Semaglutide: what to expect and when

Starting any medication can be daunting, especially weight loss medications like Wegovy. Many are nervous about what effects to expect and when. In this article, we’ll be discussing how the medication affects your body, when you’ll see results and what side effects you may experience. So, you can learn what’s normal and what’s not so normal.

Semaglutide mechanism Blood sugar levels Appetite Side effects Stopping Wegovy Main takeaways Start a Consultation

Medically reviewed by Dr. Caroline Fontana Written by our editorial team Last reviewed 06-01-2024

How does Semaglutide affect the body?

When understanding the effects of Wegovy, you need to know how the medication works.

Semaglutide is a GLP-1 agonist. It promotes the production of the GLP-1 (glucagon-like peptide 1) hormone by stimulating the GLP-1 receptors in your pancreas.

This has several critical effects on your body.

Pancreas Semaglutide helps your pancreas produce more insulin when your blood sugar is high Liver Semaglutide prevents your liver from making and producing too much sugar. Stomach Semaglutide slows down digestion and the rate which food leaves your body.

How Semaglutide works

Click on one of the organs to see the ways Semaglutide works in your body.

These combined effects help to control your blood sugar, which helps people with diabetes.

It also reduces your appetite in two main ways.

Slowing down your digestion means you feel fuller for longer.
It also helps keep your blood sugar more stable. Blood sugar spikes can cause you to have cravings.

This means you consume fewer calories which result in weight loss. This discovery has led to several GLP-1 agonists being licensed as weight loss drugs, such as Saxenda pens.

The drug was first licensed for type 2 diabetes as it primarily affects blood sugar levels. So, it is one of the first effects to occur. Although, you won’t feel or see a difference without a blood sugar test.

Your blood sugar should start to drop during the first week of taking it. However, Semaglutide is a long-acting medication. Depending on your blood glucose levels before starting it, it can take up to 8 weeks to see the full effect of the medication.

One study Trusted source National Center for Biotechnology Information (NCBI) Government Source Biomedical Research and Literature Go to source compared the effects of Semaglutide and diabetes medication Sitagliptin on blood sugar levels. They found that after 56 weeks, participants’ average blood glucose levels (HbA1c levels) reduced by 1.3-1.6%.

When will my appetite change on Wegovy?

The first positive change you should notice when you start taking Wegovy is your appetite.

Weight loss pen and cartridges in front of measuring tape wrapped around an apple.

Everyone is different, but most people will start to notice a difference in their appetite within the first 4 weeks. Some people may see effects on their appetite as soon as 1 week after their first dose.

How long does it take to lose weight on Wegovy?

Semaglutide is designed to work gradually. This ensures safe and sustainable weight loss, helping you keep the weight off long-term. So, the weight is not going to fall off you in the first week.

In one clinical trial Trusted source National Center for Biotechnology Information (NCBI) Government Source Biomedical Research and Literature Go to source , they found that people started to lose weight after 4 weeks of being on the drug. However, for the majority of people, it will take a bit longer before you see significant differences in your weight.

A series of longer clinical trials provide a better idea of how much weight people lose throughout treatment.

Clinical trial	Study duration	Participants	Semaglutide dose	Results
SUSTAIN-3 Trusted source PubMed Government Source Database of Biomedical Research Go to source	56 weeks	813 type 2 diabetes patients	1mg once weekly	Patients lost on average 5.6 kg (12 lbs).
STEP 1 Trusted source The New England Journal of Medicine Peer-reviewed Journals Medical Research and Review Go to source	68 weeks	1,961 obesity patients	2.4mg once weekly	Patients lost on average 15.3kg (33lbs) - 12.4% of their original body weight.
STEP 5 Trusted source Nature Peer-reviewed Journals Multidisciplinary Research Go to source	104 weeks	304 obesity patients	2.4mg once weekly	Patients lost on average 15.2% of their original body weight.

As you increase the dose over time, you will start to notice the effects.

Why am I not seeing results on Wegovy?

If you are still not seeing significant results after several weeks, you may need to have a look at your lifestyle.

While the medication reduces your appetite, you won’t lose as much weight if you don’t eat healthily and exercise regularly. It’s also an important part of creating lifelong healthy habits.

What should I eat to lose weight?

When should I expect side effects from Semaglutide?

With most medications, it’s common to experience side effects of Wegovy early on in treatment.

Semaglutide side effects most often occur during the first 4 weeks of treatment. So, it’s natural to experience sickness, diarrhoea tiredness and stomach pain at the beginning of your treatment journey.

The most common side effects are mild and should disappear once your body adjusts to the medication.

You may also experience side effects each time you increase your dose. However, the effects will not be as bad or last as long.

However, if your side effects don’t go away or get worse, contact your doctor as soon as possible.

Semaglutide side effects: what you need to know

When should I stop taking Wegovy?

This will be different for everyone and will depend on how much progress you make or how much weight you have to lose.

When you stop taking it will depend on your current body mass index (BMI). Most can stop taking it once they reach a healthy BMI which is between 18.5 - 24.9.

However, if you have not lost at least 5% of your original body weight after 12 weeks of using the maintenance dose, you should stop taking Semaglutide.

Graphic showing a timeline of Semaglutide effects.

Main takeaways

Semaglutide affects the body in many different ways. Your blood sugar levels and appetite will be some of the first changes you’ll notice. It is also likely you will experience side effects in the first few weeks. Weight loss, on the other hand, will be more gradual.

While everyone will be affected at different stages, this is a rough timeline of what to expect. If you’re concerned about any effects of the medication, always consult your doctor.