Supplement stacks / Iron + Levothyroxine
Can You Take Iron with Levothyroxine?
Iron and Levothyroxine: one interaction flagged, scored 6/10 (medium risk). The count and score come from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice.
Safety at a glance
This score comes from an AI-written analysis of the pair. Our interaction rules check it and can only make it stricter, never milder. Informational only: it can't account for your medications, conditions, or genetics.
What the AI-written analysis says
Iron supplements can interfere with the absorption of levothyroxine, potentially reducing its effectiveness. It is generally recommended to separate the intake of these two substances by at least 4 hours to minimize interaction risks. Both iron and levothyroxine have limited evidence quality regarding their interactions, and consulting a healthcare provider is advised for personalized guidance.
Levothyroxine is a prescription medication. This page describes publicly documented interactions — it can't see your dose, your other prescriptions, or your labs. Discuss any supplement with the prescriber or pharmacist who manages this medication before combining.
Known interactions
Suggestion: Take iron and levothyroxine at least 4 hours apart.
Iron
From the AI-written analysis.
Generally safe when taken as directed; excessive intake can lead to toxicity.
Typical dosage: 18-45 mg daily, depending on individual needs.
- Constipation
- Nausea
- Stomach upset
- Monitor for gastrointestinal side effects; consult healthcare provider if experiencing severe symptoms.
Levothyroxine
From the AI-written analysis.
Safe when taken as prescribed; requires regular monitoring of thyroid levels.
Typical dosage: As prescribed or as directed on the label
- Increased heart rate
- Nervousness
- Weight loss
- Regularly monitor thyroid hormone levels; adjust dosage as needed.
Timing
Take as prescribed — we do not schedule prescription medications. Follow the label or your prescriber, and ask your pharmacist before changing when you take it.
Recommendations
- Consult with a healthcare provider before starting iron supplements.
- Consider timing of iron and levothyroxine to avoid absorption issues.
Watch out for
- Calcium, iron, magnesium, chromium, fibre supplements and antacids can lower how much thyroid medication (levothyroxine) is absorbed, which can leave your thyroid under-treated. Keep at least 4 hours between them. Prescribing information has levothyroxine taken on an empty stomach, typically 30-60 minutes before breakfast, so the mineral, fibre supplement, antacid or multivitamin is the one that fits later in the day; follow your prescriber or pharmacist on the levothyroxine itself. Ask for a TSH recheck if you start or change the mineral, the fibre supplement or the antacid.
- Take iron and levothyroxine at least 4 hours apart to avoid absorption interference.
Frequently asked questions
Can you take Iron and Levothyroxine together?
Iron and Levothyroxine: one interaction flagged, scored 6/10 (medium risk). The count and score come from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice.
What score does the Iron and Levothyroxine combination get?
The Iron and Levothyroxine combination is scored 6/10 (medium risk). The score comes from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice. Always confirm with a healthcare professional.
When should you take Iron and Levothyroxine?
Take as prescribed — we do not schedule prescription medications. Follow the label or your prescriber, and ask your pharmacist before changing when you take it.
What should you watch out for when combining Iron and Levothyroxine?
Calcium, iron, magnesium, chromium, fibre supplements and antacids can lower how much thyroid medication (levothyroxine) is absorbed, which can leave your thyroid under-treated. Keep at least 4 hours between them. Prescribing information has levothyroxine taken on an empty stomach, typically 30-60 minutes before breakfast, so the mineral, fibre supplement, antacid or multivitamin is the one that fits later in the day; follow your prescriber or pharmacist on the levothyroxine itself. Ask for a TSH recheck if you start or change the mineral, the fibre supplement or the antacid. Take iron and levothyroxine at least 4 hours apart to avoid absorption interference.
Check your full stack
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Not medical advice
AI-written analysis generated August 10, 2026, checked by our interaction rules · How our analysis works