Home Weight Loss Injections: Options, Safety And Effectiveness

There are already multiple weight loss injections to choose from. So how do you know which is the best injection for weight loss at home, and whether it’s right for your needs?

Here’s our expert guide to help you understand and compare your options, to make sure you find the best weight loss medication for you.

Article Summary:

• Weight loss injections, such as GLP-1 based treatments, agonists are self-injectable medications used for weight loss and type 2 diabetes. They mimic naturally occurring gut hormones involved in appetite regulation and blood sugar control.
• Mounjaro and Wegovy are two of the most popular options. But there are different medications to choose from based on your health and weight loss goals.
• The best weight loss medication for you will depend on your health history and BMI. Your healthcare provider can advise you in an online consultation.

The Rise of At-Home Weight Loss Injections

From fad diets to calorie counting apps, there's no shortage of advice on how to lose weight. But now, with GLP-1 weight loss injections like Wegovy and Mounjaro, people living with obesity can leave the guesswork behind and look to clinically proven treatments to help them reach their health goals.

Though they’ve become popular for weight loss, GLP-1 medications were originally approved to treat type 2 diabetes in 2005. [1] It was soon discovered that they not only helped to regulate blood sugar, but also led to significant weight loss. Wegovy was approved for weight management in the UK in 2021, with Mounjaro following in 2023. Now, they're prescribed for obesity management to those who are eligible, with potentially life-changing results.

What Are Injectable Weight Loss Medications?

Injectable weight loss treatments belong to a class of medications called GLP‑1/GIP dual agonists (which stands for glucagon-like peptide-1/glucose-dependent insulinotropic polypeptide receptor agonists).

The most popular ones include tirzapatide (Mounjaro), semaglutide (Wegovy) and liraglutide (Saxenda). Taken at home using a ‘pen' that you self-inject under the skin, they're both convenient and effective for weight management.

Weight loss injections work in multiple ways: [2]

• They mimic naturally occurring hormones in your body to help stimulate insulin and reduce blood sugar levels.
• Some also help to quieten hunger and craving centres in your brain, helping to increase feelings of fullness and reduce your appetite.
• They slow down the rate at which food leaves your stomach, to keep you feeling fuller for longer.

GLP-1s can also improve obesity-related health risks by helping you to lose weight. For example, they can help to reduce the risk of cardiovascular diseases, as well as improving obstructive sleep apnoea, type 2 diabetes, high blood pressure, and high cholesterol. [3, 4, 5]

Comparing Leading At-Home Weight Loss Injections

The best injection for weight loss will depend on your current health, your medical history, and your goals. We’ve compared some of the more popular GLP-1 agonists so you can find the one that’s right for you.

Semaglutide (the active ingredient in Wegovy)

How it works: Wegovy is a GLP-1 (glugacon-like peptide-1) receptor agonist, which means it mimics the natural GLP-1 hormone in your gut. It’s designed to be injected once a week.

Results: In clinical trials, patients taking semaglutide 7.2mg experienced weight loss of 20.7% in 72 weeks. [6]

Tirzepatide (the active ingredient in Mounjaro)

How it works: Mounjaro is designed to be injected once a week. It’s different to Wegovy because it mimics two naturally occurring hormones instead of just one. That’s why it’s known as a dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glugacon-like peptide-1) receptor agonist.

Results: The strongest injection in terms of results, research shows that Mounjaro leads to more significant weight loss than semaglutide treatments like Wegovy. [7] In clinical trials, patients taking tirzepatide experienced weight loss of 22.5% after 72 weeks of treatment. [8]

Liraglutide (the active ingredient in Saxenda)

How it works: Saxenda is a GLP‑1 receptor agonist, like Wegovy. However, it’s designed to be injected daily, starting with a dose of 0.6 mg in the first week and gradually increasing as your body adjusts.

Results: Saxenda is 3x more effective for weight loss than diet and exercise alone. In trials, patients experienced weight loss of 8% over 56 weeks of treatment. This makes it less effective than the weekly injectable treatments, which are becoming more popular. [9, 10]

Are Weight Loss Injections Safe and Are You Eligible? 

Defining obesity

Wegovy, Mounjaro, and Saxenda can be prescribed to adults with a BMI of 30 or more (which is classed as obesity). However, adults with a BMI of 27 or more can also qualify if they have other health problems linked to their weight. These usually include things like type 2 diabetes, high cholesterol, or high blood pressure.

Side effects

Like many medications, GLP-1 injections can cause some side effects, including:

• Nausea
• Diarrhoea
• Constipation
• Indigestion
• Vomiting

Other common side effects include allergic reactions, dizziness, stomach pain, bloating, gas, fatigue, hair loss, and increased heart rate.

