The influx of weight loss drugs and their consequent rise in popularity has led to a variety of options on the market. The wide selection can get confusing, with some drugs having additional indications, different brand names, and different dosages. Additionally, some drugs may be used off-label for weight loss or may not be indicated for weight loss at all, though they show effects in the realm of chronic weight management.

One such drug that you may have heard of is Januvia, also known as sitagliptin. Januvia is approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes. Many other drugs on the market for type 2 diabetes, like semaglutide (e.g., Ozempic, Wegovy), are also known to induce significant weight loss. Can other antidiabetic agents, like Januvia, do the same? There is some research out there that has attempted to clarify this point. Thus, in this article, we discuss Januvia and its potential for weight loss.

What is Januvia used for?

Januvia, containing the active ingredient sitagliptin, is indicated for the treatment of blood sugar management in individuals with type 2 diabetes in adjunct to diet and exercise. Diabetes is a condition affecting as many as 38 million people in the US, amounting to roughly 10 percent of the population. Of these individuals, roughly 90 to 95 percent of them have type 2 diabetes. Type 2 diabetes typically develops in individuals over the age of 45, however, more and more children and adolescents are getting type 2 diabetes every year.

The mechanisms underlying type 2 diabetes involve insulin. Insulin is a hormone produced by the pancreas which contributes to blood sugar regulation. With type 2 diabetes, the body’s response to insulin is dysfunctional, leading to insulin resistance. Thus, the body cannot properly control blood sugar levels, leading to high levels. High blood sugar levels for a prolonged period causes prediabetes and diabetes, which have several complications. Diabetes can cause cardiovascular, nerve, ear, and eye damage down the line, many of these complications being potentially fatal.

There are several medications, treatments, and lifestyle modifications that can help people to manage their diabetes. One such medication class are dipeptidyl peptidase 4 (DPP-4) inhibitors, from which the medication Januvia belongs.

How does Januvia work?

As aforementioned, Januvia (sitagliptin) is a DPP-4 inhibitor. But, how exactly does this type of medication help with diabetes? Well, DPP-4 is an enzyme in the body that is involved with glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP) hormones. GLP-1 works by lowering blood glucose levels by activating insulin production, slowing gastric emptying, and lowering glucagon concentrations. There are several medications on the market that act directly on GLP-1 receptors (e.g., Ozempic) or both GLP-1 and GIP receptors (e.g., Mounjaro). However, sitagliptin helps regulate these hormones indirectly.

DPP-4 normally breaks down GLP-1 and GIP hormones. However, when DPP-4 is inhibited by sitagliptin, GLP-1 and GIP are not broken down and thus their levels increase. As a result, more insulin is produced by the pancreas, lowering blood sugar levels as a result.

Can Januvia be used for weight loss?

There are some similarities between the mechanisms of Januvia versus other weight loss medications such as Ozempic and Mounjaro. For example, because Januvia works as a DPP-4 inhibitor, it has downstream effects on GLP-1. GLP-1 is implicated in the delay of gastric emptying, which means it slows down the rate in which food moves through your digestive tract. As a result, GLP-1 agonists like Ozempic help individuals to feel fuller for longer, causing them to eat less food and lose weight in the process.

Because Januvia can affect GLP-1, you may be wondering if you can expect to see some weight loss effects when using Januvia. The short answer is possibly, but results are mixed. There are some studies that have evaluated the effects of Januvia on weight. Let’s review some of the research.

Weight loss research with Januvia

One meta-analysis reviewed all clinical trials that have evaluated Januvia in obese or overweight adult individuals that had type 2 diabetes. This meta-analysis analyzed how sitagliptin monotherapy compared to a sitagliptin plus metformin regimen with regards to weight loss. This analysis ended up including 18 randomized controlled trials, totaling to 2,009 subjects included in the study. Results indicated that individuals experienced weight loss with both sitagliptin alone and the sitagliptin plus metformin regimen after a period of six months. The average difference in body mass index (BMI) for the sitagliptin group was -0.23, while the average difference in BMI for the sitagliptin plus metformin group was -0.52.

