From the manufacturer's website:

The Natural D-Hist formula includes optimal support for nasal and sinus passageways for individuals who anticipate seasonal changes.

• Supports Immune Balance in Hypersensitive Individuals.
• Supports Sinus and Respiratory Health
• Promotes Normal Viscosity of Mucus
• Clears Nasal Passages

Warnings:Formulated to be free of allergens derived from: Gluten, corn, yeast, artificial colors and flavors.

Caution: If you are pregnant or nursing, consult your physician before taking this product. As with all dietary supplements, some individuals may not tolerate or may be allergic to the ingredients used. Please read the ingredient panel carefully prior to ingestion. Cease taking this product and consult your physician if you have negative reactions upon ingestion.

Keep container tightly closed. Store at room temperature. Keep out of reach of children.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.

Serving Size:2 Capsules Servings Per Container: 60

Ingredients (Amount Per Serving):

• Vitamin C (as Ascorbic Acid USP)300 mg
• Quercetin Dihydrate400 mg
• Stinging Nettle (leaves)400 mg
• Bromelain (2,400 GDU/g) (from Pineapple)100 mg
• N-Acetyl-L-Cysteine USP50 mg