Wegovy injection: How it works for weight loss

When attempting to shed excess body weight, you might discover that the journey is trickier than anticipated. Sometimes, even with a reduced-calorie diet and increased physical activity, achieving weight loss can be challenging.

That's why weight loss medication has gained popularity as a treatment option. You've probably come across several names of weight loss medications, and stands out as one of the most effective weight loss drugs available.

We've compiled a guide covering everything you need to know about the Wegovy pen, from how it works to help weight loss and its effectiveness. Plus, we'll explore the potential for long-term use of Wegovy.

What is Wegovy?

Wegovy is an effective weight loss drug with an active ingredient of semaglutide. Wegovy is used as a chronic weight management tool for those with excess weight and weight-related health problems such as high blood pressure or high cholesterol [1].

Wegovy is a weight management tool and is most effective when combined with physical activity and a reduced-calorie diet.

In order to get a prescription for Wegovy, there are some requirements you have to meet:

• A body mass index (BMI) of 30 or more, indicating obesity
• A BMI of 27 or higher, categorising as overweight, coupled with at least one weight-related health condition such as high blood pressure, type 2 diabetes, or elevated cholesterol levels [2]

It's also important to know that Wegovy should not be used in patients with a personal or family history of medullary thyroid carcinoma or in patients with a rare condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) [3].

It's best to talk to a trusted healthcare professional about whether or not Wegovy could be a good fit for you. They'll also be able to discuss any interactions it may have if you are taking any other prescription drugs.

How does Wegovy work for weight loss?

Wegovy contains the active ingredient semaglutide. This is a glucagon-like peptide-1 (GLP-1) receptor agonist, which targets the area of the brain that helps to regulate appetite, especially after eating, and slows down stomach emptying, making you feel fuller for longer [4].

Once you have a prescription, you'll be able to get your Wegovy pen. This is a pre-filled injection pen containing a liquid solution. This pen is normally administered once a week via a subcutaneous (that means under the skin) injection.

You'll be taught by your doctor or another healthcare provider about how to self-administer Wegovy injections in the comfort of your home.

How effective is Wegovy?

Wegovy works well for weight loss in people with a higher body mass index, those wanting to lose extra weight and those navigating health issues like high blood pressure.

Studies show Wegovy can lead to big weight loss results. In clinical trials, patients on the highest possible dose of Wegovy lost up to 20.7% of their body weight [5], showing that it can be highly effective when used consistently and with the right support. This dose is expected to be available in the UK soon.

With Juniper, Wegovy is delivered as part of a complete programme that includes expert care, coaching, and tracking tools — to help you get the most from your treatment.

Remember, the way Wegovy works can differ for each person, leading to varied results. There are also concerns about how well it works over a long time and if you need to keep using it to keep the weight off. For best results, it's advised to use Wegovy alongside a regular exercise routine and low-calorie diet.

Curious about real patient outcomes? Explore Wegovy weight loss transformations.

How should I use Wegovy?

While it's always best to talk to a healthcare professional about the best way to implement any new drug, there are some general guidelines for what to expect when using Wegovy and how to use it effectively:

• Wegovy is available in multiple strengths, including 0.25 mg, 0.5 mg, 1.0 mg, 1.7 mg, and 2.4 mg
• Your doctor will likely start you on the lowest dosage of Wegovy, which is 0.25 mg once weekly
• After the first month, the dosage is increased to 0.5 mg once weekly, and then gradually increased every four weeks until the full dose of 2.4 mg is reached [6]
• It is important to switch the injection site each time and to follow the dose escalation schedule to minimise gastrointestinal adverse reactions [7]
• Wegovy should be used with a reduced-calorie meal plan and increased physical activity
• It is important to continue using Wegovy as directed by your healthcare provider to maintain weight loss

How long does Wegovy stay in your system?

Wegovy's half-life is about 7 days. This means that if you take the highest dose of 2.4 mg, after 7 days, about half (1.2 mg) will still be in your body [8]. Having an elimination half-life of roughly 1 week, Wegovy will remain in the bloodstream for approximately 5-7 weeks following the final 2.4 mg dose [9].

Remember, the time Wegovy stays in your body can be different for each person, leading to varying outcomes. Also, it's important to follow your healthcare provider's instructions to use Wegovy continuously for maintaining weight loss.

How long does Wegovy take to work?

How long it takes for Wegovy to work will differ from person to person, but there is some research to suggest that weight loss may begin within as little as 4 weeks.

