While the active ingredient in Mucinex, guaifenesin, may be safe in the second and third trimesters, we don’t know enough about how this medication might affect an unborn baby. To limit risk, avoid Mucinex throughout pregnancy and reach for an alternative to relieve cough and cold symptoms.

What Is Mucinex?

Mucinex is an over-the-counter cough medicine. Its main ingredient, guaifenesin, works by thinning out mucus, making it easier to clear from the nasal passages, throat, and lungs. “It loosens and thins mucus in the lungs, enabling coughing up the mucus and helping to clear airways, [which makes] breathing easier,” says Alan Lindemann, MD, an obstetrician and maternal mortality expert. Mucinex isn’t for dry coughs. “Mucinex is used for a cough that is productive of mucus, not a dry cough,” says Megan Gray, MD, an ob/gyn with Orlando Health Physician Associates. Some types of Mucinex also include dextromethorphan, a cough medicine that suppresses your brain’s cough reflex. Others may include acetaminophen (Tylenol) for pain relief, or pseudoephedrine, which is a nasal and sinus decongestant. While dextromethorphan and acetaminophen are generally considered safe during pregnancy, pseudoephedrine is not. Mucinex also comes in various formulations and dosages, but it’s best to avoid all of these during pregnancy. In addition, use caution when using any cold medicine with multiple ingredients (such as dextromethorphan and acetaminophen), especially alongside other medicines or over-the-counter products, so that you don’t accidentally consume too much.

Is It Safe to Take Mucinex During Pregnancy?

Not enough research has been done to determine whether Mucinex is safe to take while pregnant. Some studies indicate that Mucinex may be dangerous to take during the first trimester. Since we don’t know enough about how Mucinex might affect a developing fetus during the latter two trimesters, abstaining from this medicine is the safest choice. “It is not yet known if Mucinex is safe to use in pregnancy,” says Dr. Lindemann. “Therefore, I recommend not using it, especially during the first trimester. In any case, ask your doctor or midwife before taking any form of Mucinex.” Mucinex is considered a category C pregnancy drug by the Federal Drug Administration (FDA), which means that it should be avoided due to insufficient research studies. In rare cases, your health care provider may decide that the benefits of Mucinex outweigh the risks of taking it during pregnancy, and allow you to take it during the second and third trimesters.

What If I Take Mucinex Before Realizing I’m Pregnant?

Try not to worry if you took Mucinex before you realized you were pregnant. You didn’t know you were pregnant, so it’s not your fault. Just stop taking it and inform a healthcare provider, advises Dr. Lindemann. If you took Mucinex before missing a period, it’s unlikely that it had any effect at all on your unborn baby. The umbilical cord, which transports substances you ingest to your baby, doesn’t begin to form until five weeks gestation, and you are about four weeks along around the time of your missed period.

Risks of Mucinex While Pregnant

There are not enough research studies done on Mucinex during pregnancy to say for sure what the risks are. This lack of information means there may be risks that no one knows about yet. Some studies have found a possible link between Mucinex in the first trimester and birth defects, but the research is not considered comprehensive enough to say for sure whether Mucinex causes birth defects.

Can I Take Mucinex While Breastfeeding?

It is safe to start taking Mucinex again after you give birth. Once the umbilical cord is cut, you are no longer sharing a bloodline with your baby. If you are breastfeeding, however, you may want to continue to hold off on taking Mucinex until after your baby is weaned or is getting most of their nutrition from other sources. Just as with pregnancy, there is limited data on the use of Mucinex in breastfeeding. Talk with a healthcare provider about whether you can take this medicine or whether you should stick to safer alternatives. “In general, this medication should be used only if necessary and for the shortest duration and lowest dose necessary to manage symptoms,” explains Dr. Gray.

Pregnancy-Safe Alternatives

If you suffer from a productive cough while you are pregnant, it is best to leave the Mucinex on the shelf. However, there are a few safe ways to combat coughs when you have a baby on the way.

Dextromethorphan

Dextromethorphan is an over-the-counter cough medicine that is generally considered safe to use during pregnancy. “This medication suppresses a cough by affecting signals in the brain that trigger a cough,” says Dr. Gray.

Honey

Honey is an effective cough suppressant; it is even more effective than dextromethorphan. Eat it by the spoonful, spread it on toast, or mix it up into warm water or tea to find relief.

Warm Water

Mucinex works by thinning mucus so it becomes easier to clear it from the nasal passages. Warm water has a similar effect. And staying hydrated is also beneficial and important when you are pregnant. When trying to find relief from a cough using warm water, drink it frequently until your cough is completely gone. To maximize effectiveness, take dextromethorphan or honey along with drinking lots of warm or hot water.

A Word From Verywell

Mucinex is not considered safe to take while pregnant because not enough research has been done on how it could affect a developing fetus. Minimal research indicates that taking Mucinex in the first trimester of pregnancy might be linked to birth defects. Avoid taking Mucinex in the first trimester. In the majority of cases, Mucinex should be avoided throughout the entire pregnancy. In some cases, the benefits may outweigh the risks. Always consult a healthcare provider if you have any questions about taking Mucinex while pregnant.