Getting started with Wegovy

Wegovy is the brand name for semaglutide. It’s part of a group of medicines called GLP-1 receptor agonists. It works like a natural hormone your gut makes after eating: it signals your brain that you’ve had enough and slows how quickly your stomach empties. The result is that you tend to feel full sooner and stay satisfied longer, so you eat less.

It’s prescribed for long-term weight management in adults who have obesity, or who are overweight and have a weight-related health condition, and for some people age 12 and older. It’s meant to be used together with a reduced-calorie eating plan and increased physical activity — not on its own. Wegovy is also used in certain people to lower the risk of heart problems and to treat a form of liver disease; your care team can explain if either applies to you.

Wegovy comes as a prefilled, single-dose pen that you inject just under the skin once a week. Take it on the same day each week, at any time of day, with or without food. Use one pen per dose.

Where to inject

Inject into your abdomen (belly), thigh, or upper arm. Rotate where you inject — pick a different spot each week to keep the skin healthy. You can change your injection site without changing your dose.

Changing your day

If you need to move your weekly dose to a different day, that’s okay as long as it has been at least 2 days (48 hours) since your last dose. Follow your care team’s directions.

Before each injection

Look at the liquid in the pen. Use it only if it’s clear and colorless. Don’t use a pen if the liquid looks cloudy or has particles in it.

Your dose over time

You’ll usually start low and your dose increases gradually over time, exactly as your prescriber directs. Don’t change your dose on your own or use Wegovy with any other GLP-1 medicine.

Storing your pens

• Keep pens in the refrigerator at 36–46°F (2–8°C), in the original carton to protect them from light.
• Do not freeze. Don’t use a pen that has been frozen.
• If needed, an unused pen can be kept at room temperature (up to 86°F / 30°C) for up to 28 days.
• Each pen is for a single use. After injecting, throw it away in a sharps container — not the household trash.

If you miss a dose

• If your next dose is more than 2 days away, take the missed dose as soon as you remember.
• If your next dose is 2 days or less away, skip the missed dose and take your next one on your regular day.
• If you’ve missed two or more doses in a row, contact your care team before your next dose.

Weight change usually begins in the first weeks and builds gradually as your dose increases, with most of the change happening over the first several months to about a year. In the STEP 1 (Novo Nordisk) trial, adults using Wegovy together with a reduced-calorie diet and more activity lost about 15% of their starting weight on average. Results vary from person to person.

Wegovy is a long-term medicine. If you stop, appetite tends to come back and weight is often regained — in studies, people regained about two-thirds of the weight they had lost within a year of stopping. That’s expected with the condition, not a personal failure.

The most common side effects are stomach-related, especially in the first few months while your dose is increasing. About 4 in 10 people feel nausea early on; other common effects include diarrhea, vomiting, constipation, and stomach pain. These are usually mild to moderate and tend to settle as your body adjusts. Tell your care team about anything that bothers you — there are ways to help.

Easing stomach side effects

• Nausea: eat smaller meals, eat slowly, and stop when you feel full. Avoid greasy, fried, spicy, and very sweet foods. Limit alcohol and fizzy drinks. Ginger or peppermint tea may help.
• Constipation: aim for enough fiber and fluids and gentle daily movement. Ask your care team about a stool softener or laxative if you need one.
• Diarrhea: avoid large, high-fat meals; ask about anti-diarrheal options for short-term relief.
• Heartburn: eat smaller portions and avoid lying down for a few hours after eating.

Protect your muscle and nutrition

When you lose weight, some of it can come from muscle. To help protect it:

• Eat enough protein — about a palm-sized portion at each meal.
• Do strength exercises 2–3 times a week, plus regular activity like brisk walking.
• Stay hydrated. Wegovy can reduce your sense of thirst, so drink water regularly even when you don’t feel thirsty.
• Ask your care team whether vitamin D, calcium, B12, or a daily multivitamin would help.

A small number of people notice temporary hair thinning, which usually improves over time.

Don’t use Wegovy if

• You or a family member has had medullary thyroid cancer (MTC) or MEN 2.
• You’ve had a serious allergic reaction to semaglutide.
• You’re already taking another GLP-1 medicine or another semaglutide product.

Tell your care team about your other medicines

Because Wegovy slows how fast your stomach empties, it can affect how some pills are absorbed. Share a full list of what you take. If you use insulin or a sulfonylurea for diabetes, your blood sugar can drop too low — your care team may adjust those medicines.

Birth control and pregnancy

Wegovy may harm a developing baby, so use reliable birth control while taking it. Because the medicine stays in your body for weeks, stop at least 2 months before trying to become pregnant. Tell your care team right away if you become pregnant or are planning to. Weight loss can also make pregnancy more likely for some people, so contraception matters even if pregnancy was hard before.

Surgery, procedures, and anesthesia

Because Wegovy slows stomach emptying, tell every doctor, dentist, surgeon, and anesthesia provider that you take it before any procedure that uses sedation or anesthesia. Recommendations on this vary, so follow the specific instructions your care team gives you for preparing.

Other things to be aware of

Gallbladder problems can happen, especially with rapid weight loss. Rarely, the pancreas can become inflamed. Dehydration from vomiting or diarrhea can affect your kidneys. The next section explains the warning signs and what to do.