Because supplements may have side effects or interact with medications, they should be taken only under the supervision of a knowledgeable healthcare provider.
Bromelain supplements may help suppress your cough, reduce nasal mucus associated with sinusitis, and relieve swelling and inflammation caused by hay fever. This supplement is often administered with quercetin.
One preliminary study suggested that iron supplementation may soothe and even prevent cough associated with a class of medications known as angiotensin-converting enzyme (ACE) inhibitors (such as enalapril, captopril, and lisinopril). ACE inhibitors are medications commonly used to treat high blood pressure and heart failure, but dry cough is a side effect that leads many people to discontinue their use. Despite this encouraging information, it is premature to conclude that taking iron with ACE inhibitors to reduce dry cough is safe or effective.
Plus, it is important to note that taking ACE inhibitors at the same time as iron may diminish the absorption of this nutrient. Therefore, if used together, the two should be taken at least two hours apart. Also, iron is associated with some risk for heart disease. For this reason, it should not be used if you have high blood pressure, heart disease, or heart failure without the consent and supervision of your physician.
Often, bromelain is used together with quercetin, a flavonoid (plant pigment responsible for the colors found in fruits and vegetables). Quercetin has anti-histamine properties and, therefore, may be helpful if your cough is related to allergies.
Several important studies have revealed that zinc lozenges may reduce the intensity of the symptoms associated with a cold, particularly cough, and the length of time that a cold lingers. Similarly, nasal zinc gel seems to shorten the duration of a cold. However, zinc nasal spray does not appear to have the same benefit.