Levonorgestrel

Drug Information

Common brand names:

Mirena, Norplant System, Plan B

Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • Folic Acid

    Oral contraceptive use can cause folic acid depletion.

  • Vitamin B1

    A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and zinc levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A. Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Vitamin B3 (Niacin)

    A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and zinc levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A. Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

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

    A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and zinc levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A. Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

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

Reduce Side Effects

  • Folic Acid

    In a double-blind trial of oral contraceptive users with cervical dysplasia, supplementation with very large amounts (10 mg per day) of folic acid improved cervical health. Women with cervical dysplasia diagnosed while they are taking oral contraceptives should consult a doctor. Mega-folate supplementation should not be attempted without a doctor’s supervision, nor is there any reason to believe that folic acid supplementation would help people with cervical cancer.

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • St. John’s Wort

    Eight cases reported to the Medical Products Agency of Sweden suggest that St. John’s wort may interact with oral contraceptives and cause intramenstrual bleeding and/or changes in menstrual bleeding. One reviewer has suggested that St. John’s wort may reduce serum levels of estradiol. It should be noted, however, that only three of the eight Swedish women returned to normal menstrual cycles after stopping St. John’s wort. Women taking oral contraceptives for birth control should consult with their doctor before taking St. John’s wort.

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

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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