The pill - do antibiotics render it ineffective?
Does the antibiotic taken before a visit to the dentist render the contraceptive pill ineffective?
Antibiotics do not render the pill ineffective. Broad-spectrum antibiotics, such as are used in dentistry, can reduce the amount of oestrogen that is absorbed from the gut therefore there is less oestrogen absorbed into the body. This reduces the level of contraceptive protection. The reduction is small but it is probably best to take additional contraceptive precautions for seven days after the course of antibiotics. This rule does not apply to the mini pill, which does not contain oestrogen. The risk of becoming pregnant when taking antibiotics while on the pill is extremely low but the conventional wisdom is itís probably better not to run that additional slight risk.