Which GLP-1 Is Right for You?

So you’ve decided the best way to lose weight is with the help of a GLP-1. Congratulations on taking your health into your own hands. Deciding which GLP-1 is right for you can seem daunting. But with the help of your doctor, independent pharmacist and informative articles like this one, you can feel more confident about the best way to lose weight for you.

Calculate Your BMI

The first thing to do is to know whether a GLP-1 is actually suitable for you. GLP-1s are only suitable if you are obese, so you need to know what your BMI is. You can find that out using the BMI calculator here.

The calculator asks for information on your ethnic background because people from an Asian, Black African, African-Caribbean or Middle Eastern ethnic background have a higher chance of developing health problems at a lower BMI.

Your BMI result will be displayed as a number within a category:

• Underweight
• A healthy weight
• Overweight
• Obese

Overweight is defined as a body mass index of 25 to 30. Obesity is defined as a BMI of 30 or above.

Once you know your BMI, you can speak to your doctor or an independent pharmacist to confirm you’d like to start on a GLP-1.

How GLP-1s Work

All GLP-1s work by imitating the action of natural hormones in your body. The natural hormone GLP-1 acts naturally to trigger insulin release, which is another hormone that lowers the amount of glucose (sugar) in your blood.

GLP blocks glucagon secretion, which is a hormone that raises blood sugar. GLP also slows digestion, so it slows the amount of sugar going into your bloodstream from the food you eat and GLP also acts on areas of the brain that help you feel full.

So GLP-1 agonists, treatments that work like the natural product, work in different ways to cut down on the way sugar is being used in your body and converted into fat and also your perception of how full you feel. All of which helps you to lose weight.

As well as lowering blood sugar levels and reducing weight, studies show that GLP-1 agonists may have other potential benefits, like:

• Lowering blood pressure
• Improving lipid disorders
• Improving fatty liver disease
• Reducing your risk of heart disease and kidney disease
• Delaying the progression of diabetes-related nephropathy

Popular GLP-1 Treatments

Popular GLP-1 treatments are Wegovy® and Mounjaro®. The right one for you is dependent on what formulation might suit you and the best combination of benefits without too many side effects. People respond in an individual way to medicines, so try not to base your decision on how other people respond. You may not get side effects from a medicine that someone else does.

Most GLP-1s are available as injections. Recently popular treatment Wegovy® has become available as a pill too.

Let’s take a look at the options in turn.

Wegovy®

Wegovy® contains the active substance semaglutide. Wegovy® is available as a weekly injection using a specially designed pen, in five doses. Your dose will depend on where you are in your treatment journey. The starting dose is 0.25mg, with incremental dose increases until you reach 2.4mg.

Wegovy results from a study published in the New England Journal of Medicine in 2025 found that people on Wegovy lost 13.7% of their body weight over 72 weeks, plus lost an average 13.0cm in their waist circumference.1 A new higher dose of 7.2mg Wegovy® has recently been discovered to achieve even greater weight loss results than the standard dose. In a trial carried out jointly by University of Toronto and scientists at Novo Nordisk, nearly half of those receiving the Wegovy® higher dose lost 20% or more of their body weight.2

Wegovy® is available as a daily tablet too, if you feel more comfortable taking your medicine that way. When you wake up, just take your daily Wegovy® pill with a sip of water (up to 120 mL). It’s important that you take it on an empty stomach after a fasting period of at least 8 hours. Swallow it whole – don’t split, crush, dissolve or chew the Wegovy® pill as this might affect how well you absorb it.3

You can start eating, drinking, and taking other oral medication 30 minutes after taking the Wegovy® pill. Waiting at least 30 minutes makes sure that you absorb your Wegovy® pill properly.1

The Wegovy® once-daily tablet contains the same active ingredient as the Wegovy® pen injection; the GLP-1 analogue semaglutide, so it works the same way as the injection form of Wegovy®.

You can discuss with your doctor or pharmacist which formulation is right for you. It’s possible to swap from using the injection pen to taking the tablets if you change your mind about what’s right for you. You can start taking the tablets one week after your last Wegovy® injection.

Common possible side effects that you can experience from using Wegovy®, i.e. ones that affect more than 1 in 10 people include:

• Headache
• Feeling Sick (Nausea)
• Being Sick (Vomiting)
• Diarrhoea
• Constipation
• Stomach Pain
• Feeling Weak or Tired.1

These usually go away over time.

Let your doctor or pharmacist know if you are experiencing side effects. Usually the benefits of the treatment outweigh the inconvenience of common side effects. But it’s up to you to decide what is right for you.

Mounjaro®

Mounjaro® contains an active substance called tirzepatide (tir-zep-a-tide). Mounjaro® is a weekly injection available in five doses. Your dose will depend on where you are in your treatment journey. The starting dose is 2.5mg. This increases in increments of 2.5mg until you reach 15mg.

Like Wegovy®, Mounjaro® simulates the GLP-1 hormone, but it actually works on two hormones, not just one, in what’s known as a dual-hormone mechanism. Mounjaro® also activates the GIP (glucose-dependent insulinotropic polypeptide) hormone, reducing blood sugar levels by encouraging the pancreas to release insulin.4

Because of this dual mechanism, Mounjaro® typically produces more weight loss at standard doses than Wegovy®. Mounjaro® results from a study published in the New England Journal of Medicine in 2025 found that people on Mounjaro® lost 20.2% of their body weight over 72 weeks, while those on Wegovy® lost 13.7%. Those on Mounjaro® also lost an average −18.4 cm in their waist circumference vs an average −13.0 cm for those on Wegovy®.1

Common possible side effects that you can experience from using Mounjaro®, i.e. ones that affect more than 1 in 10 people include:

• Low blood sugar (hypoglycaemia) when tirzepatide is used for the treatment of type 2 diabetes with medicines that contain a sulphonylurea and/or insulin. If you are using a sulphonylurea or insulin, the dose may need to be lowered while you use tirzepatide. Symptoms of low blood sugar may include headache, drowsiness, weakness, dizziness, feeling hungry, confusion, irritability, fast heartbeat and sweating. Your doctor should tell you how to treat low blood sugar.
• Feeling sick (nausea)*
• Diarrhoea*
• Being sick (vomiting) – this usually goes away over time*
• Stomach (abdominal) pain
• Constipation
• Feeling tired (fatigue)
• Feeling less hungry (decreased appetite)4

*These side effects are usually not severe. They are most common when first starting Mounjaro® but decrease over time in most patients.

Ready to choose the GLP-1 that’s right for you? You can find expert independent advice by speaking to a pharmacist at SlimEase. Call us on 01932 393965 (during standard opening hours) or click here to email the team.