This guide explains what is in each one, what each is approved for, and the one rule that matters most: never switch a brand or copy a dose without a new prescription and a pharmacist check.
This guide is here to teach you. It is not medical advice, and it does not replace your doctor or pharmacist. Always do what your doctor tells you, and ask a pharmacist before you change how you take any medicine.
Print this guide for your fridgeYour 60 second GLP-1 safety checklist
- These medicines are not interchangeable.Some contain semaglutide, some tirzepatide, and one dulaglutide. Their approved uses, strengths, pens, and dose steps all differ.
- Never switch a brand or copy a dose on your own.A safe switch needs a new prescription and a pharmacist check. A number on one pen is not a conversion for another.
- Know your missed dose window.Each brand has its own rule. Ozempic injection is within 5 days. Mounjaro and Zepbound are within 4 days. The windows are not the same.
- Do not count pen clicks.Use only the labeled dose selector and the Instructions for Use for your exact product. Do not use online click charts.
- Tell the surgery team.These medicines slow stomach emptying. Give the exact product, schedule, and last dose before any anesthesia or sedation.
- Do not combine GLP-1 medicines.Using two together, or duplicate semaglutide or tirzepatide products, is generally not recommended.
What these medicines are and how they differ
All five are once weekly injections in the GLP-1 family. But they do not all contain the same medicine, and they are not approved for the same things.
Here is the landscape, brand by brand.
- Ozempic (semaglutide). Approved for type 2 diabetes and to reduce major cardiovascular events in certain adults. The injection label also includes reduction of certain kidney and cardiovascular outcomes in adults with type 2 diabetes and chronic kidney disease.
- Wegovy (semaglutide). Approved for long term weight reduction in eligible patients and cardiovascular risk reduction in certain adults. Current labeling also includes uses that are specific to the dosage form.
- Mounjaro (tirzepatide). Approved for type 2 diabetes.
- Zepbound (tirzepatide). Approved for long term weight reduction in eligible patients, and for moderate to severe obstructive sleep apnea in adults with obesity.
- Trulicity (dulaglutide). Approved for type 2 diabetes and cardiovascular risk reduction in certain adults with type 2 diabetes.
The simple version: Ozempic and Wegovy both contain semaglutide. Mounjaro and Zepbound both contain tirzepatide. Trulicity contains dulaglutide. Same ingredient does not mean same brand. The pens, strengths, approved uses, dose steps, and insurance rules are not interchangeable.
Same family, different rules
Because two brands can share an ingredient, patients often assume they can move between them. They cannot. Do not transfer units, clicks, milligrams, or a maintenance dose from one brand to another.
Food rules also differ by form. The weekly injections may be taken with or without meals. Current Ozempic and Wegovy tablets are different: they are taken in the morning on an empty stomach with plain water only, followed by at least a 30 minute wait before food, drinks, or other oral medicines. Always identify the brand and dosage form before following any instruction.
Insurance follows the approved use. A plan may cover a diabetes brand but not a weight management brand even when the active ingredient is related. Coverage depends on your diagnosis, your plan formulary, prior authorization rules, step requirements, and current supply.
Why you should not switch brands or doses on your own
A number on one pen is not a conversion instruction for another pen. Starting too high can cause severe stomach symptoms and dehydration. Using the wrong insulin or diabetes combination can cause dangerous glucose changes.
A safe switch requires a new prescription, confirmation of your last dose and how you tolerated it, a review of the reason for treatment, and counseling on the new device and its missed dose rule. If your pharmacy is out of stock, ask the prescriber and pharmacist. A shortage does not create an automatic dose conversion.
This page will not tell you what dose to take. Your prescriber picks the product and dose for your indication, and your pharmacist checks it. If you are not sure your product or dose is right, ask us. That is exactly the kind of question we answer at Fairview.
Missed dose rules, brand by brand
All five injections are taken once weekly. The weekly injections may be taken with or without food, any time of day. The missed dose windows are not the same, so use the rule for your exact brand.
If you miss a dose:
- Ozempic injection: take it within 5 days of the missed dose. After that, skip it. The tablets follow a different rule: skip and resume the next day.
- Wegovy injection: take it if the next dose is more than 48 hours away. Otherwise skip. Ask about restarting after 2 or more missed doses. Tablets: skip and resume the next day.
- Mounjaro: take it within 4 days. After that, skip. Keep 72 hours between doses.
- Zepbound: take it within 4 days. After that, skip. Keep 72 hours between doses.
- Trulicity: take it only if at least 72 hours remain before the next dose. Otherwise skip.
- If you are not sure what to do, call Fairview at 601-544-4871.
What these medicines share, and when to get help
Common with all of them. Often improves with time.
- Nausea, vomiting, diarrhea, constipation, stomach discomfort, indigestion, and reduced appetite.
- Injection site reactions.
- Smaller meals, slower eating, and steady fluids may help.
Call your doctor or pharmacist if you notice:
- Stomach symptoms that are severe, persistent, worsening, or prevent you from drinking fluids.
