Can I take levothyroxine and metoprolol together? Understanding the timing and safety

October 10, 2025 •

4 min read

Millions of people worldwide manage multiple chronic conditions, often requiring them to take different medications simultaneously. For those asking, 'Can I take levothyroxine and metoprolol together?', the answer is often yes, but with careful timing and medical supervision to prevent drug interactions.

Quick Summary

Taking levothyroxine and metoprolol concurrently is generally safe with proper medical oversight and separated dosing schedules. The key to effective treatment and avoiding interactions lies in precise timing, as levothyroxine must be taken on an empty stomach and separated from other medications, including metoprolol.

Key Points

Separation is Key: Take levothyroxine and metoprolol at different times of the day to ensure proper absorption and effectiveness of both medications.
Optimal Timing: Levothyroxine should be taken on an empty stomach, while metoprolol is best taken with or after food.
4-Hour Rule: A time gap of at least 4 hours is recommended between taking levothyroxine and any other medication or supplement.
Medical Supervision: Close monitoring of heart rate, blood pressure, and thyroid levels by a healthcare provider is essential, especially when starting or adjusting dosages.
Symptom Vigilance: Report any concerning symptoms like a racing heart, anxiety, dizziness, or fatigue to your doctor, as these may indicate a need for dosage adjustments.
Open Communication: Always inform your doctor and pharmacist about all medications, vitamins, and supplements you take to avoid potential interactions.

Understanding Your Medications

Before exploring how these medications can be taken together, it's essential to understand their individual functions. Levothyroxine and metoprolol treat different conditions but can both have a significant impact on the cardiovascular system.

What is Levothyroxine?

Levothyroxine is a synthetic form of the thyroid hormone T4, and it is used to treat hypothyroidism (underactive thyroid). Hypothyroidism occurs when the thyroid gland doesn't produce enough thyroid hormone, leading to a slowed metabolism and various symptoms like fatigue, weight gain, and sensitivity to cold. The medication works by replacing the missing hormone, which can lead to an increased heart rate as the body's metabolism speeds up.

What is Metoprolol?

Metoprolol is a beta-blocker, a class of drugs used to treat conditions like high blood pressure, chest pain (angina), and heart failure. Beta-blockers work by blocking the effects of adrenaline, which in turn slows the heart rate and relaxes blood vessels. This makes it easier for the heart to pump blood, improving blood flow and lowering blood pressure.

The Potential for Interaction

While it is often necessary to take both medications, their differing effects on the heart's function mean careful management is required. The primary concerns revolve around the heart rate and blood pressure, as well as medication absorption and metabolism.

Opposing Cardiovascular Effects: Levothyroxine treatment can increase heart rate, while metoprolol is prescribed to slow it down. If levothyroxine increases the heart rate, it can potentially make the beta-blocking effect of metoprolol less effective. A doctor may need to monitor heart rate and blood pressure more frequently and adjust dosages as needed.
Absorption Interference: Levothyroxine is a very sensitive medication when it comes to absorption. Many substances, including some minerals found in other drugs and supplements, can bind to it and prevent it from being fully absorbed by the body. While metoprolol itself doesn't cause this binding, the critical timing for levothyroxine means it must be taken separately from all other medications to ensure consistent absorption.
Metabolism Impact: In some cases, metoprolol may influence the metabolism of levothyroxine, potentially affecting thyroid hormone levels. It is important for a doctor to monitor a patient's thyroid function and make adjustments if necessary when starting or stopping metoprolol.

The Importance of Correct Timing

Timing is the most critical factor when taking these two medications together. A simple scheduling strategy can prevent potential interactions and ensure both drugs work as intended. The general rule is to separate the doses to avoid any interference.

Here is a step-by-step guide to proper timing:

Take Levothyroxine first thing in the morning: The standard recommendation is to take levothyroxine on an empty stomach, at least 30-60 minutes before eating or drinking anything other than water. Taking it in the morning often fits into a person's routine most easily.
Wait at least 4 hours: To be safe, a time gap of at least 4 hours should be maintained between taking levothyroxine and any other medication or supplement, including metoprolol.
Take Metoprolol with or after a meal: Unlike levothyroxine, the absorption of metoprolol can be enhanced by food. Therefore, taking metoprolol with or immediately following a meal is often recommended to maintain consistent levels in the body.