More severe side effects include pancreatitis, acute gallbladder disease, acute kidney injury, and anaphylactic reactions. [11]

Your eligibility

Weight loss injections have to be prescribed by a clinician. First, you’ll need to have a BMI and health assessment to check if they’re suitable for you and to rule out any reasons it shouldn’t be used. If you’re an eligible candidate, they can then set out your treatment plan and which medication will work best for you.

GLP-1s should not be used when trying to conceive, pregnant, or breastfeeding. Mounjaro can also affect the contraceptive pill, so you’ll need to use a non-oral method to stay protected.

More severe side effects mean you should not use weight loss injections if you have a personal or family history of medullary thyroid cancer (MTC), or if you have Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). [12]

Other red flags include certain kidney, liver and gut diseases, as well as past experiences of pancreatitis.

Maximising Results with Lifestyle Changes

It’s important to understand that these medications are not meant as a standalone fix to help you lose weight.

Weight loss injections are highly effective, but they’re just one piece of the puzzle when it comes to your health. These medications should always be used alongside healthy lifestyle habits (a reduced-calorie diet and increased physical activity) to lose weight and keep it off.

That means eating well, sleeping well and moving more. Sleep quality can affect your weight, and getting into good habits will help make sure you’re not too tired to keep up an exercise routine. It doesn’t have to be the gym or expensive classes, either. There are plenty of ways to exercise at home when taking GLP-1s to help preserve muscle mass as you lose fat.

Starting your weight loss journey 

We hope this guide has helped you to better understand the weight loss treatments that are available and whether GLP-1 injections could work for you. But finding the right medication always starts with a thorough consultation to hear about you, your goals, your state of health and family history.

Ready to get started? Find out what treatment is suitable for you with MedExpress.

References

1. Kolterman OG, Kim DD, Shen L, Ruggles JA, Nielsen LL, Fineman MS, Baron AD. Pharmacokinetics, pharmacodynamics, and safety of exenatide in patients with type 2 diabetes mellitus. Am J Health Syst Pharm. 2005 Jan 15;62(2):173-81. doi: 10.1093/ajhp/62.2.173.
2. Shankar A, Sharma A, Vinas A, Chilton RJ. GLP-1 receptor agonists and delayed gastric emptying: implications for invasive cardiac interventions and surgery. Cardiovascular Endocrinology & Metabolism [Internet]. 2024 Dec 4;14(1). Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC11620716/
3. ‌Lamija Ferhatbegović, Mršić D, Amra Macić-Džanković. The benefits of GLP1 receptors in cardiovascular diseases. Frontiers in clinical diabetes and healthcare [Internet]. 2023 Dec 8;4(1293926). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10739421/
4. ‌D’Annibale DA, Mimoto M, McCowen KC, Malhotra A. Glucagon-like peptide-1 receptor agonists for the treatment of obstructive sleep apnea. Current Opinion in Pulmonary Medicine [Internet]. 2025 Aug 22;31(6):591–6. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC12538296/
5. Lincoff AM, Brown-Frandsen K, Colhoun HM, Deanfield J, Emerson SS, Esbjerg S, Hardt-Lindberg S, Hovingh GK, Kahn SE, Kushner RF, Lingvay I, Oral TK, Michelsen MM, Plutzky J, Tornøe CW, Ryan DH; SELECT Trial Investigators. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. N Engl J Med. 2023 Dec 14;389(24):2221-2232. doi: 10.1056/NEJMoa2307563. Epub 2023 Nov 11. PMID: 37952131.
6. Wharton S, Freitas P, Hjelmesæth J, Kabisch M, Kandler K, Lingvay I, Quiroga M, Rosenstock J, Garvey WT; STEP UP trial group. Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial. Lancet Diabetes Endocrinol. 2025 Nov;13(11):949-963. doi: 10.1016/S2213-8587(25)00226-8. Epub 2025 Sep 14. PMID: 40961952.
7. 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
8. ‌Frías JP, Davies MJ, Rosenstock J, Pérez Manghi FC, Fernández Landó L, Bergman BK, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. New England Journal of Medicine [Internet]. 2021 Jun 25;385(6):503–15. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2107519
9. Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine [Internet]. 2022 Jun 4;387(3):205–16. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
10. Pi-Sunyer X, Astrup A, Fujioka K, Greenway F, Halpern A, Krempf M, Lau DC, le Roux CW, Violante Ortiz R, Jensen CB, Wilding JP; SCALE Obesity and Prediabetes NN8022-1839 Study Group. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. N Engl J Med. 2015 Jul 2;373(1):11-22. doi: 10.1056/NEJMoa1411892. PMID: 26132939.
11. ‌‌Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen - Summary of Product Characteristics (SmPC) - (emc)
12. Mounjaro: Uses, Dosage, Side Effects & Warnings [Internet]. Drugs.com. Available from: https://www.drugs.com/mounjaro.html