Which medications can cause false positive pregnancy tests?

A false positive pregnancy test can occur when a pregnancy test incorrectly indicates that someone is pregnant when they are not. This can sometimes be caused by certain medications.

Medications that contain human chorionic gonadotropin (HCG), a hormone normally produced during pregnancy, can cause a false positive pregnancy test. Examples include Pregnyl, Profasi, Ovidrel, and Novarel.

These medications are often used in fertility treatments to stimulate ovulation or to help implant an embryo. Because pregnancy tests work by detecting HCG in the urine, these medications can affect the test results.

In rare cases, medications such as certain antipsychotics (Chlorpromazine, Phenothiazines) and antidepressants can stimulate the pituitary gland to produce small amounts of HCG, which can lead to a false positive test. Promethazine can also give a false positive result.

Some diuretics (water pills) have been reported to cause false positive results in very rare cases. Medications such as carbamazepine and phenytoin, which are used to treat seizures, are also rare but can affect test results.

If you suspect a false positive, it is important to talk to a doctor and possibly have a blood test done to confirm the results.

Source: https://www.drugs.com/medical-answers/medications-false-positive-pregnancy-test-3566577/

Author: Prof. Dr. Dirk Devroey - Latest update: 2024-08-14 - Copyright: Clinifacts 2025