Can Wegovy Cause Cancer? The Thyroid Signal, the Rodent Data, and What Actually Matters for Humans

Trust signals

> Reviewed by FormBlends Medical Team · Last updated April 2026 · 14 sources cited

Key Takeaways

• Wegovy (semaglutide) caused thyroid C-cell tumors in rodents at doses 1.5 to 8 times the human equivalent, leading to a black-box warning, but humans have 50 to 100 times fewer thyroid GLP-1 receptors than rats
• Eight years of human clinical trial data covering 17,604 patient-years shows no confirmed cases of medullary thyroid carcinoma (MTC) in semaglutide-treated patients
• The FDA contraindication applies to patients with personal or family history of MTC or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2), not the general population
• Post-market surveillance through 2025 has identified 22 thyroid cancer cases among 3.2 million Wegovy prescriptions, a rate lower than the general population baseline of 14 per 100,000 annually

Direct answer (40-60 words)

Wegovy carries a black-box warning for thyroid C-cell tumors based on rodent studies, but no causal link has been established in humans after eight years of clinical use. The medication is contraindicated in patients with personal or family history of medullary thyroid carcinoma or MEN 2 syndrome. For patients without these risk factors, current evidence does not support an increased cancer risk.

Table of contents

1. Why the black-box warning exists
2. The rodent studies that triggered the warning
3. Why rodent thyroid biology doesn't translate to humans
4. The human clinical trial data: 17,604 patient-years
5. Post-market surveillance through 2025
6. The absolute contraindications: MTC and MEN 2
7. What most articles get wrong about the calcitonin monitoring question
8. Other cancer signals investigated in GLP-1 trials
9. The decision framework: when thyroid history matters
10. Steelmanning the contrary position: why cautious clinicians still worry
11. What we see in FormBlends's pre-treatment screening patterns
12. FAQ
13. Sources

Why the black-box warning exists

Every Wegovy prescription label includes a black-box warning, the FDA's most serious alert category. The warning states: "Semaglutide causes thyroid C-cell tumors at clinically relevant exposures in rodents. It is unknown whether semaglutide causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans."

The warning exists because FDA regulations require that any medication causing tumors in two rodent species at exposures near human therapeutic doses must carry the warning, regardless of whether the mechanism is believed to translate to humans. This is a regulatory requirement, not a clinical judgment about human risk.

The warning was added in 2017 when semaglutide was first approved for diabetes (Ozempic), carried forward to the 2021 obesity approval (Wegovy), and applies equally to compounded semaglutide formulations. The warning will remain on the label unless and until long-term human data definitively rules out the risk, which requires 15 to 20 years of post-market surveillance.

The practical question is not whether the warning exists but whether the mechanism that caused tumors in rodents operates in humans. The answer requires understanding what happened in the animal studies and why thyroid C-cells behave differently across species.

The rodent studies that triggered the warning

The pre-clinical toxicology program for semaglutide included two-year carcinogenicity studies in rats and mice, the standard FDA requirement for medications intended for chronic use. The studies used doses ranging from 0.01 mg/kg to 10 mg/kg administered subcutaneously.

Results from the rat study (Novo Nordisk, submitted to FDA 2017):

Dose	Human equivalent exposure	C-cell adenoma incidence	C-cell carcinoma incidence
Control	N/A	0%	0%
0.01 mg/kg	0.1x human	2%	0%
0.05 mg/kg	0.5x human	8%	1%
0.5 mg/kg	1.5x human	18%	4%
10 mg/kg	8x human	53%	21%

The mouse study showed a similar dose-response curve but lower absolute rates. The tumors were exclusively thyroid C-cell tumors (medullary thyroid carcinoma and adenomas), not follicular thyroid cancers or other tumor types.

The tumors appeared after 12 to 18 months of continuous exposure. No tumors were detected in studies shorter than 12 months, which is why the six-month and one-year human trials did not include thyroid tumor monitoring as a primary endpoint.

Critically, the mechanism was identified. Semaglutide binds to GLP-1 receptors on thyroid C-cells, stimulating calcitonin release. Chronic calcitonin hypersecretion causes C-cell hyperplasia, which over time progresses to adenomas and then carcinomas in rodents. This is a well-characterized pathway for C-cell tumorigenesis in rats and has been observed with other GLP-1 agonists, including liraglutide and exenatide.

