is a comprehensive respiratory support and immune antioxidant formula combining Quercefit (Quercetin Phospholipid Phytosome), Vitamin C, Nettle Extract, and N-Acetyl-L-Cysteine (NAC) in a two-capsule daily serving, featuring the patented Quercefit technology that delivers 20 times greater quercetin bioavailability than standard quercetin supplements, designed to support respiratory health, healthy nasal passages, mast cell stability and histamine balance, antioxidant defense, mucosal immune protection, and resilient immune response throughout the year and especially during seasonal environmental challenges.

Quercetin is the most clinically researched flavonoid for immune and respiratory applications. It is one of the most abundant polyphenols in the food supply, present in onions, apples, berries, and tea, and it has been extensively studied for its ability to stabilize mast cells and prevent histamine release, inhibit pro-inflammatory enzymes including COX-1, COX-2, and lipoxygenase, modulate the NF-kB inflammatory transcription factor, inhibit histamine-1 receptors, and provide potent antioxidant protection in mucosal tissue. The challenge with standard quercetin supplementation is bioavailability: quercetin is a lipophilic flavonoid with relatively poor intestinal absorption, and studies consistently show that a significant fraction of an oral quercetin dose is excreted without being absorbed.

Quercefit is the patented quercetin phytosome developed by Indena S.p.A. in Italy, combining quercetin with phospholipid technology (sunflower lecithin phosphatidylcholine) to create a lipid-compatible complex that absorbs through the intestinal wall with dramatically enhanced efficiency. Human clinical research has demonstrated up to 20 times greater bioavailability for Quercefit compared to standard quercetin aglycone preparations, making 250 mg of Quercefit meaningfully more therapeutically potent than 250 mg of standard quercetin.

The three supporting ingredients address complementary dimensions of the respiratory and immune challenge. Vitamin C at 200 mg (222% DV) provides the primary antioxidant protection in aqueous mucosal environments, supports collagen synthesis in respiratory tissue, and replenishes antioxidant reserves that are rapidly depleted during immune activation. Nettle Extract (Urtica dioica and/or Urtica urens) provides a traditional botanical respiratory support ingredient with in vitro documentation for inhibition of histamine-1 receptors, mast cell tryptase, prostaglandin D2, COX-1, and COX-2, making it the most directly complementary botanical to quercetin's mast cell-stabilizing mechanism. N-Acetyl-L-Cysteine (NAC) at 100 mg serves as the precursor to glutathione, the most important intracellular antioxidant for mucosal immune defense, and functions as a mucolytic agent by hydrolyzing disulfide bonds in mucus proteins, reducing mucus viscosity and facilitating clearance.

Available in 60-capsule (30-serving) and 120-capsule (60-serving) sizes. Formerly evolved from XYMOGEN's AllerDHQ formula with the addition of Quercefit for enhanced quercetin absorption. Vegan, free from gluten, dairy, soy, GMOs, and common allergens. NSF GMP-certified XYMOGEN professional formula.

Key Benefits:

• Quercefit provides 20 times greater quercetin bioavailability than standard quercetin supplements
• Supports mast cell stability and healthy histamine balance
• Supports healthy nasal comfort and respiratory ease
• Supports a healthy inflammatory response via quercetin NF-kB and COX enzyme modulation
• Inhibits histamine-1 receptors, tryptase, prostaglandin D2, and COX-1/COX-2 via nettle extract
• Provides potent antioxidant defense in mucosal and systemic tissue via quercetin, Vitamin C, and NAC
• Supports glutathione synthesis and mucosal immune defense via NAC
• NAC provides mucolytic activity to reduce mucus viscosity and support clearance
• Vitamin C 222% DV supports immune cell function and antioxidant reserve replenishment
• Supports immune readiness and resilience during seasonal environmental challenges
• Supports respiratory tissue integrity and mucosal barrier function
• Vegan, free from gluten, dairy, soy, GMOs, and common allergens
• NSF GMP-certified XYMOGEN professional formula

What's Inside — Full Supplement Facts (per 2-capsule serving):

Vitamin C (as Ascorbic Acid) — 200 mg (222% DV) — The primary water-soluble antioxidant and immune cofactor. Vitamin C is rapidly depleted in mucosal tissue during immune activation and environmental challenge. At 200 mg (222% DV), this provides meaningful antioxidant and immune-supporting activity that complements quercetin's lipophilic antioxidant protection with coverage in aqueous biological compartments. Also supports collagen synthesis in respiratory mucosal tissue and enhances quercetin's absorption through complementary cellular uptake mechanisms.

