What is the relationship between Semaglutide (Glucagon-like peptide-1 receptor agonist) and the development of thyroid nodules?

From the Guidelines

Semaglutide is safe for use in patients with thyroid nodules, except for those with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2, as it does not appear to cause or worsen thyroid nodules in most patients. While there were initial concerns about GLP-1 receptor agonists like semaglutide potentially affecting thyroid tissue based on animal studies, human clinical data has been reassuring, as seen in the 2022 study published in Gastroenterology 1. Patients with pre-existing thyroid nodules can generally take semaglutide (Ozempic, Wegovy) without special monitoring beyond routine thyroid care. The medication works primarily by affecting insulin secretion, slowing gastric emptying, and reducing appetite through receptors in the pancreas and brain, with minimal impact on thyroid tissue in humans. However, patients with a personal history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN2) should avoid semaglutide as a precaution, as noted in the 2023 standards of care in diabetes published in Diabetes Care 1. For most patients with common benign thyroid nodules, semaglutide can be used safely while continuing regular thyroid monitoring as recommended by their healthcare provider. If new thyroid symptoms develop while on semaglutide, patients should report these to their doctor, but there's no evidence suggesting the medication increases risk of thyroid problems in humans. Key points to consider include:

• Semaglutide's benefits in weight loss, with a mean weight loss of 10.76% from baseline, as reported in the 2022 study 1
• The potential risks and side effects of semaglutide, including gastrointestinal side effects, pancreatitis, and elevated heart rate, as noted in the 2023 standards of care in diabetes 1
• The importance of regular thyroid monitoring for patients with pre-existing thyroid nodules taking semaglutide
• The contraindication of semaglutide in patients with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2, based on animal studies and noted in both the 2022 study 1 and the 2023 standards of care in diabetes 1

From the FDA Drug Label

In mice and rats, semaglutide caused a dose-dependent and treatment-duration-dependent increase in the incidence of thyroid C-cell tumors (adenomas and carcinomas) after lifetime exposure at clinically relevant plasma exposures It is unknown whether OZEMPIC causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined Patients with thyroid nodules noted on physical examination or neck imaging should also be further evaluated.

Semiglutide and Thyroid Nodules:

• The FDA drug label warns of a potential risk for thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), with the use of semaglutide.
• It is recommended to counsel patients regarding this potential risk and inform them of symptoms of thyroid tumors.
• Patients with thyroid nodules should be further evaluated. 2 2 2

From the Research

Semaglutide and Thyroid Nodules

• The relationship between semaglutide and thyroid nodules is a topic of interest, with several studies investigating the potential link between the two 3, 4, 5, 6, 7.
• A study published in 2021 found that semaglutide induces mostly mild-to-moderate and transient gastrointestinal disturbances, but does not mention a specific link to thyroid nodules 3.
• Another study published in 2023 found that semaglutide use is not associated with an increased risk of thyroid cancer, with an odds ratio of 2.04 (95% CI: 0.33-12.61) compared to placebo 4.
• A review published in 2025 discussed the potential benefits and risks of semaglutide therapy, including the risk of thyroid cancer, but did not provide new evidence on the topic 5.
• A nested case-control analysis published in 2023 found that use of GLP-1 receptor agonists, including semaglutide, for 1-3 years was associated with an increased risk of all thyroid cancer (adjusted HR 1.58,95% CI 1.27-1.95) and medullary thyroid cancer (adjusted HR 1.78,95% CI 1.04-3.05) 6.
• An updated meta-analysis published in 2024 found that semaglutide has a favorable safety profile, with no significant differences in adverse events, including new-onset neoplasm, compared to comparator groups 7.

Key Findings

• The current evidence suggests that semaglutide may not be associated with an increased risk of thyroid cancer 4, but other studies suggest a potential link between GLP-1 receptor agonists and thyroid cancer 6.
• The safety profile of semaglutide is generally favorable, with a low incidence of adverse events 7.
• Further long-term studies are warranted to assess the safety of semaglutide in clinical practice, including its potential impact on thyroid nodules and cancer 4, 7.