MAJOR — Use With Caution
DANGEROUS — charcoal dramatically reduces levothyroxine absorption
Evidence level: STRONG
Activated charcoal absorbs your thyroid medication, preventing it from working. This is especially dangerous because thyroid medication dosing is very precise.
Activated charcoal adsorbs levothyroxine in the GI tract, dramatically reducing absorption. Levothyroxine has narrow therapeutic index making any absorption reduction clinically significant.
Take levothyroxine at least 4 hours before or after activated charcoal. Ideally take levothyroxine first thing in morning on empty stomach and charcoal later in day.
Take each with food, spaced 1-2 hours apart when possible. Always inform your healthcare provider about supplement use alongside prescription medications.
Narrow therapeutic index of levothyroxine, patients recently dose-adjusted
Hypothyroid symptoms: fatigue, weight gain, cold intolerance, constipation, brain fog, hair loss
Discuss timing of all supplements relative to levothyroxine. Charcoal use must be disclosed.
Thyroid medications are sensitive to absorption interference. Take levothyroxine on an empty stomach, 30-60 minutes before food or other supplements. Space calcium, iron, and antacids at least 4 hours away. Selenium and zinc are generally safe thyroid-supporting nutrients.
Activated charcoal absorbs your thyroid medication, preventing it from working. This is especially dangerous because thyroid medication dosing is very precise.
Take each with food, spaced 1-2 hours apart when possible. Always inform your healthcare provider about supplement use alongside prescription medications.
Hypothyroid symptoms: fatigue, weight gain, cold intolerance, constipation, brain fog, hair loss
Thyroid medications are sensitive to absorption interference. Take levothyroxine on an empty stomach, 30-60 minutes before food or other supplements. Space calcium, iron, and antacids at least 4 hours away. Selenium and zinc are generally safe thyroid-supporting nutrients.
Discuss timing of all supplements relative to levothyroxine. Charcoal use must be disclosed.
Or browse the full interaction database (121,000+ pairs).