The Wegovy weight-loss pen is an injectable treatment available by prescription, with semaglutide as its active ingredient. It has been approved for weight loss by the UK's regulatory authority (MHRA) and recommended by NICE for weight management, and first became available in the UK in September 2023.
The Wegovy weight-loss pen is suitable for people with a BMI of 30 or above, or a BMI of 27 or above combined with a weight-related health condition such as prediabetes or high blood pressure.
The Wegovy weight-loss pen helps rebalance appetite, reduces cravings for sweets and snacks, and slows down how quickly the stomach empties, so you feel fuller for longer after meals. It's given as an injection once a week, with a dose-titration schedule that builds up to a maximum Wegovy dose of 2.4mg.
While using the Wegovy weight-loss pen, it's generally recommended to switch to a lower-calorie diet, build healthier eating habits, and exercise regularly for the best possible results.
How does the Wegovy weight-loss pen help you lose weight?
The Wegovy weight-loss pen works by mimicking a natural hormone called GLP-1 (glucagon-like peptide-1). This hormone helps regulate blood sugar levels and signals to receptors in the brain that are involved in managing appetite.
The Wegovy weight-loss pen supports weight loss because it:
- Reduces appetite, so you feel full without needing to eat as many calories
- Slows down how quickly food leaves the stomach, helping you feel full for longer
- Helps keep blood sugar levels more stable, reducing cravings and blood sugar spikes (especially helpful for people with prediabetes or insulin resistance)
Like other weight-loss injections, the Wegovy weight-loss pen works best when combined with a suitable nutrition plan and regular exercise.
When does the Wegovy weight-loss pen start working?
The Wegovy weight-loss pen begins working from your very first injection, and you may start feeling fuller for longer within just a few days.
In the first month of using the Wegovy weight-loss pen alongside a healthy diet and regular exercise, you can generally expect to lose around 2% of your starting body weight. Results become more noticeable as you follow the dose-titration schedule and move up to higher doses.
"Noticeable weight loss can take anywhere from a few weeks to several months, and is usually assessed after 6 months of continuous use of the Wegovy weight-loss pen, checking whether weight has dropped by at least 5% from the starting point. If it hasn't, it may be worth discussing together whether to continue." — Dr Brenda Ikeji, Medical Editor
How effective is the Wegovy weight-loss pen?
The Wegovy weight-loss pen is an effective option for weight loss — research shows that the maintenance dose of 2.4mg works for around 83.5% of people who use it.
After 68 weeks of continuous use at the 2.4mg Wegovy dose, average weight loss was around 17% of starting body weight, compared with an average of about 2.4% in the group using a placebo.
Additional results from using the Wegovy weight-loss pen
Beyond weight loss itself, studies have also found that using the Wegovy weight-loss pen reduced waist circumference by an average of 13.5 centimetres and lowered systolic blood pressure by an average of 6.2 mmHg. These figures come from people who used the medication alongside diet and exercise, so making lifestyle changes both during and after treatment is essential for getting the best results and maintaining them long-term.
How long do you need to use the Wegovy weight-loss pen?
How long you use it for depends on your personal goals — you can continue until you reach your desired weight, and keep using it afterward to help maintain your results for as long as you're happy to. The Wegovy weight-loss pen has been confirmed safe for long-term use.
Progress is usually assessed after 6 months of use. If weight has dropped by at least 5% from the starting point and there are no severe Wegovy side effects, you can keep using it for as long as it continues to benefit your body.
What happens when you stop using the Wegovy weight-loss pen?
When you stop using it, semaglutide's appetite-controlling effect wears off, so there's a chance weight may start to return. A 2025 study found that weight can begin increasing noticeably around 8 weeks after stopping, and within 1 year of stopping, users may regain up to 66% of the weight they had lost.
That's why building good eating habits and exercising regularly while on the medication is so important — it helps prepare your body to maintain the results on its own once you're no longer relying on the medication.
Who is a good candidate for the Wegovy weight-loss pen?
It's suitable for people aged 18 and over who want extra support managing their weight, as long as they don't have an underlying condition or take a medication that could affect how semaglutide works. The Wegovy weight-loss pen is not suitable for anyone who is pregnant, planning to become pregnant, or breastfeeding.
Basic eligibility criteria:
- A body mass index (BMI) of 30 or above
- A BMI of 27 or above, combined with a weight-related health condition such as high blood pressure, cardiovascular disease, or sleep apnoea
How to use the Wegovy weight-loss pen
The medication comes as a self-injection pen used once a week. It's easy to use, with no need to measure out doses yourself, since each pen contains enough medication for 4 doses (4 weeks' worth). It's best to inject on the same day and at the same time each week for maximum effectiveness and to help reduce the chance of side effects.
Where to inject the Wegovy weight-loss pen
You can choose to inject into the abdomen, thigh, or upper arm (if someone else is helping with the injection), whichever is most convenient for you. Rotate the injection site each week rather than using the same spot again, to help reduce skin irritation or discomfort.