Natural D‑Hist® is a targeted, non‑drowsy supplement designed to support immune balance and respiratory comfort during seasonal transitions. This advanced formula blends flavonoids, enzymes, and antioxidants—such as quercetin, bromelain, stinging nettles leaf, N‑acetyl cysteine, and vitamin C—to help stabilize histamine levels, promote clear nasal and sinus passages, maintain healthy mucus viscosity, and support overall sinus health