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Does Januvia cause weight gain or loss?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on May 9, 2025.

Official Answer by Drugs.com

Key Points

What do Januvia studies say about weight gain or loss?

Compared to placebo

In two Phase III, 18 or 24 week, placebo controlled studies with 1262 patients with type 2 diabetes, the majority of those who received Januvia given by itself (monotherapy) did not gain weight, compared to a small decrease in weight with the placebo group.

In combination with metformin

Januvia may be frequently used in combination with other medicines for type 2 diabetes. Your doctor will determine your need for combination therapy based on your overall goals for treatment.

When used with metformin in studies, the decrease in body weight in the groups given Januvia plus metformin was similar to those given metformin alone.

Table 1: Weight loss for Januvia plus metformin compared to metformin alone

Mean change from baseline at 24 weeks
*Table adapted from manufacturer’s data
Januvia + metformin Weight loss of 0.6 kg to 1.3 kg (1.3 lb to 2.9 lb)
Metformin alone Weight loss of 0.6 kg to 1.3 kg (1.3 lb to 2.9 lb)

Sitagliptin (Januvia) is also approved for use in combination with metformin for treatment of type 2 diabetes. These products are known as Janumet and Janumet XR.

Compared to glipizide

When compared with the sulfonylureas glipizide, patients treated with Januvia plus metformin over 52-weeks had a significant mean body weight loss from baseline compared to a significant weight gain in patients administered glipizide (Glucotrol).

Table 2: Weight loss for Januvia compared to glipizide

Weight change at 52 weeks
*Table adapted from manufacturer’s data
Januvia + metformin Weight loss of 1.5 kg (3.8 lb)
Glipizide + metformin Weight gain of 1.1 kg (2.4 lb)

In combination with glimepiride

In studies, when Januvia was added to treatment with the sulfonylureas glimepiride (Amaryl), patients treated with Januvia had a weight increase.

Table 3: Weight changes when Januvia + metformin added to glimepiride

Weight change at 24 weeks
*Table adapted from manufacturer’s data
Januvia + metformin + glimepiride Weight gain of 0.8 kg (1.8 lb)
Placebo + metformin + glimepiride Weight loss of 0.4 kg (0.8 lb)

In combination with insulin

In studies, when Januvia was added to treatment with insulin injection, patients treated with Januvia had similar weight changes when compared to placebo.

Table 4: Weight changes when Januvia added to insulin

Weight change at 24 weeks
*Table adapted from manufacturer’s data
Januvia + metformin + insulin Weight gain of 0.09 kg (0.2 lb)
Placebo + metformin + insulin Weight gain of 0.09 kg (0.2 lb)

Related questions

What is Januvia used for?

Januvia (generic name: sitagliptin) is a prescription medication used in addition to diet and exercise to improve your blood glucose (blood sugar) control in adults living with type 2 diabetes. Januvia is an oral tablet that is taken once a day, with or without food.

It is taken once a day and is used in addition to diet and exercise to improve your blood sugar control (measured by an A1C blood test).

In research studies of people with type 2 diabetes, Januvia significantly improved hemoglobin A1C, fasting plasma glucose and 2-hour postprandial glucose., all measures of blood sugar control. Left untreated, type 2 diabetes can cause serious medical problems such as nerve and kidney damage, vision problems, and heart disease.

Januvia is not for treating type 1 diabetes or diabetic ketoacidosis (increased ketones in your blood or urine).

Is Januvia used for weight loss in patients without diabetes?

Januvia is only approved for the treatment of type 2 diabetes. It is not approved by the FDA to be used specifically for weight loss. More studies are needed to determine if Januvia can be used safely for weight loss in patients without type 2 diabetes.

A small, three month study in 70 patients evaluated the use of Januvia in patients without type 2 diabetes.

Is weight loss a side effect with Janivia?

The manufacturer does not list weight loss as a side effect for Januvia. In general, Januvia is usually well-tolerated.

However, most drugs, including Januvia have side effects and come with some level of risk. It is also important to remember the risk from untreated type 2 diabetes can also negatively impact your health. Left untreated, type 2 diabetes can cause serious medical problems such as nerve and kidney damage, vision problems, and heart disease. Talk with your doctor about the risk from side effects with Januvia, and how to recognize them.

Common side effects with Januvia (occuring in >5% of patients):

Serious side effects with Januvia may include:

A serious skin reaction called a bullous pemphigoid can occur with DPP-4 inhibitors such as Januvia. Call your doctor immediately if you develop blisters or the breakdown of the outer layer of your skin (erosion). You may need to stop taking Januvia.

This is not all the information you need to know about Januvia for safe and effective use. Review the full Januvia information here, and speak to your health care provider if you have questions or concerns.

Bottom Line

Januvia (sitagliptin) is a type 2 diabetes medicine that can help you lower your blood sugar and reach your target goals, when used with diet and exercise. In studies it has not been shown to lead to weight gain when used alone or with metformin.

Januvia is not approved to be used for weight loss. More study is needed in this area to safely recommend this use in patients without type 2 diabetes.

Weight loss is not listed as a side effect with Januvia in product information, although you may lose weight if you are taking it. In patients with type 2 diabetes, weight loss is usually a beneficial effect for most patients.

References

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