Effect of GLP-1 ana­logues on bodyweight and blood sugar


Claims are being made that diabetes medications like Ozempic containing the GLP-1 agent semaglutide are a new miracle cure for losing weight and combating obesity. But what exactly are GLP-1 receptor agonists, and what effect do they have on our metabolism, diet and blood sugar?

GLP-1: effect of the gut hormone

GLP-1 stands for glucagon-like peptide-1 and is produced in our gut. Our body releases this gut hormone when we eat, which has an effect on our glucose metabolism. GLP-1 promotes the release of insulin from the pancreas and inhibits the hormone glucagon, which is an antagonist of insulin.

GLP-1 prolongs satiety

The gut hormone GLP-1 has a further effect on our digestion in that it delays gastric emptying. This prolongs satiety and reduces our appetite.

Consequences of a GLP-1 deficiency

A deficiency of certain gut hormones, for example GLP-1, can contribute to insulin resistance. As insulin regulates the amount of sugar in the blood, a GLP-1 deficiency is one of the causes of type 2 diabetes. In type 2 diabetes, the body develops a resistance to the effect of the body's own insulin.

GLP-1 medications

GLP-1 medications lower blood sugar and belong to the group of antidiabetics. In technical terms, they are known as GLP-1 receptor agonists or GLP-1 analogues.

GLP-1 receptor agonists: effect

Put simply, GLP-1 receptor agonists mimic the effect of the gut hormone GLP-1. They promote the release of insulin and inhibit the hormone glucagon. GLP-1 analogues also slow down gastric emptying, which means that blood sugar levels rise more slowly and satiety lasts longer. GLP analogues have a longer effect than the body’s natural gut hormone.


There are various agents that belong to the group of GLP-1 receptor agonists. Their use is determined by the effectiveness of the therapy and any accompanying disorders. The agents include:

  • Semaglutide
  • Lixisenatide
  • Liraglutide
  • Albiglutide
  • Dulaglutide

Diabetes treatment with GLP-1 agents

Among the treatments for controlling blood sugar in type 2 diabetes, doctors also use GLP-1 agents. Prescribing GLP-1 receptor agonists is a relatively new form of treatment.

Use of GLP-1 analogues for type 2 diabetes

For patients with type 2 diabetes, medical specialists initially recommend basic therapy. This includes educating the patient, changing their diet, increasing their physical activity and, where necessary, helping them to lose weight and stop smoking. If these actions are not sufficient, doctors usually prescribe blood sugar-lowering medication such as metformin. Another possible treatment involves antidiabetic agents containing GLP-1 receptor agonists.

GLP-1-based diabetes therapies are always administered by injection. Some agents are injected daily, others once a week.

Combination therapy with GLP-1 medications

In some cases, specialists recommend GLP-1 therapy in combination with other antidiabetic medications. For example, a combination of metformin and GLP-1 receptor agonists can be beneficial for type 2 diabetes patients with cardiovascular or kidney disease. Combination therapy with a GLP-1 analogue can also be useful for more severely affected patients who require insulin injections. Practice has shown that this reduces the risk of hypoglycaemia.

Weight reduction with GLP-1 analogues

Doctors also prescribe GLP-1 receptor agonists for patients with type 2 diabetes who are unable to lose weight by conventional means.

Treatment of obesity with GLP-1 agents

Recent research has shown that GLP-1 receptor agonists are also effective in the treatment of obesity. The first GLP-1 analogue to be approved for the treatment of obesity in Switzerland was liraglutide in 2017. GLP-1 medications help with weight loss because they have the effect of delaying gastric emptying which, in turn, reduces the patient’s food intake.

GLP-1 agents for weight loss

Medications with GLP-1 agents are prescription drugs rather than harmless appetite suppressants. But many people are now using diabetes medication like Ozempic containing semaglutide as a replacement to conventional weight-loss diets. These people are not only putting themselves at risk, but are also contributing to medication shortages for diabetics.

Risks and side-effects

Due to the lack of long-term studies, the risks of GLP-1 agents have not been researched in full. Some studies indicate an increased risk of pancreatic inflammation in obese patients without diabetes.

Side effects of GLP-1 receptor agonists

  • Nausea
  • Vomiting
  • Diarrhoea
  • Stomach pain
  • Local reactions at the injection site

Studies on long-term effects are lacking

It is unclear to what extent secondary diseases of obesity, such as type 2 diabetes or cardiovascular diseases, can be prevented by losing weight with GLP-1 medications. There is also only limited experience of the long-term risks of the drugs. Experts see this lack information as critical because therapy with GLP-1 receptor agonists is prescribed for a life-time.

Ozempic babies

Recently, there have been an increasing number of reports of women who have unexpectedly become pregnant during treatment with Ozempic. However, whether the semaglutide agent in the medication has an effect on fertility is not clear. Experts have two hypotheses about an indirect effect:

  1. Obesity has negative effects on fertility. When fat is lost, the menstrual cycle can regulate itself more easily and fertility improves.
  2. Semaglutide, like other GLP-1 receptor agonists, delays gastric emptying. This can diminish the effect of oral contraceptives such as the pill.

Effect on the unborn child

Animal studies have shown that semaglutide can lead to miscarriages and malformations during pregnancy. Although no studies have been con­ducted on humans, the manufacturers recommend that women who wish to have children refrain from taking the agent.


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