Liraglutide vs. semaglutide for weight loss: a head-to-head comparison

Semaglutide and liraglutide belong to a family of GLP-1 (glucagon-like peptide-1) receptor agonists. They mimic the action of the GLP-1 hormone, a natural hormone produced by the body after eating, stimulate the release of insulin, and slow down gastric emptying.

GLP-1 medications have recently gained traction due to their ability to regulate blood sugar levels and promote weight loss. According to KFF surgery data, about 1 in 8 individuals in the United States has used GLP-1 medications during their life and currently, approximately 15 million adults (or 6% of the population) are using prescription drugs for weight loss, type 2 diabetes, or lowering the risk of cardiovascular diseases.

Novo Nordisk produces semaglutide under the brand names Ozempic, Wegovy, and Rybelsus. Liraglutide is also made by Novo Nordisk with the brand names Saxenda and Victoza. Both drugs are approved by the U.S. Food and Drug Administration (FDA) for weight loss (Wegovy and Saxenda) and type 2 diabetes (Ozempic, Rybelsus, Victoza).

Although semaglutide and liraglutide are both GLP-1 medications, there are some key differences between them including their effectiveness for weight loss, blood sugar control, and administration. Semaglutide injections are administered once weekly and liraglutide injections are administered once daily. Semaglutide has proven to be more effective than liraglutide for weight loss and blood sugar control.

Keep reading for a detailed comparison of liraglutide and semaglutide, highlighting their similarities, differences, and factors to consider when choosing the right medication.

What is liraglutide?

Liraglutide is a glucagon-like peptide-1 receptor agonist. GLP-1 is a natural hormone secreted after eating food. This hormone is responsible for appetite suppression and a feeling of fullness or satiety. Liraglutide imitates the action of GLP-1 hormones, occupies its receptors, and affects the areas of the brain that control hunger. This way, liraglutide promotes blood sugar control and weight loss. Liraglutide is FDA-approved for the management of type 2 diabetes (Victoza) and weight loss (Saxenda).

A clinical study shows that liraglutide significantly reduced HbA1c within 6 months of starting the medication. 16.9-47% of patients met the NICE composite endpoint (weight reduction of 3% or greater and HbA1c reduction of 1% or greater). The weight and glycemic control were maintained for at least twelve months after the medication.

The SCALE Diabetes Randomized Clinical Trial showed weight loss of 6% with liraglutide 3 mg dose, 4.7% with 1.8 mg dose, and 2% with the placebo over 56 weeks.

Liraglutide has also been shown to provide cardiovascular benefits including lowering the risk of major cardiovascular events.

The manufacturer, Novo Nordisk, produces liraglutide with the brand names Victoza and Saxenda, which have an estimated half-life of 13 to 15 hours and are therefore injected once daily.

Victoza

Victoza is FDA-approved for improving blood sugar control in adults and children aged 10 years or more with type 2 diabetes when paired with increased physical activity and dietary modifications. It is not used for patients with type 1 diabetes. It comes in the form of injections that are administered daily under the skin (subcutaneously). Each Victoza pen (18mg/3ml) has 18mg of liraglutide in 3ml.

Saxenda

Saxenda is FDA-approved for chronic weight management when used as an adjunct to dietary modifications and increased physical activity in patients aged 12 or more with:

• Obesity, with BMI that cuts off for sex and age and corresponds to a body mass index equal to or greater than 30 or more for adults
• Body weight greater than 132 pounds (or 60 kg).

Saxenda is injected subcutaneously once daily. Its dosage starts at 0.6mg once daily, which your healthcare provider increases afterwards.

How liraglutide works

Liraglutide mimics the action of a natural hormone, glucagon-like peptide-1, that controls hunger cravings and appetite. The medication suppresses appetite, makes you feel full, and delays the rate at which the stomach empties. By reducing appetite, liraglutide manages blood glucose levels in type 2 diabetes and promotes weight loss.

What is semaglutide?

Semaglutide is a GLP-1 medication made by Novo Nordisk. It occupies the GLP-1 receptors in the brain to suppress appetite and delay gastric emptying. Currently, the manufacturer produces semaglutide with three brand names: Ozempic, Wegovy, and Rybelsus. Semaglutide injections have a half-life of about 7 days and are injected once weekly.

