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20+ years in obesity care

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Our at-home weight loss programmes explained

SemaPen's programmes are tailored to you. Sign up to access bespoke treatment options, including injectable weight loss medications that work for around 95% of patients.

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.

Start your consultation

To be prescribed weight loss medication in the UK, you must first have a medical consultation. Our online consultation is designed by obesity experts and gives you an answer instantly

Enjoy tailored support

When you subscribe to SemaPen, you get proactive, tailored support from some of the UK's most trusted obesity experts. They'll review your consultation and recommend the best treatment for you.

Receive your pen

If you're approved for a medication programme, you'll receive your first 4-dose weight loss injection pen within a few days. We send your next pen automatically, so you'll never miss a dose.

Explore our programmes

SemaPen offers two game-changing injectable drugs for weight loss: Mounjaro and   Wegovy.


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

Mounjaro programme

Mounjaro is among the latest clinically proven prescription drugs for weight loss available in the UK. Take it weekly for 72 weeks and you can expect to lose around 21% of your body weight.***

Discover Mounjaro
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21% average weight loss***

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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 programme

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.****

Discover Wegovy
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15% average weight loss****

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Works for around 95% of patients

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Discreet packaging and fast delivery

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The slimming pen that started it all

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 online consultation, it goes directly to our experts. They'll carefully review your answers and recommend the best treatment option based on your unique needs and medical history.


This might be an injectable drug for weight loss. Or it could be a bespoke at-home weight loss programme guided by our qualified dieticians and psychologists.

For those who could most benefit, we might instead recommend bariatric surgery.



Only SemaPen gives you access to such a wide range of treatments and such specialised support. 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
  • Dietary advice and support
  • Access to expert psychologists
  • Bariatric surgery


Which programme is right for me?

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

Wegovy Mounjaro
Active ingredient Semaglutide Tirzepatide
How it works Mimics 1 hormone: GLP-1 Mimics 2 hormones: GLP-1 and GIP
Dosage Once-weekly injection Once-weekly injection
How long to reach the maximum dose? 5 months 6 months
Average weight loss (non-diabetic) 15% of starting weight**** 21% of starting weight***
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.
Availability in the UK Available Available
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