Liraglutide is a prescription medication that manages blood sugar and weight by mimicking the naturally occurring hormone Glucagon-like peptide-1 (GLP-1). It belongs to the class of GLP-1 receptor agonists, initially developed to treat type 2 diabetes. As a synthetic analog, it activates the same receptors, improving metabolic control and promoting satiety through biological pathways.
How Liraglutide Works in the Body
Liraglutide acts as an agonist for the GLP-1 receptor, found in tissues like the pancreas, brain, and gastrointestinal tract. Binding to these receptors affects glucose metabolism in three primary ways. The first is enhancing the release of insulin from the pancreas, but only when blood sugar levels are high (glucose-dependent insulin secretion). This action helps to lower elevated blood glucose without significantly increasing the risk of low blood sugar.
The second mechanism involves suppressing glucagon release. Glucagon is a hormone that signals the liver to produce and release stored glucose into the bloodstream. By reducing glucagon secretion, liraglutide prevents the liver from adding excess sugar to the circulation, especially between meals.
The third effect centers on the digestive system and appetite regulation. Liraglutide slows gastric emptying, which is the rate at which the stomach empties its contents. This delay smooths the rise in blood sugar after eating and contributes to satiety, reducing overall food intake. The molecule is resistant to rapid breakdown, allowing for once-daily dosing.
Approved Uses and Dosage Differences
Liraglutide is approved for two distinct clinical applications, reflected in different brand names and dosages. For type 2 diabetes treatment, it improves blood sugar control in adults and children over 10, often alongside diet and exercise. In adults with established heart disease, it also reduces the risk of major cardiovascular events, such as heart attack and stroke.
The standard maximum dose for type 2 diabetes management is 1.8 milligrams (mg) injected once daily, reached through a gradual increase from a 0.6 mg starting dose. The other primary use is chronic weight management in adults and adolescents over 12 who meet specific body mass index (BMI) requirements. For this indication, the target maintenance dose is significantly higher at 3.0 mg once daily.
This difference highlights that the drug’s effects are dose-dependent, with the 3.0 mg dose approved for sustained weight loss. In both applications, treatment starts with a 0.6 mg dose, which is slowly increased over several weeks. This titration schedule helps patients better tolerate the medication and minimizes gastrointestinal side effects.
Practical Guide to Administration
Liraglutide is administered daily as a subcutaneous injection using a pre-filled pen device. The injection is given just under the skin and can be done at any time of the day, regardless of meal timing. Common injection sites include the abdomen, thigh, or upper arm.
Patients must rotate the specific injection site within the chosen body region for each dose to prevent irritation and tissue changes. Before use, the medication must be visually inspected to ensure the solution is clear, colorless, and free of particles. A new, sterile needle must be used for every injection and removed immediately after delivery.
Proper storage maintains effectiveness: unused pens should be refrigerated (36°F to 46°F). Once in use, a pen can be kept at room temperature but must be discarded 30 days after the first use. If a dose is missed, patients should take the next scheduled dose as usual without doubling the dose.
Navigating Common Side Effects and Warnings
Like all medications, liraglutide can cause side effects, most commonly related to the gastrointestinal system. Nausea is frequently reported, especially when starting the medication or during dose escalation, but this symptom often lessens as the body adjusts. Other common digestive issues include vomiting, diarrhea, and constipation.
Patients must be aware of rare but serious warnings. Liraglutide carries a Boxed Warning regarding the risk of thyroid C-cell tumors, observed in animal studies. Because it is unknown whether this risk translates to humans, the medication is generally not recommended for individuals with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
Acute pancreatitis (inflammation of the pancreas) has also been reported in people taking liraglutide. Symptoms requiring immediate medical attention include severe, persistent abdominal pain that may radiate to the back, accompanied by vomiting or nausea. Persistent vomiting and diarrhea can cause dehydration, which may lead to or worsen kidney problems.