Person standing on bathroom scale while wondering how fast semaglutide works for weight loss

How Fast Does Semaglutide Work for Weight Loss?

Written on August 21, 2023 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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Starting a weight loss journey is challenging, but it can also be exciting! Part of the excitement could be when you begin to see your numbers drop or your clothes start to fit a little more loosely. How quickly you begin to lose weight can impact your continued enthusiasm. If you wonder how fast semaglutide works for weight loss, continue reading. This article will share more on semaglutide, how it works, and safety information for the medication.

What Is Semaglutide?

Semaglutide is a medication that can be used to treat type 2 diabetic patients and chronic weight loss in obese and overweight people.[1] The brand name of semaglutide used for weight loss is Wegovy®, which has a higher dose than used for type 2 diabetes. Semaglutide belongs to a class of drugs called GLP-1s, or glucagon-like peptide 1 agonists.[2,3] Semaglutide is the first GLP-1 drug approved by the U.S. Food and Drug Administration (FDA) for weight loss in obese and overweight individuals.[2] Semaglutide is used in combination with diet and exercise for weight loss.[1]

GLP-1s are also referred to as GLP-1 analogs and incretin mimetics.[3] GLP-1s, including semaglutide, are essentially manufactured forms of the human GLP1 hormone.[1] GLP-1 is an incretin hormone released in the gastrointestinal tract as a response to the foods you consume. Semaglutide is highly similar (94% sequence homology) to the human form of GLP1.[1,2]

How Semaglutide Works

Semaglutide works by imitating the GLP-1 that is naturally released in your body.[2] GLP-1 can improve metabolism, control glucose levels by stimulating insulin release, and promote weight loss. The exact and complete mechanism of how GLP-1 works is still unclear.[2] GLP-1 is proposed to reduce weight by delaying gastric emptying and reducing food intake.[2] Semaglutide also impacts pathways in the brain that regulates appetite and food intake.[1]

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How Fast Does Semaglutide Work For Weight Loss?

How fast semaglutide works for weight loss will vary with each person. Semaglutide reaches the maximum concentration in the body in one to three days after receiving a dose.[1] In the STEP clinical trials, patients on semaglutide reported weight loss within a few weeks of starting treatment.[1,4] The STEP 1 study included 1961 adult participants who were obese or overweight and had at least one weight-related condition.[4] Participants were randomly assigned to semaglutide or placebo with diet and exercise for 68 weeks. Weight loss was observed during the first assessment after randomization at week four.

Understanding Dosing And Administration Of Semaglutide

The dosing for semaglutide requires an initial dose of 0.25 mg once a week for four weeks.[1] Every four weeks after this, the dose is increased until 2.4 mg is reached. The maintenance dose is 2.4 mg once weekly for adults. If you don’t tolerate the increase in doses due to experiencing side effects, your healthcare provider may delay the dose escalation for another four weeks. You may have to stop the medication if you cannot tolerate the target dose.

Semaglutide is administered once weekly on the same day each week.[1] It can be given at any time of the day, with or without meals. If you miss your dose and the next scheduled dose is more than two days away, go ahead and administer the dose as soon as you can. If your missed dose is less than two days away from your next scheduled dose, then skip the dose and resume on the regularly scheduled day of the week.

Semaglutide Safety Information

The most common side effects of semaglutide are nausea, diarrhea, and vomiting.[1,2] Other frequent side effects include headache, fatigue, upset stomach, dizziness, belching, abdominal distention, hypoglycemia in type 2 diabetes, and flatulence. Semaglutide also has more serious FDA safety warnings for potential thyroid C-cell tumors. [1] Other safety considerations include acute gallbladder disease, hypoglycemia, acute kidney injury, eye complications in type 2 diabetics, increased heart rate, and hypersensitivity reactions. If you have a known hypersensitivity to semaglutide, you should avoid use.

How To Get Semaglutide

You will need a prescription from a healthcare provider to get semaglutide.[1] They will determine if semaglutide is appropriate for you. Via Everlywell, you can schedule a virtual visit with a licensed healthcare provider through a comprehensive telehealth option for weight loss help online. You will have regular one-on-one meetings with a clinician, receive support for related health conditions, and get access to GLP-1 prescriptions if you qualify.

When Does Semaglutide Start Working For Weight Loss?

How Much Weight Can You Lose On Semaglutide?

How to Keep the Weight Off After Semaglutide


  1. DailyMed - Wegovy®- semaglutide injection, solution. U.S. National Library of Medicine. Accessed August 14, 2023.
  2. Alorfi NM, Algarni AS. Clinical impact of semaglutide, a glucagon-like peptide-1 receptor agonist, on obesity management: A review. Clin Pharmacol. 2022;14:61-67. doi: 10.2147/CPAA.S374741
  3. Collins L, Costello RA. Glucagon-like peptide-1 receptor agonists. [Updated 2023 Jan 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023. Available from:
  4. Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. doi: 10.1056/NEJMoa2032183
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