YSK that when you take certain antibiotics the effect of your birth control pills may decrease drastically and/or become ineffective.

185 points•16 comments•submitted by -73ss0n to r/YouShouldKnow

"Birth control pills contain estrogens. Some antibiotics, e.g., rifampin, griseofulvin, cause the enzymes in the liver to increase the break-down of estrogens and thereby can decrease the levels of estrogens in the body and the effectiveness of the pills. This can result in unwanted pregnancy."

Source: https://www.medicinenet.com/effects_of_antibiotics_on_birth_control_pills/ask.htm