When so many of my clients are considering (or are already taking) weight loss medication I thought that it would be sensible to ask an expert to shed more light on these easily obtainable drugs to help you to make informed choices.
Elaine Allerton is an Advanced Diabetes Specialist Dietitian in the NHS.
She also offers private consultations to support nutrition and lifestyle change. She is unable to prescribe weight loss medications but is very happy to help you manage the side effects, and reduce the risk of muscle mass loss.
Elaine writes:
“Obesity has become one of the biggest public health challenges of our time. It’s linked to type 2 diabetes, heart disease, joint pain, and even certain cancers — not to mention the emotional impact it can have on self-esteem and daily life. In the UK, around 28% of men and 29% of women are now classed as obese, according to the latest National Diet and Nutrition Survey.
So it’s no surprise that weight loss injections — medications first developed to treat type 2 diabetes — have become a hot topic.
What Exactly Is GLP-1?
GLP-1 (short for glucagon-like peptide 1) is a naturally occurring hormone that helps regulate appetite and blood sugar. It signals to your brain that you’re full and slows digestion so you feel satisfied after a meal.
For some people living with obesity, this system doesn’t work as efficiently as it should. That’s where GLP-1 medications like Ozempic, Wegovy, Saxenda, and Mounjaro come in — they mimic the natural effects of GLP-1.
They can:
- Slow down digestion so you feel fuller for longer
- Reduce food cravings and “food noise” in the brain
- Boost insulin release to support healthy blood sugar levels
Mounjaro goes one step further by also mimicking another hormone, GIP, which enhances these effects even more.
Who Are They For?
These medications are for people living with obesity, not for those hoping to lose a few pounds before a holiday or event.
The NHS can prescribe them for weight loss, but the criteria are strict. Private prescriptions are available from registered pharmacies (such as Asda, Boots, Lloyds, and Superdrug), but you’ll still need to meet specific criteria and share evidence of your BMI, alongside consent for the pharmacy to inform your GP.
⚠️ Tip: Always check that the pharmacy is registered with the General Pharmaceutical Council — and never buy from unverified online sources.
Some of the best private services also offer coaching and support to help you build lasting habits, not just rely on the medication.
Do They Work?
In a word — yes.
GLP-1 medications are the most effective weight loss drugs available, with results that can approach those of bariatric surgery.
But — and this is important — they’re only one piece of the puzzle.
Up to 40% of weight loss with GLP-1 drugs may come from lean body mass (muscle). Without resistance training or enough protein, you risk losing muscle, slowing your metabolism, and increasing your chances of regaining weight.
💡 You don’t need to increase your dose every month. If you’re losing weight steadily and managing side effects, you can stay on a lower dose.
Common Side Effects
Most people tolerate these medications well, but side effects can include:
- Nausea
- Constipation
- “Egg burps” (a sulphurous aftertaste)
- Muscle loss
- Hair loss
- “Ozempic face” or “Ozempic butt” — volume loss in the face and glutes
- Gallstones
- Pancreatitis (rare but serious — seek urgent help for severe abdominal pain)
There’s also emerging research on whether GLP-1 drugs affect bone density, which may be especially relevant for women in midlife and beyond.
⚠️ If you’re using Mounjaro and take oral contraceptives or oral HRT, speak to your doctor — you may need to switch to a non-oral form (like a barrier contraceptive method or Mirena coil for the progesterone element of your HRT).
Lifestyle Still Matters
Weight loss injections can be a powerful kick-start, but they’re not a replacement for healthy living.
Nutrition, movement, and mindset remain the foundation for sustainable success.
While GLP-1 drugs help control physical hunger, they don’t address emotional eating, habits, or environmental triggers — and that’s where real, long-term change happens.
Final Thoughts
GLP-1 injections can be life-changing for those living with obesity, but they’re not magic. The best results come when medication is paired with personalised nutrition, resistance training, and behaviour change support.
📞 Connect with Elaine:
- LinkedIn: Elaine Allerton RD
- Facebook: Elaine Allerton Dietitian
- Instagram: @rd_elainea
