There are very few medications that are deemed unsafe for use by a nursing mother. Taking Nyquil as directed while breastfeeding is unlikely to cause any harm to your baby, but it is recommended that you take alternative over-the-counter medications that would lower any potential risk even further.
Medications and Breast Milk
Less than 1 percent of any medication will be passed through your breast milk. This small amount of Nyquil is unlikely to have a negative effect on your baby.
Nyquil is a multi-symptom formula, meaning it is used to treat a variety of cold symptoms from coughing to aching muscles. The Cleveland Clinic recommends that if you are only suffering from one symptom to choose a single-ingredient medication. If you are suffering from a stuffy nose for example, choose a nasal decongestant only rather than Nyquil which contains a variety of ingredients.
Always read and follow Nyquil product instructions and pay attention to any precautions related to breastfeeding. Product recommendations change over time so it is important that you always read instructions thoroughly.
To further decrease the risk of Nyquil being passed in breast milk, breastfeed your baby right before taking the medicine or two to four hours after. If your baby is still nursing with greater frequency than every two hours, you will want to consider this before taking Nyquil.
Monitor your baby after having taking Nyquil and breastfeeding to make sure that she is not drowsy, sleepless, or displaying any other unusual behaviors. Drugs that are safe to take during pregnancy are generally safe to take while breastfeeding. If possible, avoid taking Nyquil and choose one of these safer alternatives.