Some cough syrups are considered low-risk during pregnancy, but others contain ingredients you should avoid. The safety depends entirely on what’s in the bottle, and many popular brands mix several active ingredients together, making it essential to read the label carefully rather than assuming any cough syrup is fine.
Dextromethorphan: The Safer Cough Suppressant
Dextromethorphan, the cough suppressant labeled “DM” on most over-the-counter products, has the most reassuring safety data for pregnancy. A study of 128 women who took it during the first trimester found no increase in miscarriage, and a larger study of 184 women who used it at any point during pregnancy found no increased chance of stillbirth or low birthweight. It is not expected to increase the chance of birth defects.
That said, researchers haven’t studied whether dextromethorphan affects preterm delivery risk or long-term learning and behavioral development. The evidence is reassuring but not exhaustive. If you have a dry, nagging cough that’s disrupting your sleep or daily life, a single-ingredient dextromethorphan product (like Delsym or a store-brand equivalent) is generally the safest medicated option.
Guaifenesin: Probably Fine, Less Certainty
Guaifenesin is the expectorant found in Mucinex and similar products. It works by thinning mucus in your lungs so you can cough it up more easily. Most available evidence suggests it does not significantly increase the chance of birth defects. A few older studies hinted at a small increased risk of certain defects, but the bulk of research points toward any risk being very low.
Less is known about guaifenesin’s effects on miscarriage, preterm delivery, or low birthweight, since those outcomes haven’t been specifically studied. Many providers consider it acceptable after the first trimester, but some prefer to err on the side of caution during those early weeks when organ development is most active.
Ingredients to Avoid or Limit
Pseudoephedrine and Phenylephrine
Many cough syrups include a decongestant to relieve stuffy noses. Pseudoephedrine, the most common one, has been linked to a small increased risk of specific birth defects, including an opening in the baby’s abdominal wall and underdevelopment of part of the small intestine. The American College of Obstetricians and Gynecologists specifically warns against using pseudoephedrine during the first three months of pregnancy. After the first trimester the risk appears lower, but it’s still worth discussing with your provider before reaching for anything containing a decongestant.
Alcohol in Liquid Formulas
This is one that catches people off guard. Some liquid cough syrups, particularly nighttime formulas, contain significant amounts of alcohol. One common allergy preparation was found to contain 15% alcohol, and adult doses of high-alcohol formulations can produce blood alcohol levels equivalent to drinking one alcoholic beverage. No safe threshold of alcohol exposure during pregnancy has been identified. Always check the inactive ingredients list for “alcohol” or “ethanol,” and consider choosing tablets, capsules, or alcohol-free liquid versions instead.
Combination Products
Products like NyQuil, DayQuil, and Theraflu typically bundle a cough suppressant with a decongestant, a pain reliever, and sometimes an antihistamine or alcohol. The problem is that even if one or two of those ingredients are considered safe, the others might not be. You also risk accidentally doubling up on a pain reliever if you’re already taking one separately. The safest approach is to use single-ingredient products that target only the symptom bothering you most.
Acetaminophen
Acetaminophen (Tylenol) appears in many multi-symptom cough and cold products. It’s generally considered the safest pain reliever and fever reducer during pregnancy, but the maximum recommended dose is 4,000 milligrams per day for adults. If you’re taking a combination cough syrup that contains acetaminophen, track that amount alongside any other acetaminophen you take so you don’t exceed the daily limit.
Non-Drug Alternatives Worth Trying First
Before reaching for any medication, several drug-free approaches can ease a cough without any exposure concerns. Honey mixed into warm water or tea can soothe a sore throat and help thin mucus so your cough is more productive. Some pregnant women avoid honey because of warnings about infant botulism, but that risk applies only to babies under one year of age, not to pregnant adults. Honey is safe for you.
A cool-mist humidifier in your bedroom adds moisture to the air and can reduce nighttime coughing. Since humidifiers use only water, there’s no medication exposure. Just clean the unit regularly to prevent mold and bacteria buildup. Nasal irrigation with a neti pot or squeeze bottle, using previously boiled or distilled water mixed with saline, can clear congestion from your nasal passages. While studies haven’t shown it shortens colds significantly, many people find real relief from it, and it involves no medication at all.
Prescription Cough Medicines
If your cough is severe enough that your provider considers a prescription option, the most commonly discussed one is benzonatate (sometimes sold as Tessalon Perles). The FDA classifies it as Pregnancy Category C, meaning animal reproduction studies haven’t been done and it’s unknown whether it can cause fetal harm. It’s only used when the benefit clearly outweighs the unknown risk, which means it’s typically a last resort rather than a first-line option.
Codeine-containing cough syrups carry their own set of concerns during pregnancy, including the potential for neonatal withdrawal symptoms if used near delivery. These are rarely recommended.
Signs Your Cough Needs Medical Attention
Most coughs during pregnancy are caused by ordinary colds and resolve within one to two weeks. But certain symptoms warrant a call to your provider. A fever of 100.4°F or higher during pregnancy is a red flag that could indicate an infection needing treatment. A cough that produces green or yellow mucus and lasts more than 10 days may suggest a bacterial infection rather than a simple cold. Difficulty breathing, wheezing, or chest tightness goes beyond a normal cough and needs evaluation.
If you notice your baby’s movements slowing down or stopping during an illness, or you develop a headache that won’t respond to rest and fluids, those are urgent maternal warning signs identified by the CDC that call for immediate medical contact. A persistent cough can also trigger severe nausea or abdominal pain, both of which deserve attention on their own during pregnancy.