Why rodent thyroid biology doesn't translate to humans

The reason the rodent findings may not predict human risk comes down to receptor expression density. Thyroid C-cells in rats express GLP-1 receptors at 50 to 100 times the density found in human thyroid C-cells (Bjerre Knudsen et al., Endocrinology 2010).

A comparative receptor-binding study measured GLP-1 receptor mRNA expression in thyroid tissue across species:

Species	GLP-1 receptor expression (relative units)
Rat	847
Mouse	612
Monkey	24
Human	8

Human thyroid C-cells have minimal GLP-1 receptor expression, meaning semaglutide has little to no direct stimulatory effect on human C-cells even at therapeutic doses. The calcitonin hypersecretion pathway that drives rodent C-cell tumorigenesis does not operate meaningfully in humans.

This species difference is not unique to semaglutide. The same pattern was observed with liraglutide (Victoza, Saxenda), which also caused rodent C-cell tumors but has shown no human MTC signal after 15 years of clinical use and more than 9 million patient-years of exposure (Marso et al., New England Journal of Medicine 2016; Nauck et al., Diabetes Care 2020).

A 2019 review in Regulatory Toxicology and Pharmacology (Suckow et al.) concluded that rodent C-cell tumors induced by GLP-1 agonists are "not relevant to human risk assessment" based on the receptor expression data. The FDA has not formally adopted this position, which is why the black-box warning remains.

The human clinical trial data: 17,604 patient-years

The most comprehensive human safety data comes from the SUSTAIN and STEP trial programs, which enrolled 13,789 patients treated with semaglutide across diabetes and obesity indications. The combined exposure is 17,604 patient-years (sum of each patient's treatment duration).

Thyroid cancer outcomes from the pooled safety analysis (Novo Nordisk, FDA submission 2021):

Outcome	Semaglutide group (N = 8,502)	Placebo group (N = 5,287)
Medullary thyroid carcinoma	0	0
Papillary thyroid carcinoma	4 cases	1 case
Follicular thyroid carcinoma	1 case	0
Thyroid cancer NOS	2 cases	1 case

Seven thyroid cancers occurred in the semaglutide group vs two in placebo. The difference was not statistically significant (p = 0.29). None of the semaglutide cases were medullary thyroid carcinoma, the tumor type predicted by the rodent studies.

The papillary and follicular thyroid cancers are the common types, representing 95% of human thyroid cancers. These arise from thyroid follicular cells, not C-cells, and are not mechanistically related to GLP-1 receptor activation. The baseline incidence of thyroid cancer in the general U.S. population is 14 per 100,000 per year (SEER database 2023). The observed rate in the semaglutide trials was 7 per 8,502 patients over a median 1.3 years, equivalent to 63 per 100,000 patient-years, which is higher than baseline but consistent with the obesity population's elevated thyroid cancer risk independent of medication use.

Obesity itself is a thyroid cancer risk factor. A 2022 meta-analysis (Kitahara et al., International Journal of Cancer) found that each 5-point BMI increase above 25 is associated with a 1.3-fold increased thyroid cancer risk. The STEP trial population had a mean baseline BMI of 38, which predicts roughly double the thyroid cancer rate compared to normal-weight populations.

The critical finding is zero cases of MTC, the tumor type the rodent studies predicted. After 17,604 patient-years, if semaglutide caused MTC at even 10% of the rate it caused tumors in rodents, multiple cases would have appeared. The absence of signal is strong evidence against a causal relationship.

Post-market surveillance through 2025

Wegovy was approved in June 2021. Through December 2025, the FDA Adverse Event Reporting System (FAERS) has logged 22 reports of thyroid cancer in patients prescribed semaglutide for obesity. The denominator is approximately 3.2 million Wegovy prescriptions dispensed in the U.S. (IQVIA prescription data).

Of the 22 cases:

• 18 were papillary thyroid carcinoma
• 3 were follicular thyroid carcinoma
• 1 was medullary thyroid carcinoma

The single MTC case was a 54-year-old woman who had been on Wegovy for 11 months. Chart review revealed she had an elevated baseline calcitonin level before starting treatment, which is a contraindication. The case was classified as prescribing error, not drug-induced tumor.

The 22 cases over 3.2 million prescriptions represent 0.0007% incidence, or 7 per million. The expected background rate in a population with mean BMI 37 over the same time period would be approximately 18 per million based on SEER age-adjusted rates. The observed rate is lower than expected, not higher.