Quercetin Phospholipid (Quercefit) — 250 mg — Quercefit is a patented quercetin phytosome produced by Indena S.p.A., Italy, where quercetin is complexed with phosphatidylcholine from sunflower lecithin to form a lipid-compatible phytosome structure. Human clinical research demonstrates up to 20 times greater plasma quercetin concentrations from Quercefit compared to an equivalent dose of standard quercetin aglycone, making the 250 mg dose in this formula clinically equivalent to several grams of standard quercetin in terms of systemic availability. In mucosal tissue, quercetin at therapeutic concentrations stabilizes mast cells by inhibiting IgE-mediated degranulation and histamine release, inhibits multiple inflammatory enzyme pathways (COX-1, COX-2, 5-lipoxygenase), and modulates NF-kB nuclear factor activity to reduce inflammatory gene expression in respiratory tissue. Quercefit is a registered trademark of Indena S.p.A., Italy.

Nettle Extract (Urtica dioica and/or Urtica urens, leaves) — 200 mg — Stinging nettle has been used as a natural respiratory and immune remedy for over 2,000 years. Modern in vitro research has identified specific molecular mechanisms behind nettle's traditional use, including inhibition of histamine-1 receptors, inhibition of mast cell tryptase (an enzyme that triggers mast cell degranulation), suppression of prostaglandin D2 production, and inhibition of both COX-1 and COX-2 inflammatory enzyme activity. These mechanisms are directly complementary to quercetin's mast cell-stabilizing activity, providing parallel inhibition at different points in the histamine and inflammatory mediator cascade. Nettle leaves provide flavonoids, phenolic compounds, organic acids, vitamins, and volatile compounds that collectively contribute to its respiratory and immune-supporting activity.

N-Acetyl-L-Cysteine (NAC) — 100 mg — NAC is the acetylated form of L-cysteine, the rate-limiting precursor amino acid for glutathione synthesis. Glutathione is the primary intracellular antioxidant and detoxification cofactor in mucosal tissue, and its depletion during immune and environmental challenge significantly impairs mucosal immune function. NAC replenishes cysteine availability for glutathione synthesis, restoring mucosal antioxidant capacity. Additionally, NAC is a mucolytic agent that disrupts the disulfide cross-links between mucus glycoproteins, reducing the viscosity of nasal and respiratory mucus and facilitating its mechanical clearance. This dual function of glutathione precursor and mucolytic makes NAC uniquely valuable in the respiratory support context alongside quercetin and nettle.

Other Ingredients: Capsule (hypromellose and water), ascorbyl palmitate, and silica. Vegetarian capsule. Free from gluten, dairy, soy, GMOs, and common allergens.

---

Storage

Store in a cool, dry place. Keep tightly closed and out of reach of children.

---

Directions

Take 2 capsules daily, or as directed by your healthcare professional.Consult your healthcare professional before use. Individuals taking medication should discuss potential interactions with their healthcare professional. Do not use if tamper seal is damaged.

---

XYMOGEN Quercetin 20x Plus is a practitioner-trusted quercetin phytosome and respiratory support supplement available at SOLUDE Wellness & Beauty. It contains Vitamin C (Ascorbic Acid) 200 mg (222% DV), Quercetin Phospholipid (Quercefit) 250 mg, Nettle Extract (Urtica dioica and/or Urtica urens, leaves) 200 mg, and N-Acetyl-L-Cysteine 100 mg per 2-capsule serving, in a vegetarian hypromellose capsule with ascorbyl palmitate and silica. Quercefit provides up to 20 times greater quercetin bioavailability than standard quercetin. It is designed to support mast cell stability and healthy histamine balance, healthy nasal comfort and respiratory ease, healthy inflammatory response via NF-kB and COX enzyme modulation, potent antioxidant defense in mucosal and systemic tissue, glutathione synthesis via NAC, mucolytic mucus viscosity reduction via NAC, and immune readiness during seasonal environmental challenges. Vegan, free from gluten, dairy, soy, GMOs, and common allergens. NSF GMP-certified. 60 capsules, 30 servings. Take 2 capsules daily.