Key takeaways
- Most people start with a low dose of GLP-1s for weight loss. They are typically given as a once-weekly injection.
- Major weight loss most likely will not occur in the first week of treatment with a GLP-1.
- Side effects are common in the first week of treatment as your body adjusts to the medication.
GLP-1 medications are increasingly used to support weight loss. A few examples include Wegovy (semaglutide) and Zepbound (tirzepatide). While these drugs can be very effective, the first week is often a time of adjustment as your body gets used to the medication.
Keep reading to learn more about what to expect during your first week of using a GLP-1.
Note: This article focuses on injectable GLP-1s, which are the most commonly prescribed form for weight loss. An oral tablet version of Wegovy (semaglutide) was recently approved for weight loss. However, it may have different instructions and side effects than those covered here.
GLP-1s for weight loss are typically given as a once-weekly injection. Most people start with a low dose to help minimize side effects and give the body time to adjust.
You’ll inject the drug under the skin of your abdomen, thigh, or upper arm. Your healthcare provider or pharmacist can show you how to give yourself the injection. You can also look on the manufacturer website for instructions or videos.
Wegovy, a GLP-1 medication used for weight loss, is now also available as an oral tablet that you take by mouth once per day. Talk with your doctor to see which GLP-1 is best for you.
In the first week, the main goal is to help your body tolerate the medication. Your doctor will likely increase your dose slowly over the following weeks, depending on how your body responds.
How much weight can you lose in the first week?
Most people do not experience major weight loss in the first week after starting a GLP-1.
Some people may lose a few pounds in the first week due to a reduced appetite or smaller portion sizes. However, lasting results typically happen gradually over several months of consistent use and healthy lifestyle changes.
Side effects are common in the first week of GLP-1 treatment as your body adjusts to the drug. For many people, these symptoms are mild and temporary.
Common side effects include nausea or vomiting, constipation, bloating, diarrhea, and low energy. Eating smaller meals and limiting greasy foods may help ease discomfort. Increasing fiber intake and fluid intake can also help prevent constipation.
If side effects are severe or do not improve, talk with your doctor. They may adjust your dose or recommend other strategies to help.
During your first few weeks of GLP-1 treatment, stay in contact with your doctor. They’ll monitor how your body is responding to the drug and make any needed changes.
As you continue treatment, keep track of how you’re feeling and any side effects. This information can help your doctor personalize your treatment and support your overall care.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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