- Ozempic (semaglutide) is an injectable GLP-1 receptor agonist originally approved for type 2 diabetes, now widely prescribed off-label for weight loss.
- It works by mimicking a natural hormone that reduces appetite, slows digestion, and helps regulate blood sugar.
- Treatment starts at 0.25mg and gradually increases over 8+ weeks. Most weight loss occurs at higher doses (1.0mg–2.0mg).
- Common side effects include nausea, constipation, and decreased appetite — most improve within a few weeks at each dose.
- Tracking your injections, side effects, and weight trends with a companion app helps you and your doctor optimize treatment.
Ozempic is the brand name for semaglutide, an injectable medication made by Novo Nordisk. It belongs to a class of drugs called GLP-1 receptor agonists, which mimic a natural gut hormone (glucagon-like peptide-1) that regulates appetite and blood sugar. The FDA approved Ozempic in 2017 for type 2 diabetes, but it is now widely prescribed off-label for weight management due to its significant effect on appetite and body weight.
Ozempic is not the same as Wegovy, although both contain semaglutide. Wegovy is the version specifically FDA-approved for chronic weight management, available in higher doses (up to 2.4mg). Ozempic's maximum approved dose is 2.0mg, and its primary FDA indication remains diabetes. In practice, many physicians prescribe Ozempic for weight loss when Wegovy is unavailable due to supply shortages.
How Does Ozempic Work?
Semaglutide works through three main mechanisms:
- Appetite reduction. It acts on GLP-1 receptors in the brain that control hunger and satiety. Most patients describe a noticeable decrease in "food noise" — the constant mental chatter about what to eat next. Meals become satisfying sooner, and cravings between meals diminish.
- Slower gastric emptying. Semaglutide slows the rate at which food moves from the stomach to the small intestine. This means you feel full longer after eating. It's also the primary cause of the nausea that many patients experience, especially early in treatment.
- Blood sugar regulation. For diabetic patients, semaglutide stimulates insulin release and suppresses glucagon when blood sugar is high. For non-diabetic patients, this effect is less pronounced but still contributes to more stable energy levels throughout the day.
The medication has a half-life of approximately 7 days, which is why it's dosed as a once-weekly injection. Drug levels build up gradually, reaching steady state after 4-5 weeks at any given dose.
What Is the Dosing Schedule?
Ozempic uses a dose-escalation protocol designed to minimize side effects. You start low and increase gradually, giving your body time to adjust at each level.
| Weeks | Dose | Purpose | What to Expect |
|---|---|---|---|
| 1–4 | 0.25mg | Initiation (not therapeutic) | Mild appetite changes, possible nausea. This dose is for adjustment only. |
| 5–8 | 0.5mg | First therapeutic dose | Noticeable appetite reduction. Nausea may return briefly. Weight loss typically begins. |
| 9–12 | 1.0mg | Standard maintenance | Stronger appetite suppression. Most patients see consistent weight loss at this level. |
| 13+ | 1.0mg–2.0mg | Full therapeutic range | Maximum effect. Doctor may increase to 2.0mg if needed and tolerated. |
What Are the Common Side Effects?
Most side effects are gastrointestinal and related to semaglutide's mechanism of slowing digestion. They are typically most pronounced in the first 1-2 weeks after starting a new dose level and tend to improve as your body adjusts.
Very common (reported by 10%+ of patients)
- Nausea — The most frequently reported side effect. Usually worst on days 1-3 after injection and fades as the week progresses. Eating smaller meals helps significantly.
- Decreased appetite — This is both a side effect and the intended mechanism. It's more intense at higher doses.
- Diarrhea or constipation — GI changes are common, especially during dose escalation. Staying hydrated and eating fiber-rich foods can help.
Common (reported by 1-10%)
- Abdominal pain — Usually mild. Eating slowly and avoiding very fatty meals helps.
- Fatigue — Some patients report low energy, particularly in the first few weeks. This often improves as your body adjusts to eating less.
- Injection site reactions — Redness, bruising, or itching at the injection site. Rotating injection locations reduces this.
For a deeper look at managing side effects throughout your first month, see our guide on GLP-1 side effects: what to expect.
How Much Weight Can You Expect to Lose?
In clinical trials, patients taking semaglutide 2.4mg (the Wegovy dose) alongside lifestyle interventions lost an average of 14.9% of their body weight over 68 weeks, compared to 2.4% for placebo. At the Ozempic-range dose of 1.0mg, weight loss is typically 10-12% of body weight.
Individual results vary widely. Some patients lose 20%+ of their body weight; others lose 5-8%. Factors that influence results include starting weight, dose tolerance, dietary changes, physical activity, and — critically — behavioral consistency.
Weight loss is not linear. You may lose rapidly in the first 3-4 months, plateau for a few weeks, then resume losing. This is normal. The overall trend over months is what matters, not any individual week.
How to Track Your Ozempic Treatment
Tracking your treatment helps you see patterns, communicate effectively with your doctor, and stay motivated through the inevitable ups and downs. Here's what to track:
- Every injection. Date, time, dose, and injection site. This creates your treatment timeline and ensures you never miss or double a dose.
- Side effects. Note what you feel and when. "Nausea on days 1-2 after injection" is exactly the kind of pattern your doctor needs to hear.
- Weight. Weigh yourself at the same time each day (morning, after bathroom, before eating). An app that shows the trend line rather than daily fluctuations gives you the real picture.
- Meals. You don't need to count calories. Simply checking in on whether your meals were supportive helps you build the eating habits that sustain your results. (Learn more about weight loss without counting calories.)
- How you feel. A brief daily reflection — energy level, mood, appetite — builds self-awareness and creates a record you can share with your healthcare provider.
A GLP-1 companion app like MyWhy combines all of this in one place: injection tracking, drug-level visualization, meal check-ins, weight trends, and daily reflections — all free. For a comparison of tracking options, see our best free GLP-1 tracking apps guide.