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Drug Information

Methyldopa is a drug used to lower blood pressure in people with hypertension (high blood pressure).

Common brand names:


Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • Vitamin B12

    Methyldopa can decrease vitamin B12 levels, thus increasing the risk of vitamin B12 deficiency.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • Iron

    Iron supplements have been found to decrease methyldopa absorption. Taking methyldopa two hours before or after iron-containing products can help avoid this interaction.

Potential Negative Interaction

  • Excess dietary sodium (salt) intake can cause fluid retention and interfere with the blood pressure lowering action of methyldopa. Reducing the use of table salt and heavily salted foods during methyldopa therapy reduces the likelihood of this interference.

Explanation Required 

  • none

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.

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