This sheet talks about exposure to guaifenesin in a pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare providers.

What is guaifenesin?

Guaifenesin is an oral medication called an expectorant. Expectorants are used to thin and loosen mucus in the throat and lungs. This process makes it easier to cough up and remove the mucus from the body. Guaifenesin can be found in over-the-counter cough and cold medications.

Can taking guaifenesin make it more difficult for me to become pregnant?

There is no evidence that suggests taking guaifenesin will make it more difficult to become pregnant.

Can taking guaifenesin during my pregnancy cause birth defects?

In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. It is unlikely that guaifenesin would increase this chance. Most studies suggest that guaifenesin is not associated with an increase in birth defects.

Can I take guaifenesin while breastfeeding?

The use of guaifenesin while breastfeeding has not been studied. This means it is unknown if guaifenesin can affect a nursing baby. Breastfeeding mothers should talk to their healthcare provider before taking any medication.

If a man takes guaifenesin, could it affect his fertility (ability to get partner pregnant) or increase the chance of birth defects?

A man’s use of guaifenesin has not been studied for effects on pregnancy. In general, exposures that the father has does not increase risk to a pregnancy. For more information, please see the MotherToBaby fact sheet on Paternal Exposures at

Selected References:

  • Check, J, et al. 1982. Improvement of cervical mucus factor with guaifenesin. Fertility and Sterility, 37(5): 707-708.
  • Dicpinigattis, P. & Gayke, Y. 2003. Effects of guaifenesin on cough reflex and sensitivity. Chest Journal, 126(6): 2178-2181.
  • Heinonen, O.P., et al. 1977. Birth defects and drugs in pregnancy. Littleton, MA: Publishing Sciences Group.
  • Means, G., et al. 2010. Guaifenesin and increased sperm motility: a preliminary case report. Int J Gen Med, 4: 13-14.
  • Shaw, G., et al. 1998. Maternal illness, including fever, and medication use as risk factors for neural tube defects. Teratology, 57: 1-7.
  • Silva, R., Lee, J., & Tweed, E. 2007. Is guaifenesin safe during pregnancy? Family Practice 56 (8): 669-670.
  • Briggs GG, et al. 2017. Drugs in pregnancy and lactation: a reference guide to fetal and neonatal risk. 11th