- Low blood sugar, which is more likely when these medicines are combined with insulin or a sulfonylurea.
- Signs of dehydration, like dizziness or reduced urination.
Call 911 or get urgent help if you have:
- Trouble breathing, face or throat swelling, fainting, loss of consciousness, or a seizure.
- Severe low blood sugar when the person cannot swallow safely.
- Severe, steady abdominal pain that may reach the back, especially with vomiting. This may be pancreatitis.
- Severe dehydration or inability to keep fluids down.
What to be careful with
Low blood sugar is more likely when any of these medicines is combined with insulin or a sulfonylurea. Tell your pharmacist about every diabetes medicine you take.
Alcohol can worsen nausea, dehydration, or glucose changes. Ask your care team what is right for you.
Pregnancy needs a plan. Weight loss treatment should not be used during pregnancy. Semaglutide products are generally stopped at least 2 months before a planned pregnancy. Tirzepatide can reduce the effectiveness of oral hormonal birth control for 4 weeks after starting and for 4 weeks after every dose increase, so use a non oral method or add a barrier method during those periods. Diabetes during pregnancy still needs active treatment, so the clinician must make a replacement plan. Do not stop on your own.
Compounded products are not the same. Compounded drugs are not FDA approved and are not FDA approved generic versions of these brands.
Before you start, stop, or change any medicine or supplement, tell your pharmacist which GLP-1 medicine you take. Every single time.
What it costs
The cost is different for every person, because every insurance plan is different.
Here is the honest way to find your price. If you pay cash, call Fairview and we will give you a price for your situation. If you have private insurance, there may be a coupon or a savings program from the maker of the drug that helps lower your cost, and we will check if one is available for you. The best step is to let a pharmacist look at your plan. We do this for every patient.
Do not let cost make you skip doses. Call us first. There is almost always something we can do.
Availability and insurance coverage can change. Fairview will check whether an FDA approved lower cost alternative, a manufacturer savings program, an insurance exception, or another cost saving option is available for your specific prescription.
What should be checked
These medicines share warning signs, but each patient needs an individual plan. Here is what your care team should keep an eye on.
Your doctor should check, now and then:
- Your glucose control, if you take one of these for diabetes.
- Stomach symptoms that are severe, persistent, or worsening.
- Your pregnancy plans, so treatment can be adjusted safely.
- Whether your product still matches your diagnosis and goals.
Your pharmacist should, now and then:
- Confirm your exact brand, dosage form, and dose at every fill.
- Check your other medicines, especially insulin and sulfonylureas.
- Review your missed dose rule, since it differs by brand.
- Check formulary status, prior authorization, refill timing, and approved alternatives when appropriate.
At Fairview, we can review the actual prescription, package, device, dose, insurance requirements, and other medicines with you. Contact us before switching, converting a dose, or using a product you do not recognize.
Special situations
Before surgery or anesthesia.
These medicines can delay stomach emptying. Food or liquid left in the stomach may enter the lungs during general anesthesia or deep sedation. Tell the surgeon, the anesthesia professional, and the procedure clinic the exact product, dosage form, schedule, and last dose. Follow their individualized fasting and medication plan. Do not use a holding schedule from social media or decide on your own when to restart.
Pregnancy and pregnancy planning.
Weight loss treatment should not be used during pregnancy. Semaglutide products are generally stopped at least 2 months before a planned pregnancy. Tirzepatide affects oral hormonal birth control for 4 weeks after starting and after every dose increase. The responsible clinician must make the plan. Do not stop diabetes treatment without guidance.
If your pharmacy is out of stock.
Ask the prescriber and pharmacist before doing anything. A shortage does not create an automatic dose conversion, and a compounded product is not an FDA approved substitute for these brands.
Insurance and coverage.
Coverage commonly follows the FDA approved use, your diagnosis, the plan formulary, prior authorization rules, step requirements, and current supply. Fairview can check current coverage and approved alternatives, but we cannot promise a price, coupon, substitution, or approval.
How Fairview helps patients on these medicines
Products that sound similar may have different approved uses, strengths, timing rules, and storage. That is why personalized counseling matters.
Before you start or switch:
- We review the actual prescription, package, device, and dose with you.
- We confirm your last dose and tolerance before any change.
- We counsel you on the new device and its missed dose rule.
For insurance and cost:
- We check formulary status and prior authorization requirements.
- We check refill timing and current savings options.
- We look at approved alternatives when appropriate.
Any time you are unsure:
- Contact us before switching, converting a dose, or using a product you do not recognize.
- Ask Dr. Mike a question through our website, or call 601-544-4871.
Questions patients ask about these weekly medicines
There is no safe strongest ranking for an individual. The right medicine depends on the approved use, your health history, your other medicines, your tolerance, your coverage, and your treatment goals.
Related guides
Have a question about these weekly medicines?
Fairview can review the actual prescription, package, device, dose, insurance requirements, and other medicines with you. Products that sound similar may have different approved uses, strengths, timing rules, and storage. Contact us before switching, converting a dose, or using a product you do not recognize. Moving your prescription to us takes one phone call.