Managing Co-Administration Safely

If you are prescribed both medications, your healthcare provider will want to monitor your condition closely. Regular monitoring is essential to ensure both treatments are effective and that you are not experiencing any adverse effects.

Here is what you and your doctor will manage:

Regular Blood Tests: Your thyroid-stimulating hormone (TSH) levels should be checked regularly. Consistent timing of your levothyroxine dose is critical to ensure these blood test results are accurate and reflective of your thyroid function.
Cardiovascular Monitoring: Your heart rate and blood pressure should be checked regularly, especially when first starting or adjusting either medication. This ensures metoprolol is effectively controlling heart-related symptoms without causing excessive bradycardia (slow heart rate) or hypotension (low blood pressure).
Symptom Awareness: Pay close attention to any symptoms that might indicate a dosage issue. For instance, if you experience a racing heart, anxiety, or insomnia, your levothyroxine dose might be too high. Dizziness, fatigue, or an unusually slow heart rate might suggest a problem with the metoprolol dose.
Communication with Your Doctor: Always inform your doctor and pharmacist about all the medications and supplements you are taking. This includes over-the-counter drugs, vitamins, and herbal products, which can also interfere with these prescriptions.

Comparison of Levothyroxine and Metoprolol Dosing


Feature	Levothyroxine	Metoprolol
Primary Purpose	Thyroid hormone replacement (Hypothyroidism)	Beta-blocker (High BP, angina, heart failure)
Cardiovascular Effect	Increases heart rate (metabolism boost)	Decreases heart rate (adrenaline blocker)
Best Taken	On an empty stomach, 30-60 min before breakfast or 4 hours after dinner	With food or immediately after a meal
Absorption Consistency	Very sensitive to food and other medications; requires isolation	Absorption may be enhanced by food
Time Gap	Must be separated by at least 4 hours from other medications	No specific time gap required from non-interacting medications, but separate from levothyroxine

Conclusion

Taking levothyroxine and metoprolol together is a common and safe practice when managed correctly under a doctor's supervision. The primary rule is to separate the administration times to avoid any potential interference with levothyroxine absorption. By taking levothyroxine on an empty stomach first thing in the morning and metoprolol later with a meal, patients can ensure both medications work as intended. Always communicate with your healthcare provider about your medication schedule and report any unusual symptoms, as they can help monitor your progress and make any necessary dosage adjustments. Consistent adherence to your prescribed regimen is key to managing your conditions effectively and safely. For more detailed information on drug interactions, always consult your physician or refer to authoritative resources like Healthline's guide on levothyroxine interactions.

Frequently Asked Questions

No, you should not take levothyroxine and metoprolol at the same time. It is crucial to separate the doses by at least 4 hours to prevent interference with levothyroxine's absorption.

The main reason is timing and absorption. Levothyroxine requires an empty stomach for consistent absorption, while metoprolol is often taken with food. Mixing them can reduce the effectiveness of your thyroid medication.

Accidentally taking them too close together is unlikely to cause serious harm, but it may lead to less consistent absorption of levothyroxine. If this happens, take your next doses as scheduled and try to be more consistent going forward. Do not take an extra dose to compensate.

Metoprolol can potentially affect the metabolism of levothyroxine, though this is not a major concern with standard use. Your doctor will monitor your thyroid-stimulating hormone (TSH) levels to ensure your dose remains effective.

For most people, taking levothyroxine first thing in the morning on an empty stomach, 30 to 60 minutes before eating, is recommended. Some people may prefer taking it at night, at least 4 hours after their last meal, for similar absorption benefits.

If you experience a fast or irregular heart rate (palpitations), anxiety, or other new or worsening symptoms, contact your doctor. These symptoms could indicate that your levothyroxine dose is too high or that the balance between your medications needs adjustment.

You can typically take metoprolol with other blood pressure medications, but it is important to follow your doctor's instructions, as sometimes dosing is separated to reduce the risk of low blood pressure.