Wegovy is FDA-approved for promoting weight loss in obese and overweight patients and managing the risk of cardiovascular events in such patients, while Ozempic and Rybelsus are indicated for patients with type 2 diabetes.

A clinical study compared weight loss of semaglutide vs. placebo. The semaglutide group reduced 14.9% from their baseline body weight compared to 2.4% with the placebo group. The STEP 1 trial also showed significant results with blood sugar control, with 84.1% of participants receiving once-weekly semaglutide 2.4 mg having normoglycemia at week 68. Semaglutide has also shown cardiovascular benefits and helps to reduce the risk of adverse cardiovascular events in people with diabetes.

Ozempic

Ozempic is injected once weekly under the skin, just above your muscles (subcutaneously). Ozempic was initially FDA-approved for promoting blood sugar control in adults with type 2 diabetes when combined with exercise and dietary modifications. On January 29, 2025, the FDA approved Ozempic for reducing the risk of worsening kidney disease and cardiovascular deaths in adults with type 2 diabetes.

Ozempic is also used as an off-label medication for weight loss. The FDA has not yet approved Ozempic for chronic weight management.

Wegovy

Wegovy is a once-weekly injection that is injected subcutaneously (under the skin). The dosage strength is typically escalated every four weeks depending on the patient’s tolerance. Wegovy is FDA-approved for promoting weight loss and reducing the risk of cardiovascular problems such as heart attack, stroke, and cardiovascular death in patients with obesity and overweight when paired with lifestyle modifications such as low-calorie diet and exercise.

Rybelsus

Rybelsus is the first GLP-1 receptor that comes in the form of oral tablets. It is FDA-approved for managing blood sugar levels in patients with type 2 diabetes as an adjunct to dietary changes and increased physical activity.

How semaglutide works

Semaglutide works for weight loss and diabetes the following ways:

• Targets GLP-1 receptors to reduce the feeling of hunger
• Slows down stomach emptying to give you a feeling of fullness for a longer time
• Reduces craving for fatty foods and binge eating
• Increases the levels of free leptin and decreases ghrelin levels to promote weight loss

Similarities

Semaglutide and liraglutide belong to the same class of medication (GLP-1 agonists) and share a few similarities:

Mechanism of action

Both medications belong to a class of GLP-1 receptor agonists. They work by mimicking the action of glucagon-like peptide-1 to suppress appetite, delay stomach emptying, and reduce craving for certain foods.

Benefits

Semaglutide and liraglutide share a few common benefits, such as:

• Both drugs promote blood sugar control in patients with type 2 diabetes
• Semaglutide (Wegovy) and liraglutide (Saxenda) help reduce body weight in obese and overweight patients
• Both drugs have potential cardiovascular benefits and reduce the risk of heart attack, stroke, and cardiovascular death

Side effects

As semaglutide and liraglutide belong to the same class of drugs (GLP-1 receptor agonist), they have common side effects such as nausea, vomiting, diarrhea, constipation, stomach pain, injection site reaction, and pancreatitis.

Liraglutide vs. semaglutide: Key difference

Although semaglutide and liraglutide belong to the same class of medications and share similarities in mechanism of action, benefits, and side effects, they differ in efficacy, dosage strength, frequency, safety profile, cost and availability.

Efficacy for diabetes and weight loss

SUSTAIN 10 compared the efficacy of semaglutide (1.0 mg) with liraglutide (1.2 mg). Semaglutide reduced mean HbA1c by 1.7% compared to 1.0% with liraglutide. Semaglutide was superior to liraglutide in managing body weight and reducing HbA1c.

The step 8 clinical trial compared the effect of weekly subcutaneous semaglutide vs liraglutide (daily) in obese and overweight patients without type 2 diabetes. The study involved 338 individuals. The semaglutide group showed a mean weight change of 15.8% compared to 6.4% in the liraglutide group. The study concludes semaglutide has significantly greater efficacy than liraglutide when combined with a healthy lifestyle and increased physical activity.

Dosage and frequency

Semaglutide injections (Wegovy and Ozempic) are injected once a week. In contrast, liraglutide is injected daily. Semaglutide is also available as oral tablets with the brand name Rybelsus, which are taken daily.