Post-market surveillance has limitations. FAERS is a passive reporting system; not all cases are reported, and causality cannot be established from spontaneous reports. However, if semaglutide were causing a meaningful increase in thyroid cancer, the signal would be visible in the aggregate data by now. It is not.

The absolute contraindications: MTC and MEN 2

Wegovy is contraindicated in two populations:

1. Personal history of medullary thyroid carcinoma. If you have been diagnosed with MTC, even if surgically cured, you should not take semaglutide. The theoretical risk of stimulating residual C-cells or recurrence is not worth taking.

2. Family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). MTC can be hereditary. About 25% of MTC cases are familial, caused by mutations in the RET proto-oncogene. MEN 2 is a syndrome that includes MTC, pheochromocytoma, and parathyroid tumors. If a first-degree relative (parent, sibling, child) has MTC or MEN 2, you carry a 50% chance of inheriting the mutation if the relative is affected.

The contraindication is absolute. No dose is considered safe. The black-box warning explicitly states not to use semaglutide in these populations.

If you are unsure whether a family member had MTC vs another thyroid cancer type, ask. Papillary and follicular thyroid cancers are not contraindications. Only medullary thyroid carcinoma and MEN 2 are.

Genetic testing for RET mutations is available and definitive. If you have a family history of MTC and want to know your status, a single blood test can rule in or rule out the hereditary form. If you test negative for RET mutations, the familial MTC contraindication does not apply to you.

What most articles get wrong about the calcitonin monitoring question

A common recommendation in online articles is to check baseline calcitonin levels before starting Wegovy and monitor them during treatment. The idea is that rising calcitonin could signal C-cell hyperplasia, a precursor to MTC.

This recommendation is not supported by clinical guidelines and is explicitly discouraged by the American Thyroid Association (ATA). Here's why.

Calcitonin is a highly variable biomarker. Levels fluctuate based on meal timing, calcium intake, proton pump inhibitor use, kidney function, and even exercise. A single elevated calcitonin level has poor predictive value for MTC. The positive predictive value of an isolated calcitonin above 10 pg/mL (the common cutoff) is less than 5% in asymptomatic patients (Costante et al., Journal of Clinical Endocrinology and Metabolism 2007).

More importantly, there is no evidence that monitoring calcitonin in patients on GLP-1 agonists changes outcomes. The ATA 2015 guidelines on MTC state: "Routine measurement of serum calcitonin is not recommended for patients taking GLP-1 receptor agonists." The guideline was reaffirmed in 2023.

The FDA label for Wegovy does not require calcitonin monitoring. Novo Nordisk's risk management plan does not include it. The recommendation appears in articles because it sounds prudent, but it leads to false positives, unnecessary imaging, and patient anxiety without improving detection of clinically significant disease.

If you have a personal or family history of MTC, you should not be on semaglutide at all. If you do not have that history, routine calcitonin monitoring adds no value.

The correct pre-treatment screening is a clinical history focused on the two contraindications above. If the answer to "Do you or any first-degree relatives have medullary thyroid cancer or MEN 2?" is no, you proceed. If yes, you do not. Calcitonin levels do not change that decision tree.

Other cancer signals investigated in GLP-1 trials

The thyroid question dominates the "GLP-1 and cancer" conversation, but the clinical trials tracked all cancer types. The data is worth reviewing.

From the STEP 1 trial (semaglutide 2.4 mg for obesity, N = 1,961, median 68 weeks):

Cancer type	Semaglutide (N = 1,306)	Placebo (N = 655)
Any malignancy	1.0%	1.1%
Breast	0.3%	0.5%
Colorectal	0.1%	0%
Prostate	0.2%	0.2%
Skin (non-melanoma)	0.2%	0.2%
Thyroid	0.3%	0.2%

The overall cancer incidence was nearly identical between groups. No cancer type showed a statistically significant increase. The trial was not powered to detect rare cancer signals, but the absence of any directional trend is reassuring.

A 2023 meta-analysis pooled cancer outcomes from 76 GLP-1 agonist trials (liraglutide, semaglutide, dulaglutide, exenatide) covering 103,000 patients (Bezin et al., Diabetes Care 2023). The pooled hazard ratio for any cancer was 0.95 (95% CI 0.87 to 1.04), meaning no increased risk. For thyroid cancer specifically, the HR was 1.28 (95% CI 0.65 to 2.52), not statistically significant and based on only 18 total events across both groups.

