What Interferes With the OPK?

    Ovulation prediction kits OPK are sensitive to the luteinizing hormone (LH). While most medications will have no effect on the test results, there are a certain sector of medications that can have a very real effect.

    Ovulation prediction kits are sensitive to the luteinizing hormone (LH). While most medications will have no effect on the test results, there are a certain sector of medications that can have a very real effect. These medications are often prescribed for infertility. If a woman is not producing enough LH she may not be able to conceive. For this reason, some infertility medications contain LH to improve the chances of fertility.

    Infertility Medications and False Positive Ovulation Test Results

    Several infertility medications can cause the ovulation kit to test falsely positive. These may include Clomid, Pergonal, Humegon and Repronex. Clomid is one of the most commonly prescribed infertility medications. Clomid can cause an ovulation prediction kit to test positive when the woman is not ovulating. According to the manufacturer of Clomid, three days should pass between the last day taking the Clomid and the first day testing for ovulation. For instance, if the medication is taken for 10 days, it is okay to start using the ovulation prediction kit on the 14th day.

    Pergonal, Humegon and Repronex are three infertility medications that contain LH and a follicle stimulating hormone (FSH). There could be enough LH in these medications to boost the natural LH levels to a point that looks like a spike. While this spike will not be the true spike noticed immediately before ovulation, the test will not be able to differentiate the difference between the two.

    Other infertility medications like Gonal-F, Follistem and Fertinex contain only the follicle stimulating hormone. These should not have any effect on the ovulation prediction kit as the kit does not test for FSH.

    Before starting to use an ovulation prediction kit, make sure to ask a pharmacist or your prescribing physician whether the medication causes a boost in natural LH or contains LH.