Who should NOT take tirzepatide

Absolute contraindications and cautions

Quick read · 7 min

Last reviewed: April 2026Every claim linked to source

Do not take tirzepatide if you have a personal or family history of medullary thyroid cancer (MTC), Multiple Endocrine Neoplasia type 2 (MEN 2), or are pregnant. Use caution if you have diabetic eye disease, a history of pancreatitis, or severe kidney disease.

In simple terms:
  • Absolute "do not take": MTC history, MEN 2, pregnancy, severe pancreatitis history
  • Use with caution: Diabetic retinopathy, gallbladder disease, severe kidney disease, severe GI problems
  • Tirzepatide can lower blood pressure — your blood pressure medications may need adjustment
  • Insulin & sulfonylureas: increased low blood sugar risk — your doses need adjustment
  • Tell your doctor: thyroid history, allergies, other medications, eating disorders

Based on clinical trials · No rankings · Every claim linked to source


FDA Black Box Warning — Thyroid Tumours

Semaglutide and tirzepatide can cause thyroid C-cell tumours in rodents. This has not been observed in humans, but the FDA requires this warning.

Who is at risk: People with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia type 2 (MEN 2). If this is you, do not take this medication.


Do NOT take if you have:

These are absolute contraindications. Talk to your doctor before starting if any apply to you.

Personal or family history of medullary thyroid carcinoma (MTC)
Do not take

MTC is a rare thyroid cancer. Tirzepatide carries an FDA black box warning for thyroid C-cell tumours (shown in animals, not confirmed in humans). If you have personal history, do not take this drug. If multiple relatives had MTC, get genetic testing for MEN 2 first.

Multiple Endocrine Neoplasia type 2 (MEN 2)
Do not take

MEN 2 is a genetic syndrome that increases thyroid cancer risk. If you have MEN 2, tirzepatide is contraindicated. Ask your doctor about genetic testing if you have a strong family history of thyroid cancer.

Pregnancy or planning pregnancy
Do not take

Tirzepatide causes birth defects in animal studies. Stop at least 2 months before trying to conceive. If you become pregnant while taking it, stop immediately and contact your doctor.

Severe personal history of pancreatitis
Do not take

If you have had acute pancreatitis, tirzepatide carries a risk of triggering it again. Talk to your doctor — the risk-benefit may not favour this drug.

Severe allergy to tirzepatide or any ingredient
Do not take

If you have had anaphylaxis, swelling of the throat, or severe rash from tirzepatide or any GLP-1/GIP drug, do not take it. Tell your doctor immediately.


Pregnancy and breastfeeding

Before pregnancy: Stop semaglutide at least 2 months before trying to conceive. It causes birth defects in animal studies (skeletal malformations, developmental delays).
During pregnancy: Do not take semaglutide. If you become pregnant, stop immediately and contact your doctor.
Breastfeeding: Do not breastfeed while taking semaglutide. It is unknown if it passes into breast milk.

Talk to your doctor about weight loss options if you are planning pregnancy or breastfeeding. Other approaches may be safer.


Talk to your doctor if you have:

These are not automatic contraindications, but require a conversation with your doctor before starting.

Diabetic retinopathy (eye damage from diabetes)
Use with caution

Tirzepatide can worsen existing diabetic retinopathy, especially if blood sugar drops quickly. Most relevant if you have type 2 diabetes with existing eye damage. Your doctor will monitor your eyes. This is not an absolute contraindication — just needs careful monitoring.

Gallbladder disease or history of gallstones
Use with caution

Rapid weight loss increases gallstone formation risk. If you have a history of gallstones, your doctor may monitor with ultrasounds. Not an absolute contraindication, but requires discussion.

Severe gastrointestinal disease (like Crohn's or ulcerative colitis)
Use with caution

Tirzepatide slows stomach emptying, which could worsen severe GI conditions. Mild GI issues (like IBS) are usually fine. Talk to your doctor about your specific condition.

Severe kidney disease (eGFR <30)
Use with caution

Limited data on tirzepatide in severe kidney disease. Your doctor may recommend caution or dose adjustment. Mild to moderate kidney disease is usually okay with monitoring.

Thyroid nodules or abnormal thyroid ultrasound
Use with caution

A baseline thyroid ultrasound may be recommended before starting. Thyroid monitoring during treatment is reasonable. Not an absolute contraindication, but requires discussion.


Quick eligibility summary

Likely a good fit if:

  • BMI 30+ (or 27+ with obesity-related conditions)
  • No personal or family history of MTC / MEN 2
  • Not pregnant or planning pregnancy within 2 months
  • Willing to inject once weekly
  • No severe kidney, liver, or pancreatic disease

Talk to your doctor if:

  • You have a family history of thyroid cancer
  • You have diabetic eye disease or retinopathy
  • You have a history of gallstones
  • You take insulin or diabetes medications
  • You have high blood pressure that is controlled with medication

Not for you if:

  • Personal or family history of MTC
  • Known MEN 2 syndrome
  • Currently pregnant or planning pregnancy soon
  • Severe pancreas or kidney disease
  • Severe allergy to tirzepatide or GLP-1/GIP drugs

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Based on clinical trials · No rankings · Every claim linked to source

Last reviewed: March 2026

Medical disclaimer: This website is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any treatment.