As we settle into 2025, research shows that the demand for and interest in weight-loss injections has exploded. According to online doctor, ZAVA, internet searches for Mounjaro (one of the most talked-about treatments) have increased by 3,881% since January 2024 – from 11,000 to 428,000.

A recent survey also revealed 24% of people would use weight-loss jabs if provided for free by the NHS – and a further 7% would be happy to buy them privately. One jab, Wegovy, is already available to some people on the NHS, and Mounjaro, will be available soon.

Alongside the near 30% of Brits prioritising health-related New Year’s resolutions, social media platform TikTok is thought to be a driving force behind this surge of interest – with thousands of videos dedicated to weight-loss treatments.

But what does the current research say?

How do weight-loss injections work?

In the UK, there are currently two weight-loss drugs available – semaglutide (marketed under the name Wegovy) and tirzepatide (sold as Mounjaro). Semaglutide is also used in Ozempic – a treatment for type 2 diabetes.

Both Wegovy and Mounjaro are taken as weekly injections, self-administered into the thigh, stomach, or upper arm. They work by mimicking a hormone called glucagon-like peptide-1 (GLP-1), which suppresses appetite. This is why experts refer to them as GLP-1 treatments.

Mounjaro also affects glucose-dependent insulinotropic polypeptide (GIP) – another hormone involved in metabolism and energy regulation.

But what does the research say?

Here’s what experts at ZOPA have to say about some common GLP-1 treatment myths…

1. GLP-1 treatments are ‘magic’ – False

While GLP-1 treatments can help to reduce appetite and increase fullness, they’re not a magic solution. For lasting results, treatment must be paired with regular exercise and a healthy, balanced diet.

2. GLP-1 treatments can help to regulate blood pressure – True

Research shows that GLP-1 treatments can help to control blood pressure – particularly in people with hypertension (high blood pressure). However, further studies are needed to confirm their efficacy for diabetes-related hypertension.

3. GLP-1 treatments can help anyone lose weight – False

GLP-1 treatments are only suitable for people with obesity, a BMI of 27, or other weight-related health conditions.

4. GLP-1 treatments are safe – Undetermined

Research has found that GLP-1 treatments can cause temporary side effects, such as nausea and bloating. While clinical studies suggest they’re safe for long-term use, it’s important to speak to a healthcare professional first to discuss suitability.

5. GLP-1 treatments may help to reduce inflammation – True

There’s growing evidence that GLP-1 treatments may help to reduce inflammation in several areas of the body, including the liver and brain – potentially offering benefits for conditions like Parkinson’s and Alzheimer’s disease.

6. GLP-1 treatments are addictive – False

There’s currently no evidence that GLP-1 treatments are addictive. Some animal studies even suggest they may reduce addictive behaviours.

7. GLP-1 treatments may affect mental health – Unknown

Initial studies suggest that GLP-1 treatments may benefit mental health. However, further research is needed.

Crystal Wyllie, a doctor at ZAVA, says: “Under proper medical supervision, weight loss injections can be a safe and effective tool for achieving lasting results. This growing awareness is an encouraging step toward reducing stigma and empowering more people to seek the right support for their health.”