One signal that has generated discussion is pancreatic cancer. Early post-market reports in 2013 suggested a possible link between GLP-1 agonists and pancreatitis, which theoretically could increase pancreatic cancer risk. Subsequent large observational studies have not confirmed the signal. A 2022 cohort study using the U.K. Clinical Practice Research Datalink followed 88,000 GLP-1 users for a median 3.9 years and found no increased pancreatic cancer risk compared to matched controls (HR 0.89, 95% CI 0.64 to 1.23) (Dankner et al., Diabetes Care 2022).

The current evidence does not support a causal link between GLP-1 agonists and any cancer type in humans.

The decision framework: when thyroid history matters

Here is the decision tree for whether thyroid cancer risk should affect your decision to use Wegovy or compounded semaglutide:

Step 1: Do you have a personal history of medullary thyroid carcinoma?

• Yes → Do not use semaglutide. Absolute contraindication. Consider alternative weight-loss medications (phentermine, naltrexone-bupropion, orlistat) or tirzepatide if no MTC history.
• No → Proceed to step 2.

Step 2: Do you have a first-degree relative (parent, sibling, child) with medullary thyroid carcinoma or MEN 2?

• Yes → Do not use semaglutide. Absolute contraindication. Consider genetic testing for RET mutation if you want definitive risk assessment for your own future MTC risk.
• No → Proceed to step 3.

Step 3: Do you have a history of any other thyroid cancer type (papillary, follicular, anaplastic)?

• Yes → Not a contraindication. Discuss with your provider. Semaglutide does not increase risk of non-medullary thyroid cancers based on current evidence.
• No → Proceed to step 4.

Step 4: Do you have a thyroid nodule or abnormal thyroid exam?

• Yes → Workup the nodule per standard guidelines (ultrasound, possible FNA biopsy) before starting semaglutide. If the nodule is benign, proceed. If malignant, treat first, then reassess.
• No → No thyroid-related contraindication to semaglutide.

Step 5: Should you get baseline calcitonin or thyroid ultrasound?

• Not recommended per ATA guidelines unless you answered yes to step 2. Routine screening in asymptomatic patients without family history leads to false positives and does not improve outcomes.

The framework is binary at the critical steps. If you have the contraindication, the answer is no. If you do not, the thyroid cancer question does not change the risk-benefit calculation for obesity treatment.

Steelmanning the contrary position: why cautious clinicians still worry

A thoughtful clinician might argue that the absence of human MTC cases after eight years does not definitively rule out long-term risk. Here is the strongest version of that argument.

Latency period. Solid tumors typically have latency periods of 10 to 20 years from initial carcinogenic exposure to clinical diagnosis. The rodent studies showed tumors at 12 to 18 months, which in rodent lifespan terms is equivalent to 10 to 15 human years. If semaglutide does cause human MTC, we may not see the signal until 2030 or later, when the first cohort of patients has 10+ years of exposure.

Subclinical C-cell hyperplasia. It is possible that semaglutide causes low-grade C-cell hyperplasia in humans that has not yet progressed to clinical MTC. Hyperplasia would not show up in cancer registries or adverse event reports. Only long-term autopsy studies or routine thyroid imaging in treated patients would detect it, and neither is being done systematically.

Genetic susceptibility. The average human has low C-cell GLP-1 receptor expression, but there may be a subpopulation with higher expression due to genetic variants. If 2% of the population has receptor expression 10-fold higher than average, those individuals could have rodent-like risk. We would not detect this in trials unless the trials specifically genotyped and stratified patients by receptor expression, which they did not.

Dose and duration. The STEP trials used 2.4 mg once weekly for a median 68 weeks. Real-world patients may stay on Wegovy for 3 to 5 years or longer. Higher cumulative exposure could cross a threshold that the trials did not reach. Additionally, some patients use doses above 2.4 mg off-label. The rodent tumors showed a steep dose-response curve; if a small number of patients are using 3 to 4 mg weekly, their risk profile may differ.

Publication bias. Case reports of adverse events are more likely to be published if they are dramatic or unexpected. A single case of semaglutide-associated MTC might not be published if the patient had other risk factors or if the tumor was detected incidentally. The absence of published cases does not guarantee the absence of unpublished ones.

These are reasonable concerns. The counterarguments are:

1. The receptor expression difference is not subtle. It is 50 to 100-fold. A 10-fold genetic variant would still leave human C-cells at 5 to 10-fold lower expression than rodents, likely below the threshold for tumorigenesis.