The dose of semaglutide injections (Wegovy and Ozempic) starts from 0.25 mg weekly for the first four weeks and escalated to 0.5 mg weekly for the next four weeks. If tolerated, the dose is increased to 1 mg weekly for the next 4 weeks. If the patient can tolerate it, the dose is escalated to 1.7 mg (Wegovy) or 2 mg weekly (Ozempic) for the next four weeks and up to a maximum of 2.4 mg once weekly (Wegovy) afterwards as a maintenance dose.

Rybelsus is available with dose strengths of 3 mg, 7 mg, and 14 mg. Its dosage starts from 3 mg once daily for 30 days, which escalates to 7 mg for the next 30 days. If the patient needs additional glycemic reduction, it can be increased to 14 mg once daily.

Saxenda dosage starts from 0.6 mg subcutaneous injection once a day for the first week and increases to 1.2 mg, 1.8 mg, and 2.4 mg in the second, third and fourth week, respectively, if the patient can tolerate it. It can be escalated to 3 mg/day from the fifth week if tolerated by the patient, which is the maximum dose.

Victoza (18mg/3ml) dosage starts with 0.6 mg subcutaneous injection per day for at least 1 week. It is escalated to 1.2 mg once daily in the next week and 1.8mg once daily onwards for further glycemic control.

Administration

Liraglutide is available in the form of injections only. It is injected subcutaneously under the skin of the arm, thighs, or abdomen.

In contrast, semaglutide comes in the form of injections and oral tablets. Ozempic and Wegovy are injected subcutaneously, while Rybelsus is available in the form of oral tablets.

Side effects

Common side effects of semaglutide and liraglutide include diarrhea, constipation, nausea, vomiting, loss of appetite, indigestion, low blood sugar levels and stomach problems. Both medications share similar side effects. Although there is a very low incidence of side effects, oral semaglutide may exhibit greater side effects.

A research study demonstrated that oral semaglutide (14mg) has more side effects than 1.2 mg subcutaneous liraglutide. However, no difference was observed when semaglutide and liraglutide were injected subcutaneously. Additionally, semaglutide is linked to a greater risk of cholelithiasis.

Cost and availability

Victoza (liraglutide) costs $543.51 for 0.6 mg and 1.2 mg doses and $815.27 for 1.8 mg doses. 3mg of Saxenda costs around $1,349 for five pen packages. In comparison, Wegovy costs approximately $1,300 and Ozempic costs approximately $1,000 for a 1-monthly supply.

These out-of-pocket costs make it difficult for a few individuals to get these medications without insurance. Fortunately, Novo Nordisk offers a patient assistance program for Ozempic Victoza and Rybelsus, and saving card programs for eligible candidates:

• Ozempic saving card: Pay as little as $25 for a 1-month, 2-month, or 3-month supply if enrolled in commercial insurance with coverage for Ozempic.
• Rybelsus saving card: Pay as little as $10 for a 1-month, 2-month, or 3-month supply if enrolled in commercial insurance with coverage for Rybelsus.
• Wegovy co-pay saving card: Pay as little as $0 for a 1-month, 2-month, or 3-month supply if enrolled in commercial insurance with coverage for Wegovy. Uninsured patients or those without coverage for Wegovy can pay $650 for a 1-month supply.
• Saxenda saving card: Pay as little as $25 for a 1-month, 2-month, or 3-month supply if enrolled in commercial insurance with coverage for Saxenda.

Insurance companies usually cover GLP-1 medications if you take them for treating type 2 diabetes. However, most insurance companies do not cover these medications if they are prescribed for weight loss, such as Wegovy, Saxenda or Ozempic (off-label). You must verify the coverage details from your insurance company before starting any medication.

Safety profile

A systematic review of the efficacy and safety of liraglutide vs semaglutide demonstrates that semaglutide 2.4 mg is the most effective for weight loss and lowering HbA1c, but it also has the highest risk of side effects, including hypoglycemia. Liraglutide 3.0 mg, although less effective than semaglutide 2.4 mg, still has the highest rate of serious side effects. In terms of safety, the overall rate of adverse events was highest with semaglutide 2.4 mg, followed by liraglutide 3.0 mg, liraglutide 1.8 mg, and semaglutide 1.0m g, compared to placebo.

