The standard test is simple: losing more than 5% of your body weight after about 3 months on your treatment dose. This guide explains how to judge your progress, when to talk to your prescriber, and what to do if you miss a dose.
How do I know whether my GLP-1 dose is working?
- The main benchmark: more than 5% weight loss after about 3 months on your treatment dose. For someone weighing 220 lb, that is 11 lb or more. People who reach this should generally stay on treatment long-term, per the American Diabetes Association's 2026 standards (1, 2).
- What to expect over time: weight comes off fastest in the first 6 months and levels off around 18 months (3).
- Typical totals: in clinical trials, people on full-dose semaglutide or tirzepatide lost about 15% to 21% of their body weight on average. In everyday practice, results are lower, about 8% to 11% after 60 weeks on semaglutide (3).
- Other signs it is working: better blood sugar, blood pressure and cholesterol, less "food noise" (constant thoughts about food), and a smaller waist.
- How often to check in: at least monthly for the first 3 months, then at least every 3 months after that (2).
When should I talk to my prescriber about raising or changing my dose?
Bring any of these to your prescriber:
- Less than 5% weight loss after 3 months on the highest dose you can tolerate. Your prescriber will review how consistently you take it, your dose, side effects and other options. One example is switching from semaglutide to tirzepatide (1, 2).
- A plateau before you reach your goals. The American Diabetes Association warns against simply staying the course when progress stalls. Your plan should be reviewed, and may add or change treatment: another medication, surgery, or a structured lifestyle program (2).
- Side effects you can't tolerate. Raising the dose more slowly or staying on a lower dose is acceptable. Your right dose may be below the highest approved dose (2, 4).
- Weight loss that seems too fast, such as more than 5% in one month, or signs you are losing muscle or strength (1).
- You also take insulin or a sulfonylurea (such as glipizide or glyburide). These often need to be adjusted to prevent low blood sugar (2).
- You missed two or more doses in a row, or you are thinking of stopping. See the next section, and our guide on keeping weight off after treatment.
What happens if I miss an injection?
The rules depend on which medication you take:
| Medication | What to do if you miss a dose | Reference |
|---|---|---|
| Wegovy injection (semaglutide) | If your next dose is more than 2 days (48 hours) away, take the missed dose as soon as you can. If it is less than 2 days away, skip it and take your next dose on your usual day. | 4 |
| Wegovy tablets (semaglutide) | Skip the missed dose and take the next one the following day. Never take two tablets in one day. | 4 |
| Zepbound or Mounjaro (tirzepatide) | Take the missed dose if it is within 4 days (96 hours) of when it was due. If it is later than that, skip it. Doses must always be at least 3 days (72 hours) apart. | 5 |
- Missed two or more Wegovy injections in a row? The label says to restart at a lower dose to reduce stomach side effects. Your prescriber decides this, so call before your next dose (4).
- One missed dose is not a big deal. Modeling studies suggest a single missed dose has little effect on weight loss. Semaglutide stays in your body longer than tirzepatide, which gives a bit more buffer (6, 7).
- Several missed doses matter more. Restarting at your full dose after a gap can cause more nausea and vomiting. Check with your prescriber first (6, 7).
This guide is for education only. Talk with your prescriber before changing or stopping your medication.
References
- Moiz A, Peters TM, Tsoukas MA, et al. Balancing the benefits and risks of GLP-1 receptor agonists: a clinical guide for shared decision-making. EClinicalMedicine. 2026.
- American Diabetes Association Professional Practice Committee for Diabetes. 8. Obesity and weight management for the prevention and treatment of diabetes: Standards of Care in Diabetes–2026. Diabetes Care. 2026.
- Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society. The American Journal of Clinical Nutrition. 2025.
- Wegovy (semaglutide). FDA drug label. Food and Drug Administration. Updated June 18, 2026.
- Apovian CM, Aronne L, Barenbaum SR, et al. Clinical Management of Obesity, Third Edition. The Obesity Society. 2025.
- Overgaard RV, Agersø H, Hollensen C, Rathor N, Bomberg EM. The impact of missed doses on pharmacokinetic concentrations for oral semaglutide in comparison to other glucagon-like peptide-1-based therapies. Diabetes, Obesity & Metabolism. 2026.
- Cengiz A, Wu CC, Lawley SD. Incretin mimetics for weight loss forgive nonadherence. Diabetes, Obesity & Metabolism. 2025.
