After your first dose of Wegovy, you may notice changes in your appetite within a few days, or you may feel nothing at all. The starting dose is intentionally low, at 0.25 mg, designed to let your body adjust rather than produce dramatic results right away. Most people spend the first week or two paying close attention to every sensation, so here’s a realistic picture of what the first dose actually looks like.
How Quickly It Starts Working
Wegovy reaches its peak activity in your body about 72 hours after injection. The medication mimics a gut hormone that signals fullness to your brain and slows how fast food leaves your stomach. Some people feel a subtle shift in appetite within those first few days. Others notice nothing until the dose increases weeks later.
This is normal and doesn’t mean the medication isn’t working for you. As one Cleveland Clinic obesity medicine specialist explains, the initial dose may not produce any noticeable effect on appetite. You may need to move through several dose increases before you feel a real difference. The 0.25 mg starting phase lasts four weeks, and its primary purpose is to ease your body into tolerating the drug, not to suppress your appetite aggressively.
Common Side Effects in the First Week
The most frequently reported side effects are gastrointestinal: nausea, diarrhea, constipation, and occasional vomiting. Nausea is by far the most common complaint and tends to peak in the first few days after injection before fading. At the 0.25 mg dose, these symptoms are generally mild. Many people describe it as a low-grade queasiness rather than the kind of nausea that keeps you in bed.
You might also notice mild bloating, gas, or a vague feeling of fullness even when you haven’t eaten much. Some people get a headache or feel more tired than usual. These effects typically improve within the first week or two as your body adjusts. If nausea hits you hard, it tends to be worst after the first injection and less intense with subsequent weekly doses at the same level.
What to Eat and Drink
Staying hydrated matters more on Wegovy than you might expect. Nausea, diarrhea, and vomiting can all pull fluid from your body, and dehydration can stress your kidneys. Women should aim for at least 9 cups of water daily, and men at least 13 cups. If you’re experiencing GI side effects, you likely need more than that baseline.
Smaller, more frequent meals tend to sit better than large ones, especially while your stomach is emptying more slowly. Bland, low-fat foods are easier to tolerate if nausea is an issue. Greasy, heavy, or very rich meals are the most common triggers for feeling worse. Keep crackers, toast, or plain rice on hand for the first few days. Carbonated water or ginger tea can help settle mild queasiness.
Some practical hydration tips that help: keep a water bottle with you throughout the day, drink water alongside every meal, and try adding lemon or cucumber if plain water feels unappealing. Spacing most of your water intake before late afternoon can help you avoid waking up at night.
How Much Weight to Expect
Clinical trials found that people lost an average of about 2% of their starting body weight during the first four weeks. For someone starting at 200 pounds, that works out to roughly 4 pounds. Some people lose more, some lose less, and some don’t see any change on the scale during the first month.
This is the lowest dose in a five-step titration schedule that gradually increases over several months. Meaningful weight loss typically builds as the dose goes up. Setting expectations around 2% in month one helps avoid the frustration of comparing your results to the headline numbers from clinical trials, which reflect outcomes at the full maintenance dose after more than a year of treatment.
Giving Yourself the Injection
Wegovy comes in a prefilled, single-use pen with a hidden needle, so you never see the needle itself. You inject it once a week, on the same day each week, at any time of day, with or without food. The three recommended injection sites are the front of your thighs, your stomach (at least two inches from your belly button), and the upper arms. Rotating between these areas helps prevent skin irritation at any one spot.
Store your pen in the refrigerator between 36°F and 46°F. If you need to carry it with you, it can stay at room temperature (up to 86°F) for up to 28 days as long as you keep it in the original carton. Never freeze the pen. Taking it out of the fridge about 30 minutes before injecting can make the injection more comfortable, since cold medication sometimes stings slightly.
Symptoms That Need Attention
Mild nausea and digestive discomfort are expected. Severe symptoms are not. Contact your prescriber if you experience severe stomach pain that radiates to your back, because this can signal pancreatic inflammation. Persistent, intense vomiting that doesn’t let up is another reason to call.
Gallbladder problems are a known risk with this class of medication. Warning signs include pain in the upper right area of your abdomen, pain between your shoulder blades, yellowing of your skin or eyes, fever with chills, dark urine, or pale clay-colored stools. These symptoms are uncommon, especially at the starting dose, but knowing what to watch for puts you in a better position to act quickly if something feels off.
What the First Month Looks Like
You’ll stay on 0.25 mg for four full weeks before your prescriber moves you to the next dose level. During this time, the main goal is tolerability. Some weeks you may barely notice you took anything. Other weeks, mild nausea might show up a day or two after your injection and then fade. Your appetite may dip slightly, or it may stay exactly the same.
The experience varies widely from person to person. People who feel very little at 0.25 mg sometimes worry the medication won’t work for them, but this dose is simply the on-ramp. Each subsequent dose increase (which happens roughly every four weeks) brings a stronger effect on appetite and, for many people, a fresh but temporary wave of GI adjustment. By the time you reach the maintenance dose months later, your body has had time to adapt gradually, which is exactly why the process is designed to start this low.