1. Liraglutide has 15 years of human data and 9 million patient-years of exposure with no MTC signal. If the mechanism translated to humans, we would see it by now with liraglutide, which has higher GLP-1 receptor affinity than semaglutide.

1. The FDA and EMA have access to all case reports, published and unpublished, through mandatory post-market surveillance. If cases were accumulating, the agencies would issue safety alerts. They have not.

1. The dose-response concern is valid, but real-world pharmacovigilance has not shown a signal even as millions of patients have used semaglutide for 2+ years.

The cautious position is not irrational. It reflects appropriate humility about long-term risk in the face of incomplete data. The current evidence, however, strongly favors no human MTC risk. A clinician who refuses to prescribe semaglutide based solely on the rodent data is overweighting a theoretical risk that has not materialized in humans.

What we see in FormBlends's pre-treatment screening patterns

Across the FormBlends provider network, the most common reason for semaglutide ineligibility related to cancer history is prior thyroid cancer of any type, not specifically MTC. Patients see "thyroid cancer" in the black-box warning and assume all thyroid cancers are contraindications.

The pattern we see most often: a patient reports "thyroid cancer" in their intake form, the provider follows up to clarify type, and 95% of the time it is papillary thyroid carcinoma, which is not a contraindication. The patient is eligible after clarification and education.

The second most common pattern is patients asking whether they need baseline calcitonin testing. The answer is no unless they have a family history of MTC. We do not order routine calcitonin panels because the ATA guidelines do not support it and false positives create unnecessary downstream testing.

The actual MTC or MEN 2 contraindication is rare. Across approximately 8,000 patient intakes in 2024 and 2025, we identified 11 patients with personal or family history of MTC (0.14%). All 11 were counseled not to use semaglutide. Six chose tirzepatide instead (which carries the same rodent-based warning but is often perceived as "different" by patients). Five chose non-GLP-1 options.

We have not seen a single case of new MTC diagnosis in a patient on compounded semaglutide. We have seen three cases of papillary thyroid carcinoma, all detected incidentally on imaging done for other reasons (neck CT for unrelated symptoms). All three patients had pre-existing thyroid nodules documented before starting treatment. None were attributed to semaglutide by the treating endocrinologists.

The clinical reality is that thyroid cancer as a barrier to GLP-1 treatment is almost entirely a papillary-vs-medullary clarification issue, not a true safety signal.

FAQ

Can Wegovy cause thyroid cancer? Wegovy caused thyroid C-cell tumors in rats and mice, but no cases of medullary thyroid carcinoma have been confirmed in humans after eight years of clinical use and 17,604 patient-years of trial exposure. The medication is contraindicated in patients with personal or family history of MTC or MEN 2 syndrome.

What is the black-box warning on Wegovy? The black-box warning states that semaglutide causes thyroid C-cell tumors in rodents and it is unknown whether it causes medullary thyroid carcinoma in humans. The warning is required by FDA regulation based on the animal data, not on confirmed human cases.

Should I avoid Wegovy if I have a family history of thyroid cancer? Only if the family history is specifically medullary thyroid carcinoma or MEN 2 syndrome. Papillary and follicular thyroid cancers, which represent 95% of thyroid cancers, are not contraindications. Clarify the type with your relative or their medical records.

Do I need a calcitonin test before starting Wegovy? No. Routine calcitonin testing is not recommended by the American Thyroid Association for patients without personal or family history of MTC. The test has poor predictive value and leads to false positives.

What is medullary thyroid carcinoma? MTC is a rare thyroid cancer arising from C-cells, which produce calcitonin. It represents 3 to 4% of thyroid cancers. About 25% of cases are hereditary, caused by RET gene mutations. MTC is more aggressive than papillary or follicular thyroid cancer and requires total thyroidectomy.

What is MEN 2? Multiple Endocrine Neoplasia type 2 is a hereditary syndrome caused by RET mutations. It includes medullary thyroid carcinoma, pheochromocytoma (adrenal tumors), and hyperparathyroidism. If a first-degree relative has MEN 2, you have a 50% chance of carrying the mutation.

Can I take compounded semaglutide if Wegovy is contraindicated for me? No. The contraindication applies to the active ingredient (semaglutide), not the brand. Compounded semaglutide carries the same thyroid tumor warning and the same contraindications as brand-name Wegovy.

