Should you be using weight loss injections?

If you’ve been trying to lose weight lately, you may have heard of the new weight loss injections, semaglutide, or liraglutide. Or the brand names Saxenda, Ozempic, or Wegovy. These injections are a game changer in the world of weight management, and it offers another pharmaceutical option for weight loss. 

This blog post is going to cover everything you need to know about them.

Note that this blog post is not a substitute for medical advice, and you should discuss this with your GP if you want further information.

What is semaglutide/liraglutide and how does it work? 

Semaglutide and liraglutide are GLP-1 (glucagon like peptide 1) agonists. This means they’re a similar structure to GLP-1 and so can bind to its receptor on bodily cells and invoke a reaction. GLP-1 is a hormone that helps to regulate appetite and energy intake. It does this by increasing insulin release, reducing glucagon release, and slowing down how fast your stomach empties.

So, these weight loss injections mimic the GLP-1 hormone and help keep you fuller for longer with a lower appetite. This leads to weight loss as if you’re not feeling hungry as often, you’ll eat less and be in a calorie deficit.

These drugs were originally used for supporting people with type 2 diabetes (T2DM) as they can help control blood sugar levels by the increased insulin secretion. But the weight loss effects were also noticed, and recent evidence has shown that it can be used in weight management too.

How do you take semaglutide/liraglutide? 

These medications are given via injection under the skin. You’ll have to inject yourself and it can be on your stomach, thighs, or upper arm. The syringe is prefilled and depending on the type you have, you either adjust the dosage yourself by twisting a dial or it’ll come at a set dose.

Semaglutide is a weekly injection that usually starts at 0.25mg each week. You start on a small dose and increase it every 4 weeks until you get to a maintenance dose.

Liraglutide is a daily injection and starts at 0.6mg. You can then build up to 3mg a day.

Starting on a low dose and building it up is meant to help manage some of the gastrointestinal side effects that you may experience.

You can also take these medications orally as a tablet, but this isn’t typical use.

How much weight can you lose?

There’s lots of research testing the effectiveness of these GLP-1 agonists.

In 2021, a study found that people on semaglutide lost on average 14.9% of their body weight, when using it alongside diet and exercise. This is compared to people who used diet and exercise alone to lose weight. These people lost an average of 2.4% of their body weight. The semaglutide dose was 2.4mg and it was used for 68 weeks.

Another study found that, alongside diet and exercise, people taking 0.5mg of semaglutide weekly lost an average of 3.73kg over 68 weeks. At a higher dose of 1mg of semaglutide, 4.53kg was lost. People just using diet and exercise, lost 0.98kg.

Evidence with liraglutide shows good results too. People that used liraglutide for a year lost an average of 6.8kg. Those who used liraglutide alongside a vigorous exercise regime, lost an average of 9.5kg. This was at a dosage of 3mg of liraglutide a day.

As you can see, there's lots of weight loss using these treatments.

What's the small print?

These GLP-1 agonists are a really useful tool in weight management but it’s not a miracle drug. Lifestyle changes still need to be made alongside the injections. In fact, they’re only allowed to be sold as long as there’s a disclaimer that says it’s for use alongside a reduced calorie diet and increased physical activity.

Making permanent changes to your diet and exercise regime is the only way to have long lasting weight loss, and these injections can be the cherry on top. But it can’t be used alone as the only method to weight loss and it’s not a quick fix.

These drugs are very effective at inducing weight loss. However there is research that suggests that once you stop them, you could regain up to two-thirds of the weight lost. 

Weight loss, if put simply, usually boils down to diet and exercise so it's important to have this nailed down. And I’ve got lots of blog posts to help with this:

How to lose weight without starving yourself

Three tips to help reach your health goals

The best diet for weight loss

Who can get semaglutide?

The current clinical guidance has criteria for who’s eligible for semaglutide on the NHS.

It can only be used if: 

• It’s for a maximum of 2 years and it’s within a specialist weight management service
• You have at least 1 weight related comorbidity (e.g., type 2 diabetes, raised cholesterol, high blood pressure)
• You have a BMI of at least 35kg/m2, or a BMI of 30-34.9kg/m2 and meet the criteria for specialist weight management services. A lower BMI threshold ~ 32.5kg/m2 is used for people of an Asian, Middle Eastern, African, or Caribbean descent.

It would be discontinued if less than 5% of body weight is lost within 6 months as it’s unlikely to be making a significant difference to someone’s weight.

Who can get liraglutide? 

There are slightly different criteria for obtaining liraglutide on the NHS. You have to meet all of these:

• You have a BMI of at least 35kg/m2 (or 32.5kg/m2 if you’re in an ethnic minority group with a higher risk)
• You have non-diabetic hyperglycaemia (high blood sugar levels without having diabetes)
• You have a higher risk of cardiovascular disease based on factors like high blood pressure and high cholesterol levels
• It has to be given within a tier 3 weight management service

A lot of commercial weight loss programmes are also offering these injections alongside a structured weight management programme. These programmes are typically at your own cost.

What’s the risks/side effects?

As with any medication, there are side effects. Common side effects with semaglutide are: nausea, vomiting, constipation, diarrhoea, dizziness, fatigue, burping, and gastrointestinal discomfort. The rarer side effects are an altered taste, and acute pancreatitis.

Side effects with liraglutide are similar with nausea, vomiting, constipation, diarrhoea, dizziness, fatigue, burping, and gastrointestinal discomfort also common. But there’s more: dry mouth, headaches, gallbladder disorders, increased risk of infection, toothache, and skin reactions could also occur with liraglutide.

Rarer side effects with liraglutide are pancreatitis, dehydration, kidney dysfunction, and feeling generally unwell.

Overall, semaglutide and liraglutide are a really useful additions to helping people manage their weight. But, making lifestyle changes is still essential, and these drugs are not without side effects.

Key points:

• Semaglutide and liraglutide are GLP-1 agonists. They mimic a hormone in the body and make us feel fuller for longer, have a reduced appetite, and so lose weight.
• These medications are given via injecting yourself in the stomach, thigh, or upper arm.
• Using semaglutide or liraglutide at their highest doses, and alongside diet and exercise, can lead to significant weight loss.
• To get these medications on the NHS you need to have a BMI of 35kg/m2 or more and another condition such as type 2 diabetes, or high blood pressure.
• These injections aren’t a magic pill, changing your diet and increasing your exercise is still required.
• The side effects of these medications can include nausea, constipation, diarrhoea, dizziness, and fatigue.

I hope this blog post has given you an insight into these medications and you know a bit more about them.

Bye for now! 👋

References:

https://www.nice.org.uk/guidance/ta875

https://www.nice.org.uk/guidance/ta664/chapter/1-Recommendations

https://www.medicines.org.uk/emc/product/13801/smpc#gref

https://bnf.nice.org.uk/drugs/semaglutide/

https://bnf.nice.org.uk/drugs/liraglutide/

https://www.medicines.org.uk/emc/product/2313

https://www.nejm.org/doi/full/10.1056/NEJMoa2032183

https://www.nejm.org/doi/10.1056/NEJMoa2028198?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8717485/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8717485/

https://dom-pubs.onlinelibrary.wiley.com/doi/10.1111/dom.14725