Citric Acid, Diphenhydramine, Ammonium Chloride, Menthol

Citric Acid, a weak organic acid, is commonly used as a flavoring agent in foods and beverages. However, it also has a therapeutic use in this combination medication. When taken orally, it aids in the relief of mild gastrointestinal discomfort by raising the pH level in the stomach, which helps neutralize acidity.
Diphenhydramine, an antihistamine, works by blocking histamine receptors in the body. This action is beneficial in reducing allergy symptoms such as sneezing, itching, and runny nose. Additionally, it has sedative effects, which help induce drowsiness and provide relief from insomnia or sleeplessness.
Ammonium Chloride is a mild respiratory irritant that stimulates the respiratory system by causing an increase in the production of bronchial secretions. This helps to break up and expel mucus in the respiratory tract, providing relief for symptoms of bronchitis, chest congestion, and other respiratory ailments.
Menthol, a cooling agent derived from mint oils, is often used to soothe and relax the muscles in the respiratory and gastrointestinal tracts. Its cooling sensation provides temporary relief from minor throat and stomach irritations.