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20+ years in obesity care

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All-in-one, feature-rich digital health app

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Cancel at any time*

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Money-back guarantee** 

Find the weight loss programme that works for you

SemaPen is a UK company founded by some of the country's most trusted obesity experts.


For you, this means extra peace of mind. Not only can you benefit from the UK's most effective slimming drugs, but you'll also get tailored support from real specialists with years of experience.



If you're eligible for our programmes, you'll receive everything you need to start your weight loss journey at home. That includes weight loss pens, a smart scale and access to instant online support via the SemaPen app.

The Mounjaro and Wegovy app built by experts

SemaPen is a UK company founded by experts and built on decades of real-life obesity treatment experience. As part of Phoenix Health, we've helped people like you lose weight for more than 20 years.


For you, this means extra peace of mind. With our expertise on your side, you'll be all set to make the most of our effective weight loss programmes. These can help you lose around 15% to 21% of your body weight.¹

What you get with the SemaPen digital health app

If you're eligible for our programmes, you'll have everything you need to start your weight loss journey at home in the palm of your hand. That includes:


  • A science-backed weight loss programme specially selected for you.
  • A support plan tailored to your needs. Options range from intelligent health tracking to face-to-face video consultations with psychologists.
  • Other useful app features, like weight loss forums and the SemaPen Academy. (Link to app features page)


You'll also receive a Withings® Body scale worth £60. Plus, if you choose one of our medication programmes, you'll get your next dose delivered automatically to your door.

How it works

Start your consultation

To be prescribed weight loss medication in the UK, you must first attend an online consultation. Ours is designed by obesity experts. It's simple to complete in the app and instantly lets you know which of our programmes could be right for you.

Enjoy tailored support

Once you're all set with a programme, you can choose the level of support that suits you. Every subscriber enjoys access to premium nutrition app features, such as health tracking, expert support and educational content from our SemaPen Academy. Plus, with our Gold and Silver plans, you get extra perks like a 10-month guided online fitness plan.

Get started with your programme

If you're approved for a programme, you'll receive your first weight loss injection pen or meal replacement shakes within a few days. We send your next batch automatically, so you'll never miss out.

Feel more supported than ever with our revolutionary digital health app

Safe and fast onboarding

Complete a secure digital consultation and get started almost straight away. Simply answer a few health questions, receive your programme recommendations instantly and choose the support plan that's right for you.

Smart health dashboard

Your Withings® Body scale sends every weigh-in straight to the app, so you and your team can see your progress in real time. Log side effects, track mental health and follow your medication schedule – all in one place.

Tailored professional support

Choose the level of support that feels right for you, from light-touch check-ins to regular face-to-face contact with clinicians over video chat.

Motivation and learning built in

Stay inspired with in-app badges, community forums and SemaPen Academy lessons on nutrition and healthy habits. It could be the extra boost you need to keep the weight off long-term.

Explore features

Explore our programmes

At SemaPen, we provide expert-led solutions for anyone wanting to lose weight. That's why we offer a medication-free meal replacement programme, alongside powerful injectable weight loss medications as part of our GLP-1 app programmes.


Complete your digital consultation today and let our obesity specialists recommend the best treatment path for you.

Mounjaro app programme

21% average weight loss¹

Mounjaro is among the latest clinically proven prescription medications for weight loss available in the UK. Patients who take it weekly for 72 weeks lose around 21% of their body weight on average.¹


Here's what you can get with our Mounjaro app programme:

Discover Mounjaro
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21% average weight loss¹

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Works for around 95% of patients

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Discreet packaging and fast delivery

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The latest injectable weight loss medication

Wegovy app programme

15% average weight loss²

Approved in 2023, Wegovy has proven to be an effective weight loss medication in clinical trials and real-world rollouts. Wegovy patients typically lose around 15% of their body weight.²


Here's what you get with our Wegovy app programme:

Discover Wegovy
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15% average body weight loss²

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Works for around 95% of patients

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Discreet packaging and fast delivery

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The weight loss pen that started it all

SemaHealth programme

Drug-free option

Don't want weight loss drugs? The SemaHealth programme could be right for you. It includes all the tailored support and handy features you expect, but swaps injectable medications for tasty, satisfying, nutrient-rich soups and shakes.


Here's what you can expect with SemaHealth:

Discover programme
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10–15% average weight loss³ ***

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Tasty, nutritious meal replacement shakes that leave you feeling full

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Direct access to obesity experts for tailored advice

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Health tracking features and exclusive content in the SemaPen app

Bespoke treatment options

SemaPen is unique. We're part of Phoenix Health – one of the UK's leading obesity clinics. For you, this means expert, tailored support from some of the most trusted specialists in the country.


When you take our in-app digital consultation, you'll find out instantly whether you're eligible for one of our weight loss programmes. Then, you'll be recommended the best treatment option based on your unique needs and medical history.


This may be an injectable medication for weight loss or a drug-free nutrition programme. And, for those who could benefit the most, we may recommend bariatric surgery.

Only SemaPen gives you access to such a wide range of treatments, plus daily support from a digital health app loaded with useful features. It's because we know that no two weight loss journeys are the same – and we want to give you the best chance of success.


  • Injectable weight loss medications
  • Drug-free SemaHealth programme
  • Personalised support plans
  • Tailored support through the SemaPen app
  • Bariatric surgery for those who could benefit most

Which programme is right for me?

Compare SemaPen's at-home weight loss programmes and find the one that works best for you.

Wegovy Mounjaro SemaHealth programme
Active ingredient Semaglutide Tirzepatide No medication
How it works Mimics 1 hormone: GLP-1 Mimics 2 hormones: GLP-1 and GIP Replace daily meals with tasty, nutritionally complete shakes and soups
Dosage Once-weekly injection Once-weekly injection No medication
How long to reach the maximum dose? 5 months 6 months No medication
Average weight loss (non-diabetic) 15% of starting weight² 21% of starting weight¹ 10% to 15% of starting weight³ **
Side effects Nausea, constipation, diarrhoea, vomiting, acid reflux, belching and bloating are most common. Similar to Wegovy but with less nausea. Hair thinning (temporary) – daily multivitamins advised. Interferes with the action of the oral contraceptive pill. Can have temporary side effects, including constipation, headaches, fatigue, irritability and sensitivity to cold.
Availability in the UK Available Available Available
Prices start at**** £189 per month £225 per month £1,072.91 for a full 12-month treatment programme