For serious adverse events, the incidence of adverse effects was highest with liraglutide 3.0 mg, followed by liraglutide 1.8 mg, semaglutide 2.4 mg, and semaglutide 1.0 mg. Regarding hypoglycemic events, semaglutide 2.4 mg had the highest rate, followed by liraglutide 3.0 mg, semaglutide 1.0 mg, and liraglutide 1.8 mg.

However, considering cardiovascular benefits, metabolic improvements and low risk of side effects with GLP-1 medications, semaglutide has a favorable risk and benefits ratio, and is considered safer than other medications.

FDA-approved semaglutide and liraglutide are safe for patients. However, FDA has received multiple reports of adverse events with unapproved drugs such as some versions of compounded semaglutide and tirzepatide.

Who should use liraglutide or semaglutide?

Victoza is indicated for children aged 10 and older and adults with type 2 diabetes. Saxenda is suitable for patients who are:

• Overweight (BMI equal to greater than 27) with at least one weight-related medical problem such as high cholesterol levels, hypertension, and type 2 diabetes
• Obese (BMI equal to or greater than 30)

It is also indicated for children aged 12 or more with a body weight above 60 kg or 132 pounds.

Wegovy is indicated for adults who are overweight and obese and those with a higher risk of developing cardiovascular diseases.

Ozempic and Rybelsus are used for adult patients with type 2 diabetes. Recently, Ozempic has been approved for patients with type 2 diabetes to reduce the risk of worsening kidney disease and cardiovascular death.

Wegovy and Ozempic are preferred drugs for those with type 2 diabetes and obesity or overweight, as they’re most effective at controlling blood sugar levels and promoting weight loss.

Factors to consider

While choosing the right medication, you can consider the following factors:

• Individual treatment goals: Semaglutide outperforms liraglutide in weight loss and diabetes management due to its longer half-life and efficacy as demonstrated in clinical trials.
• Medical history: Inform your healthcare provider about your medical history, such as which medications you have been taking, your history of allergies, and your co-morbid conditions. They will help you make the right choice.
• Preferences for administration method: Semaglutide comes in weekly injectable (Wegovy and Ozempic) and daily oral (Rybelsus) forms. In contrast, liraglutide is available only in the form of daily injections. Semaglutide injections are administered once weekly compared to daily liraglutide injections. When choosing a GLP-1 drug, you can discuss with your doctor whether you want to use an injectable or oral medication and whether you want to use a daily or weekly injection.
• Cost and insurance coverage: GLP-1 drugs are typically covered by insurance if they are indicated for type 2 diabetes. Most insurance companies don’t cover weight loss medications. You can compare the costs of each medication with and without insurance coverage to make the right decision.
• Potential side effects: If you are allergic to a specific ingredient in any medication or experience side effects, inform your healthcare provider. They will adjust the dosage or switch to another class of drugs.

Before making a decision, you need to discuss these factors with a healthcare professional to determine the best choice. They will assess your medical history, BMI, blood sugar levels, HbA1c, and vital statistics to make a customized treatment plan for you.

Liraglutide and semaglutide for weight loss

A clinical study discovered that semaglutide has a greater half-life than liraglutide. Semaglutide has a half-life of 165 hours compared to 13-15 hours of liraglutide. This means semaglutide stays in your body to suppress appetite and gives you a feeling of fullness for a longer period compared to liraglutide. It shows semaglutide is more effective for weight loss than liraglutide.

A phase 2 clinical trial compared the effect of semaglutide (0.4 mg) vs liraglutide (3.0 mg). Semaglutide promoted significantly more weight loss than liraglutide.

Saxenda and Wegovy are indicated particularly for weight loss. A study compared the effects of Saxenda and Wegovy on weight loss, and patients who used Wegovy lost 15.85% of their weight, while the Saxenda group lost 6.4% of their body weight.

Liraglutide and semaglutide for type 2 diabetes

Ozempic, Rybelsus (semaglutide) and Victoza (liraglutide) are indicated for managing type 2 diabetes. Studies show that Ozempic is more effective in managing blood sugar levels and reducing A1c than Victoza.

A clinical study involved 577 adults to compare the effect of once weekly 1 mg of Ozempic injection and 1.2 mg liraglutide daily as an add-on to 1-3 oral anti-diabetic drugs. Ozempic reduced mean HbA1c by 1.7%, while liraglutide showed a difference of only 1%. Both drugs had similar side effects, except for gastrointestinal problems that were more frequent in the Ozempic group.

