What is the shelf life of your Bronchial Support herbal syrup? Mig Windows May 11, 2021 19:45 Updated Bronchial Support herbal syrup has a shelf life of five years. We suggest storing it in a cool, dark place—away from heat, humidity, and sunlight—for best results. Related articles Did Beauty Balm win an award? How many servings are in the ½-pound and 1-pound bags of powder? Comments 0 comments Article is closed for comments.