Wegovy is a popular weight loss treatment. Clinical trials have shown to help people lose up to 15% of their body weight in a year. [1] Like any medication, some people taking Wegovy will experience side effects. But is tiredness directly linked to this treatment? We’ve asked our clinical experts to explain if there’s evidence to back it up, below.
Wegovy works for weight loss because it helps reduce the appetite and slows down stomach emptying, causing you to eat less and feel fuller for longer. It is a glucagon-like peptide-1 (GLP-1) receptor agonist, which means it mimics the body’s GLP-1 hormone, acting in several areas in the brain to regulate appetite. Like Ozempic, Wegovy uses semaglutide as its active ingredient and is taken as a weekly injection. [2]
Not everyone taking Wegovy will experience all or any adverse effects. For those that do, they are usually mild side effects which go away after a few weeks once your body adjusts to the medication. [3] Six most common side effects are [2]:
Other less common side effects of Wegovy include hair loss, increased heart rate and bloating. [4]
One of the main benefits of GLP-1 medications for weight management is that they reduce appetite. This means you’ll naturally consume less calories (the measurement of energy in a food or drink) from your diet. While we recommend eating in a calorie deficit throughout your weight loss journey, not eating enough calories could cause you to experience fatigue – as well as potentially slow down your metabolism. You can read more on how to calculate your calorie deficit here.
Tiredness is also one of the symptoms of dehydration, which can occur if you experience gastrointestinal side-effects like vomiting and diarrhoea. [5] It’s important to stay well hydrated by drinking plenty of fluids and – when necessary – electrolytes throughout your Wegovy treatment. You can also up your water intake by eating foods that are low in calories but high in water content, like fruits and vegetables. Think about snacking on grapefruit (which is about 90% water) or raw carrots about 88% water). [6]
The manufacturers of Wegovy recommend keeping detailed notes (in a journal or your phone) of any side effects you experience, so that you can share as much information as possible with your Levity clinical team or healthcare provider. If you’re noticing stints of tiredness, take note of when it started, how long it lasted, and how often it has happened. [7] They’ll then recommend some tactics to manage your fatigue, which may include:
It’s worth remembering that side effects are felt most intensely at the beginning of treatment, and after each dosage increase, while the body adjusts. This is perfectly normal, and they will usually improve within weeks. If they don’t, and you continue to feel tired or lethargic – or it’s impacting your life in a negative way – it’s important to speak to your clinical team here at Levity so we can help you manage your side effects safely, while still working towards your weight loss goals. We’re here to support you every step of the way.
If you haven’t yet started weight loss medication and want to find the right treatment for you, you can visit our website here.
1. Wilding JPH, Batterham RL, Calanna S. Once-Weekly Semaglutide in Adults with Overweight or Obesity. The New England Journal of Medicine [Internet]. 2021 Feb 10;384(11):989–1002. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2032183
2. Wegovy (semaglutide) Information for Patients [Internet]. Drugs.com. Available from: https://www.drugs.com/wegovy.html
3. Godman H. Questions and answers about the new anti-obesity medications [Internet]. Harvard Health. 2024. Available from: https://www.health.harvard.edu/staying-healthy/questions-and-answers-about-the-new-anti-obesity-medications
4. Ghusn W, De la Rosa A, Sacoto D, Cifuentes L, Campos A, Feris F, et al. Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity. JAMA Network Open [Internet]. 2022 Sep 19;5(9):e2231982. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9486455/
5. MHRA. GLP-1 receptor agonists: reminder of the potential side effects and to be aware of the potential for misuse [Internet]. GOV.UK. 2024. Available from: https://www.gov.uk/drug-safety-update/glp-1-receptor-agonists-reminder-of-the-potential-side-effects-and-to-be-aware-of-the-potential-for-misuse
6. Mayo Clinic. The Simple Math That Helps You Feel Full on Fewer Calories [Internet]. Mayo Clinic. 2017. Available from: https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/weight-loss/art-20044318
7. Tips for managing common side effects [Internet]. Wegovy.com. 2024 [cited 2025 Mar 7]. Available from: https://www.wegovy.com/dashboard/my-library/week-02-tips-for-managing-common-side-effects.html#anchor-article-2
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