Frequently asked questions

Is semaglutide more effective than liraglutide for weight loss?

Yes, semaglutide is more effective for weight loss than liraglutide because semaglutide has a greater half-life than liraglutide. This means it stays in your body and exerts its action (to suppress appetite) for a longer time, which helps with weight loss.

Can liraglutide or semaglutide be used for Type 1 Diabetes?

No, liraglutide and semaglutide are not indicated for patients with type 1 diabetes.

Are there any long-term risks?

GLP-1 medications usually have a mild to moderate risk of developing side effects. Long-term risks of semaglutide and liraglutide include gastrointestinal problems, pancreatitis, personality changes (such as Ozempic personality), depression, suicidal thoughts, gall bladder problems, and kidney injury. The risk of thyroid cancer (medullary cell carcinoma) is rare. However, it is not recommended to take these medications if you have a family history of thyroid tumor or MEN 2 syndrome.

Which drug is safer for long-term use?

Semaglutide is comparatively safer than liraglutide for long-term use. A randomized clinical trial shows that only 13% of people discontinued semaglutide compared to 27.6% for liraglutide in a 68-week trial. Patients had a greater tendency to stick to semaglutide therapy. Moreover, semaglutide outperformed liraglutide in safety and efficacy.

How do I avoid or minimize side effects?

To minimize the side effects, escalate the dose of GLP-1 agonist slowly as recommended by your healthcare provider and follow the diet plan provided by your dietician. Higher doses can lead to adverse effects. Stay in touch with your healthcare provider for continuous monitoring. If your body tolerates a certain dose, your doctor will escalate it accordingly.

Which medication has fewer side effects?

Semaglutide appears to have fewer side effects than liraglutide due to less frequent dosing and a higher level of tolerance among patients. A systematic review demonstrates that semaglutide can cause hypoglycemia, but liraglutide is associated with a higher incidence of serious side effects.

Can I take liraglutide and semaglutide together?

No, you can not take semaglutide and liraglutide together. Both of these medications have the same mechanism of action. Taking both medications together can affect your blood sugar levels, leading to low blood sugar levels (hypoglycemia). Taking these medications together also increases the risk of side effects.

How do I switch from liraglutide to semaglutide or vice versa?

Yes, you can switch from liraglutide to semaglutide and vice versa. You should consult your healthcare provider first to discuss how to safely switch between medications. They will adjust your treatment plan accordingly. You can start semaglutide after one day of stopping liraglutide.

If you switch from semaglutide to liraglutide, you have to wait for at least one week to start with liraglutide.

How to maximize the benefits of weight loss drugs

To maximize the benefits of weight loss medications, use them in combination with a healthy diet and increased physical activity, as recommended by the FDA.

1. Healthy diet

Follow a diet plan to achieve maximum weight loss results. Add more fruits, vegetables, and lean proteins to your diet. Avoid taking high-calorie foods such as sugary snacks, fatty meals, sodas, processed foods, starchy vegetables, refined carbohydrates and grains, and carbonated drinks.

2. Increased physical activity

Add exercises such as strength training, light cardio, and yoga to complement the effect of weight loss medications. Regular physical activity burns extra calories, supports cardiovascular health, lowers cholesterol levels and promotes weight loss.

Bottom line: which one is right for you?

Although semaglutide and liraglutide belong to the same class of drugs, GLP-1 receptor agonists, they differ in efficacy, indications, safety profile, route of administration, and dosing schedules. Semaglutide has a higher efficacy and safety profile than liraglutide. It promotes greater weight reduction and glycemic control, as indicated by clinical trials. Liraglutide is only available in injectable form. In contrast, semaglutide offers injectable (Ozempic and Wegovy) and oral (Rybelsus) formulations. Liraglutide is injected daily compared to once weekly semaglutide (Wegovy and Ozempic) injections.

The choice of the right medication depends on the patient’s goals, medical history, preference for methods of administration, tolerance, insurance coverage and the cost of medication. Before starting a medication, consult your healthcare provider to discuss your choice and concerns. They will create a customized treatment plan according to your needs. In case of any side effects, stop taking the medication and consult a healthcare professional immediately.