Based on FDA | Can eating broccoli while taking doxycycline interfere with its absorption or effectiveness?

Eating broccoli with doxycycline is not expected to meaningfully reduce the antibiotic’s absorption or effectiveness for most users. Doxycycline’s absorption is generally robust and is only clearly reduced by certain minerals (like calcium, iron, magnesium, and aluminum) found in supplements, antacids, and some fortified foods, whereas broccoli itself does not contain these minerals at levels known to cause a clinically relevant interaction. In official prescribing information, doxycycline is described as having absorption that is not markedly influenced by simultaneous ingestion of food or milk, unlike older tetracyclines. ^[1] These same materials emphasize that clinically important reductions occur with antacids containing aluminum, calcium, or magnesium, with iron products, and with bismuth subsalicylate. ^[1]

Key point

• Broccoli alone is unlikely to interfere with doxycycline. ^[1]
• Avoid taking doxycycline at the same time as iron, calcium, magnesium, aluminum, or bismuth products (including many antacids), because these can bind the antibiotic and reduce absorption. ^[1]
• If your stomach is sensitive, taking doxycycline with food or milk is acceptable because its absorption is not markedly affected by food. ^[2]

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Why broccoli is different from mineral binders

Doxycycline can bind to “divalent and trivalent cations” (such as calcium, iron, magnesium, and aluminum), forming complexes that the gut absorbs poorly. This effect is well-established for tetracyclines as a class and can reduce absorption significantly when taken together with these minerals. ^[3] However, doxycycline is the exception within the class in that food in general unlike mineral supplements does not markedly diminish its absorption. ^[1] Therefore, vegetables like broccoli are not considered a meaningful risk to doxycycline absorption in typical portions. ^[1]

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Practical timing advice

• OK with meals: You can take doxycycline with meals if you experience stomach upset, as overall absorption is not markedly influenced by food or milk. ^[2] This flexibility helps reduce nausea and the risk of esophageal irritation. ^[2]
• Separate from mineral products: Keep at least a 2–3 hour gap (before or after) between doxycycline and:
  • Calcium or magnesium supplements and calcium/magnesium-containing antacids. These can reduce absorption. ^[1]
  • Iron supplements and multivitamins containing iron. These can reduce absorption. ^[1]
  • Bismuth subsalicylate (commonly in some stomach/diarrhea remedies). This can reduce absorption. ^[1]

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What to watch for

• Gastrointestinal comfort: If doxycycline irritates your stomach, taking it with food (including meals that contain broccoli) is reasonable because absorption remains adequate for most users. ^[2] Drink plenty of water and avoid lying down immediately after taking it to lower the risk of esophageal irritation. ^[2]
• Diet patterns with minerals: If your meal includes high-calcium foods (for example, large servings of dairy) or iron-fortified products at the same time as the dose, the overall impact on doxycycline is still described as not marked, but spacing the antibiotic from heavy mineral loads may be a cautious approach, especially if efficacy is critical. ^[1] The strongest caution remains with supplements and antacids, which deliver concentrated minerals that more reliably interfere. ^[1]

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Summary table

• Food (general, including broccoli): Not markedly affects doxycycline absorption. ^[1]
• Milk/dairy: Not markedly affects doxycycline absorption, can be used to ease stomach upset. ^{[1] [2]}
• Antacids with aluminum, calcium, or magnesium: Reduces absorption; separate by 2–3 hours. ^[1]
• Iron supplements/multivitamins with iron: Reduces absorption; separate by 2–3 hours. ^[1]
• Bismuth subsalicylate: Reduces absorption; separate by 2–3 hours. ^[1]
• Class effect context (tetracyclines + minerals): Chelation can markedly reduce absorption for the class; timing separation prevents it. ^[3]

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Bottom line

Broccoli does not pose a known, clinically significant interaction with doxycycline. Focus instead on avoiding same-time intake of mineral supplements and antacids that contain calcium, magnesium, aluminum, iron, or bismuth, as these can meaningfully reduce absorption. ^[1] If you need to take doxycycline with food for comfort, that is generally acceptable because its absorption is not markedly influenced by food or milk. ^[2]