What Are the Causes of Decreased Birth Control Pill Absorption?

Millions of women around the globe use birth control pills as their primary pregnancy prevention method. If used properly, birth control pills have a 92 to 97 percent effectiveness rate; however, there are certain things that can interfere with the absorption of the pill, thereby increasing the chance of an accidental pregnancy. Knowing what can cause your body to have a reduced ability to absorb the pill can help you plan for a back-up birth control method during those times.

Diagnostic Tests and Preparation

According to the McKinley Health Center, the preparation for several diagnostic medical test procedures can interfere with your body’s ability to absorb birth control pills. Whether the doctor prescribed a laxative the night before the procedure or told you to clean your system out, using over-the-counter (OTC) solutions, your body may have a reduced ability to absorb the birth control pill during this process. In addition, the diagnostic test itself may interfere with absorption. It is recommended you use a back-up birth control method for the seven days after the procedure.

Medications

Certain medications, including antibiotics and tuberculosis pills, are thought to interfere with a body’s ability to absorb other medications. This is especially true if you are going to be on the antibiotics or tuberculous medications for longer than 10 days. Herbal supplements, including St. John’s wort, have also been reported to interfere with the absorption of the birth control pill, according to the Aetna InteliHealth website.

Illness

While a head cold will not force you to try a different birth control method, if you get a stomach virus that includes vomiting and diarrhea, you probably need to consider condoms or abstinence until the illness has passed. Diarrhea creates a situation in your body where food and pills pass through too quickly, stripping the ability to absorb either one.