Another study evaluated sitagliptin’s effects on patients with type 2 diabetes, particularly with regards to blood sugar measurements and other parameters, like weight. After 12 weeks, sitagliptin induced an average weight loss from 80.21 kg baseline to 71.4 kg. The study also demonstrated that sitagliptin caused reductions in blood pressure, lipid parameters, and blood sugar. Other research has compared sitagliptin to other agents with regards to weight loss, including:

  • Glipizide. Sitagliptin and metformin caused a weight loss of 1.5 kg versus 1.1 kg with glipizide and metformin.
  • Glimepiride. Sitagliptin, metformin, and glimepiride caused weight gain of 0.8 kg versus weight loss of 0.5 kg with placebo, metformin, and glimepiride.
  • Insulin. Sitagliptin, metformin, and insulin caused weight gain of 0.09 kg, which was similar to weight gain with placebo, metformin, and insulin of 0.09 kg.

From these studies, it is unclear exactly what the weight loss effects of Januvia might be. Some studies show that it supports weight loss, while others demonstrate little effect or a small gain in weight. Thus, results may vary from individual to individual.

What other effects can I expect from Januvia?

In addition to potentially seeing small reductions in weight, Januvia can also cause a few side effects. The most commonly experience side effect with Januvia is headaches, which occurs in more than one percent of individuals. Other common side effects include body and muscle aches, fever, cough, sneezing, sore throat, ear congestion, breathing difficulties, stuffy nose, sneezing, pain, and loss of voice. Other more serious, but rare side effects, include:

  • Hypoglycemia. Hypoglycemia refers to low blood sugar. Although the goal with antidiabetic treatment is to lower blood sugar, we don’t want it to get too low, as this can be dangerous. Signs of low blood sugar include confusion, feeling hungry, shaking, trouble concentrating, and sweating.
  • Allergic reaction. Allergy can occur with Januvia. Severe allergic reaction, referred to as anaphylaxis, is serious and requires emergency medical attention.

Is Januvia the best option for weight loss?

It is important to note that Januvia is only approved for type 2 diabetes, not weight loss. Although it may cause some modest reductions in weight, it is not meant for this treatment. Additionally, weight loss is not listed as a side effect of Januvia. So, what options are there for weight loss?

There are several different medications on the market for chronic weight management, many gaining popularity in recent years like Ozempic and Mounjaro. Currently available weight loss options include:

  • Semaglutide. Semaglutide, widely known by its brand names Ozempic and Wegovy, is a GLP-1 agonist. It is indicated for both diabetes and weight loss, with very potent and robust weight loss effects being seen in clinical trials.
  • Liraglutide. Liraglutide (Saxenda) is yet another GLP-1 agonist. Given as a once daily injection, it can cause up to five to ten percent reductions in body weight, specifically at its higher dose.
  • Tirzepatide. Tirzepatide is a new medication that combines a powerful dual mechanism. It is both a GLP-1 and GIP receptor agonist, which together promote insulin production and slow gastric emptying.
  • Phentermine. Phentermine is one of the older weight loss medications on the market. It has been shown to cause as much as five percent decreases in body weight.
  • Phentermine-topiramate. Phentermine can also be given together with topiramate. This combination is marketed under the brand name Qsymia, which can induce decreases of five to ten percent of one’s body weight.
  • Naltrexone-bupropion. This medication combines antidepressant effects with an opioid receptor agonist. Together, this can cause weight loss of five to ten percent.
  • Orlistat. Orlistat is a medication known as a lipase. It works by inhibiting an enzyme key to fat breakdown, thus preventing absorption of fat from your diet. Research shows it can cause weight loss of around five percent.


It’s no secret that Januvia can be a great option for the treatment of type 2 diabetes, but there is research out there indicating it may do more than just that. Studies have demonstrated mixed results, showing that Januvia may cause modest weight reductions comparatively to other antidiabetic agents. Other research conclusions are a bit more unclear, showing no difference in weight at all.

Based on this data, if you are starting Januvia for diabetes, know that you may be surprised to see some weight loss along the way. However, there are several other medication options available on the market that are indicated for both diabetes management and weight loss or just weight loss alone. Discuss with your doctor what treatment may be the best option for you depending on your health goals.