When used alongside healthy eating and exercise here is a general timeline that you might expect to see when using Wegovy:

• People typically lose about 6% of their initial body weight at 12 weeks,
• People typically lose about 10% of their initial body weight at 20 weeks, and
• People typically lose around 15% of their initial body weight within a year.

However, it could take a few months before the complete benefits of Wegovy treatment become apparent, and the results will differ for each individual. If you're not losing weight on Wegovy, be sure to talk to your prescriber.

What is the recommended dosage of Wegovy?

The recommended dosage of Wegovy will differ from person to person and will depend on a few factors.

Generally speaking, your doctor will prescribe you the starting dose of 0.25 mg once weekly. After the first month, the dosage is typically increased to 0.5 mg once weekly. The dosage then gradually increases every four weeks until the full dose of 2.4 mg is reached [10].

The maintenance dosage of Wegovy in adults is typically 2.4 mg, but may be 1.7 mg once weekly depending on different factors such as starting weight and other weight-related conditions.

Can I drink alcohol while taking Wegovy?

Unfortunately, there haven't been a lot of studies conducted on the effects of drinking alcohol while taking Wegovy. Your healthcare professional will likely advise you to reduce your alcohol consumption or to avoid drinking alcohol completely while taking Wegovy for weight loss.

Here are some reasons why alcohol should be avoided:

Reduced effectiveness

Alcohol consumption on Wegovy may reduce its effectiveness in promoting weight loss.

Increased risks

Drinking alcohol while on Wegovy can increase the risk of side effects such as nausea, vomiting, and diarrhoea.

Added calories

Ever heard the term 'drinking your calories' or 'empty calories'? This is when increased calories are consumed by adding a drink other than water to your meal, and many people don't realise how many extra calories this contributes.

Alcohol is a big culprit in increasing your caloric intake. You might be advised to reduce or stop drinking alcohol during any weight loss journey as it can make it harder to maintain a healthy, calorie-reduced eating pattern.

Lowered blood sugar

Alcohol on its own can lower blood sugar levels, and when combined with Wegovy, it may further worsen the risk of low blood sugar (hypoglycaemia).

It is important to discuss your alcohol use with your healthcare provider while taking Wegovy, as they may recommend avoiding alcohol completely.

Can I switch from Mounjaro to Wegovy?

From 1 September 2025, Eli Lilly, the manufacturer of Mounjaro (tirzepatide), increased its UK list price to align with other developed countries. This nationwide change applies to providers including pharmacies, private clinics, and digital platforms.

In response, we’ve lowered the price of our Wegovy programme by 25%, and we’re making it easier for patients to switch without starting over, so that effective treatment remains within reach for as many people as possible.

So, if you've been wondering if you can switch from Mounjaro to Wegovy, the good news is that it's both safe and straightforward.

When making the switch, Juniper patients don’t need to restart at the lowest dose. If clinically appropriate, they can continue at a higher dose aligned with recent treatment history. We also only require a 7-day gap between your last Mounjaro dose and your first Wegovy dose — unlike most providers, who require 28 days.

At Juniper, we make that switch seamless and fully supported — so you can protect your progress without paying more than you need to. Our clinical switching protocol is is simple and safe:

• ‍Review — Your clinician assesses your treatment history and dose tolerance.‍
• Match — If eligible, you start on an equivalent high dose to avoid losing progress.‍
• Transition — Only a 7-day window is required between your last Mounjaro dose and your first Wegovy dose (most providers require 28 days).‍
• Support — Pharmacist check-ins, dose adjustments, and lifestyle guidance keep you on track.

Start your Wegovy switch today →

Can I take Wegovy long-term?

Wegovy has been developed as a long-term drug, so it is safe to be taken long-term for weight management. It is important to discuss the long-term use of Wegovy with a healthcare professional to determine if it is the right option for you and to discuss potential risks and benefits.

It's also important to find support for making additional lifestyle changes, such as consuming a reduced-calorie diet and increased physical activity.

Weight loss is a journey, so finding a holistic approach that suits your lifestyle and offers you additional support is the key to success. By taking the Juniper quiz, you can check your eligibility and kickstart, or restart, your journey towards a healthier and happier you. Juniper offers tailored treatment plans based on your needs, taking your experience with medication and goals into account.

If you're unsure where to start, simply begin by answering a few questions in our quiz and our clinicians will support you through this process.

How to store Wegovy

You should store your Wegovy pen in the fridge (2°C-8°C), though if necessary, prior to cap removal, you can keep it between 8°C-30°C for up to 28 days. You should discard the pen 6 weeks after first use, but be sure to store it properly.