Wegovy is one of the new generation of weight-loss drugs proving so popular that Britain faces a shortage, just a few months after they came on to the market.
It’s easy to see why those struggling with their weight are desperate to get hold of Wegovy (which also comes as a lower- dose version, known Ozempic): in trials, some volunteers lost a fifth of their body weight in a year. The drug is taken in the form of a once-a-week self-administered jab.
But what precisely does it do to the body? Here leading expert Wasim Hanif, a professor of diabetology and endocrinology at University Hospital Birmingham, reveals some of the positive – and negative – effects it can have…
HUNGER PANGS DISAPPEAR
First and foremost, you stop feeling hungry – this is one of the first things Wegovy patients notice: their desire to eat even their favourite foods vanishes within weeks.
The drug mimics the effects of a hormone called glucagon-like peptide-1 (GLP-1), which is released by the gut after we eat to tell the brain we are full.
The drug activates GLP-1 receptors in the brain which register fullness in the stomach after minimal amounts of food. As a result, people feel full even after half a plate of food.
One of my patients says he always eats his favourite parts of a meal first now he takes Wegovy, in case he gets too full later.
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YOUR DIGESTION SLOWS DOWN
The drug also slows the rate at which food passes through the gut – making people feel full for longer. So whereas it might normally take just five or ten minutes for food that you’ve eaten to leave your stomach – it can take an hour or more on GLP-1 drugs.
But there can be a downside: studies show around one in 100 people on the drugs develop gastroparesis (or stomach paralysis), where stomach muscle contractions become too weak to digest food and pass it on to the intestines; this can cause nausea and vomiting. Around half those who develop gastroparesis also become constipated.
YOU BURN MORE CALORIES
Wegovy also appears to slightly increase the number of calories burned at rest, but why is not fully understood.
HEART HEALTH IMPROVES
Losing significant amounts of weight is obviously good for the heart. But it’s thought Wegovy does something else besides – it reduces inflammation in blood vessels that can clog them up, cutting the risk of a clot forming that can cause a heart attack or a stroke.
A study in the New England Journal of Medicine last year found there were 20 per cent fewer heart attacks, strokes and deaths in overweight or obese patients taking the drugs than in similar patients on a placebo.
What puzzled the researchers was that most patients didn’t reach their maximum weight loss until a year or so into treatment – yet heart attack and stroke rates started to drop within weeks of starting the GLP-1 drugs.
It’s thought the weekly jabs drive down blood sugar and this, in turn, reduces inflammation in blood vessel walls.
These drugs seem to have a direct effect on the heart that reduces the risk of a heart attack.
Wasim Hanif, a professor of diabetology and endocrinology at University Hospital Birmingham, has given a glimpse of the effects of weight-loss drugs
REDUCES YOUR APPETITE FOR ALCOHOL
Some people find Wegovy curbs their desire to drink alcohol. A study at Oklahoma State University, involving 80 heavy drinkers, is looking at what effect weekly injections of semaglutide (the active ingredient in Wegovy) or a dummy drug has on consumption over a 12-week period.
It follows a similar study at Gothenburg University in Sweden last year which found that rats given the drug consumed 60 per cent less alcohol than those not injected with semaglutide.
It’s thought the drug works in a similar way to how it does in obesity – dampening down the ‘reward’ hit that the brain gets when alcohol is consumed and so reducing the urge to keep drinking.
BLOOD SUGAR LEVELS COME DOWN
Although primarily a weight-loss drug, Wegovy – like Ozempic – can significantly reduce blood sugar levels by promoting the release of the hormone insulin from the pancreas.
Insulin takes sugar from the bloodstream into cells to use as energy – reducing the risk of type 2 diabetes.
But at the same time the drugs block the effects of another hormone, glucagon, which is released when you have low blood sugar and tells the liver to start releasing stored sugar and fat to fuel the body.
By controlling the release of both hormones, Wegovy can stabilise blood sugar levels.
MAY LEAD TO UNPLEASANT BURPS
Anecdotal reports from the U.S. – where Wegovy-like drugs for obesity and type 2 diabetes have been in use for much longer than in the UK – suggest some users can develop foul-smelling ‘rotten egg’ burps.
It’s not exactly clear why this happens, but one possibility is Wegovy increases the number of sulphur-producing bacteria in the gut, by altering the microbiome (the community of bacteria, viruses and other microbes that live there), or because food lingers for longer than normal – causing more unpleasant aromas – because the drug slows the gastric-emptying process.
YOU MIGHT AGE MORE QUICKLY
While Wegovy might benefit your waistline, it could have the opposite effect on your face.
There have been reports of accelerated facial ageing – more wrinkles, saggier skin – after a few months on the drug due to the rapid, significant weight loss.
Facial fat smooths out wrinkles and cushions the skin; when it disappears, the skin can appear to be more saggy due to reduced levels of collagen – the fibrous tissue that gives skin its strength and flexibility.
It’s one of things people notice once they have lost about 15 per cent of their body weight.
YOUR LIVER SLIMS DOWN
You won’t necessarily notice it, but injecting Wegovy once a week is likely to be doing your liver the world of good.
That’s because some evidence suggests it also combats fatty liver disease, a build-up of fat around the liver which kills around 10,000 people a year in the UK.
Non-alcoholic fatty liver disease (where fat from diet damages the liver rather than booze) has emerged as major health problem in the UK in recent years and now accounts for a significant number of liver transplants due to sudden liver failure.
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AND YOU FEEL MORE ENERGETIC
Once the excess weight starts to drop off, Wegovy patients start to experience a lot more get-up-and-go.
Energy levels tend to be very low in people who are overweight or obese and that’s partly because oxygen levels in the blood are reduced.
This is thought to be due to the fact that breathing in obese people is affected by the extra weight, reducing the amount of oxygen getting into the bloodstream and increasing levels of carbon dioxide.
People may not notice much difference in the first three months, but once they start to lose weight they tell me their energy levels improve.
WAVE GOODBYE TO SNORING
Heavy snoring is a common complaint among people who are obese.
Excess fat around the neck can put pressure on the airways when someone is lying down asleep and this can lead to a condition called obstructive sleep apnoea – where breathing is repeatedly interrupted every few seconds, jolting people awake and leaving them excessively drowsy during the day. Sleep apnoea is linked with an increased risk of heart attacks.
Wegovy helps by reducing fat around the neck.
EVEN YOUR FINGERS GET SKINNIER
Many find even wrists and fingers can slim down. Last summer social media was full of stories of formerly obese patients seeking modifications to wedding and engagement rings that no longer stayed in position due to their radical weight loss on Wegovy or similar drugs.
Wegovy and similar drugs have sparked concerns over their possible psychological effects in some people
POSSIBLE LINK TO SUICIDAL THOUGHTS?
Ever since Wegovy and similar drugs first emerged, there have been concerns over their possible psychological effects in some people.
In July 2023, the European Medicines Agency revealed it had received 150 reports of patients on the drugs experiencing thoughts about suicide or self-injury.
Shortly afterwards, the Medicines and Healthcare products Regulatory Agency – the body that vets drug safety in the UK – revealed that it, too, had received several similar reports.
But it’s still not clear if the drugs are to blame or whether it’s due to pre-existing conditions in some patients.
A major study by researchers at Case Western Reserve School of Medicine, Cleveland, Ohio – published in the journal Nature last week – looked at the records of 1.8million people who have taken these kinds of drugs and concluded there is no evidence that they are linked with an increase in suicidal thoughts.
Depression can occur in severe weight loss anyway as some patients struggle with not being able to eat what they want any more.