Quercetin — 250 mg Quercetin is a naturally occurring flavonol widely distributed in plant foods and one of the most extensively studied botanical compounds for histamine regulation and immune balance, functioning as a potent inhibitor of histidine decarboxylase — the enzyme catalyzing the conversion of histidine to histamine — and as a mast cell membrane stabilizer that reduces IgE-triggered degranulation and the release of histamine, leukotrienes, and prostaglandins from sensitized immune cells. Its anti-allergic mechanism operates upstream of symptomatic histamine release, providing prophylactic mast cell stabilization that complements the downstream histamine-catabolizing activity of Vitamin C (as a DAO cofactor) within this formula. At 250 mg per tablet, Quercetin provides a clinically meaningful dose to support healthy histamine levels within normal ranges, nasal mucosal comfort, eye comfort, and healthy skin reactivity during environmental and seasonal allergen challenges.
Bromelain — 250 mg Bromelain is a proteolytic enzyme complex derived from pineapple (Ananas comosus) stem, serving two distinct clinical functions within this formula: first, as an absorption enhancer for quercetin — increasing its gastrointestinal permeability and systemic bioavailability through proteolytic modification of mucosal barrier proteins; and second, as a direct mucolytic and anti-inflammatory enzyme that supports sinus and nasal passage comfort by degrading mucus glycoprotein disulfide bonds to reduce viscosity, and modulating NF-κB-driven inflammatory cytokine production in respiratory tissue. Its proteolytic activity on fibrin and inflammatory protein complexes supports the reduction of mucosal edema and tissue congestion associated with allergic responses, making Bromelain both a bioavailability amplifier for the formula's other active ingredients and a clinically active respiratory and sinus support ingredient in its own right.
N-Acetyl Cysteine (NAC) — 200 mg N-Acetyl Cysteine is the most bioavailable oral precursor to L-cysteine — the rate-limiting amino acid for intracellular glutathione biosynthesis — directly replenishing glutathione stores in respiratory epithelium, nasal mucosa, and immune cells where oxidative burden from allergen-triggered inflammatory cascades is highest. Beyond glutathione precursor activity, NAC exerts direct mucolytic effects by cleaving disulfide bonds within mucus glycoprotein networks — reducing mucus viscosity and improving mucociliary clearance in the bronchial and sinonasal passages — providing therapeutic benefit for the excess mucus production and congestion associated with allergic airway responses. NAC additionally modulates NF-κB activation and cytokine signaling through its glutathione-replenishing and direct thiol-based antioxidant activity, supporting a more balanced and less hyperreactive immune response to environmental triggers.
Perilla (Perilla frutescens) Seed Extract — 75 mg (yielding Rosmarinic Acid 1.13 mg, Luteolin 75 mcg) Perilla seed extract is a traditional Asian botanical standardized to three complementary antiallergic bioactive constituents — polyphenols, rosmarinic acid, and luteolin — each contributing to histamine regulation through distinct molecular mechanisms. Rosmarinic acid, the primary caffeic acid ester in Perilla, inhibits the complement cascade and suppresses IgE-mediated mast cell activation, reducing the initial allergic trigger that drives histamine release from sensitized tissue. Luteolin, a flavone with potent mast cell-stabilizing activity, inhibits the release of both histamine and pro-inflammatory cytokines including IL-4, IL-5, and IL-13 from activated mast cells and basophils. Together, these standardized Perilla constituents provide multitargeted upstream inhibition of the allergic cascade — keeping the nose, eyes, and skin comfortable and preventing the overproduction of phlegm and mucus that characterizes acute allergic responses.
Grape Seed Extract — 150 mg (yielding 142.5 mg Proanthocyanidins) Grape Seed Extract is standardized to 95% oligomeric proanthocyanidins (OPCs) — among the most potent naturally occurring antioxidant compounds available — providing both direct free radical scavenging activity and structural reinforcement of capillary and mucosal vascular walls through their ability to cross-link collagen fibers and stabilize the connective tissue matrix of nasal, sinus, and skin microvasculature. Proanthocyanidins inhibit the enzyme hyaluronidase — which degrades hyaluronic acid in connective tissue during inflammatory events — and support capillary integrity by reducing vascular permeability and the fluid extravasation that contributes to nasal congestion, eye swelling, and skin reactivity during allergic responses. The inclusion of 142.5 mg standardized proanthocyanidins per tablet provides a clinically meaningful dose to support vascular and mucosal tissue structural resilience alongside the histamine-modulating activity of the formula's other ingredients.