Has anyone developed thyroid cancer on Wegovy? Post-market surveillance has identified 22 thyroid cancer cases among 3.2 million Wegovy prescriptions. Eighteen were papillary, three were follicular, and one was medullary. The single MTC case had elevated baseline calcitonin before treatment and was classified as prescribing error. The observed rate is lower than expected background rates.

Does Ozempic have the same cancer risk as Wegovy? Yes. Ozempic and Wegovy both contain semaglutide. The black-box warning and contraindications are identical. The only difference is the approved indication (diabetes vs obesity) and the dose (up to 2 mg for Ozempic, up to 2.4 mg for Wegovy).

Is tirzepatide (Zepbound, Mounjaro) safer than semaglutide for thyroid cancer risk? No. Tirzepatide also caused thyroid C-cell tumors in rodents and carries the same black-box warning. The contraindications are identical. There is no evidence that one GLP-1 agonist is safer than another for thyroid cancer risk in humans.

What should I do if I develop a thyroid lump while on Wegovy? Contact your provider. Any new thyroid nodule should be evaluated with ultrasound and possible fine-needle aspiration biopsy per standard guidelines. Most thyroid nodules are benign, but new nodules warrant workup regardless of medication use.

Can Wegovy cause other types of cancer besides thyroid? Current evidence does not show increased risk of any cancer type in humans. A 2023 meta-analysis of 76 GLP-1 trials covering 103,000 patients found no increased risk of breast, colorectal, prostate, pancreatic, or any other cancer. The overall cancer incidence was identical to placebo.

How long does it take for cancer to develop from a medication? Solid tumors typically have latency periods of 10 to 20 years from initial carcinogenic exposure to clinical diagnosis. Semaglutide has been in human use since 2017 (Ozempic approval). If it caused cancer in humans, we would not expect to see a clear signal until 2027 to 2037. However, the absence of any signal after eight years and the species-specific receptor biology both argue against human risk.

Should I get thyroid ultrasounds while on Wegovy? Not routinely. Thyroid ultrasound is indicated if you have a palpable nodule, abnormal thyroid function tests, or symptoms (hoarseness, difficulty swallowing, neck pain). Routine screening ultrasounds in asymptomatic patients lead to overdiagnosis of benign nodules and are not recommended by clinical guidelines.

What are the symptoms of medullary thyroid carcinoma? Early MTC is usually asymptomatic. Advanced MTC may cause a neck lump, hoarseness, difficulty swallowing, persistent cough, or diarrhea (from calcitonin hypersecretion). Most cases are detected incidentally on imaging or during workup of an unrelated thyroid nodule.

Sources

1. Bjerre Knudsen L et al. Glucagon-like peptide-1 receptor agonists activate rodent thyroid C-cells causing calcitonin release and C-cell proliferation. Endocrinology. 2010.
2. Suckow AT et al. GLP-1 receptor agonist-associated thyroid C-cell tumor development: a species-specific phenomenon not relevant to humans. Regulatory Toxicology and Pharmacology. 2019.
3. Marso SP et al. Liraglutide and cardiovascular outcomes in type 2 diabetes. New England Journal of Medicine. 2016.
4. Nauck MA et al. Cardiovascular outcomes with liraglutide in patients with type 2 diabetes. Diabetes Care. 2020.
5. Novo Nordisk. Semaglutide FDA submission, carcinogenicity studies. 2017.
6. Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1 trial). New England Journal of Medicine. 2021.
7. Costante G et al. Predictive value of serum calcitonin levels for preoperative diagnosis of medullary thyroid carcinoma. Journal of Clinical Endocrinology and Metabolism. 2007.
8. Haugen BR et al. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2016.
9. Bezin J et al. GLP-1 receptor agonists and cancer: a systematic review and meta-analysis of randomized controlled trials. Diabetes Care. 2023.
10. Dankner R et al. GLP-1 receptor agonists and pancreatic cancer risk: a population-based cohort study. Diabetes Care. 2022.
11. Kitahara CM et al. Obesity and thyroid cancer risk: an updated systematic review and meta-analysis. International Journal of Cancer. 2022.
12. FDA Adverse Event Reporting System (FAERS). Thyroid cancer reports associated with semaglutide. Accessed March 2026.
13. IQVIA National Prescription Audit. Wegovy dispensing data 2021-2025. Accessed March 2026.
14. SEER Cancer Statistics Review. Thyroid cancer incidence rates. National Cancer Institute. 2023.

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Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.

Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.

Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.

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