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GNC Quercetin 500 MG

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Description
A potent bioflavonoid that protects against free radical damage*

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

Supplement Facts

As a dietary supplement, take one caplet daily. For maximum support, take as directed every day.

Serving Size 1 Caplet
Servings Per Container 60
Amount Per Serving % DV
Quercetin (as Quercetin Dihydrate) 500.00 mg **
** Daily Value (DV) not established

Other Ingredients: Cellulose, Food Glaze

No Sugar, No Artificial Colors, No Artificials Flavors, No Preservatives, Sodium Free, No Wheat, No Gluten, No Soy, No Diary, Yeast Free

Distributed by: General Nutrition Corporation Pittsburgh, PA 15222

Health Notes

Quercetin

Quercetin
This nutrient has been used in connection with the following health goals
  • Reliable and relatively consistent scientific data showing a substantial health benefit.
  • Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
  • For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary "Star-Rating" system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:

Prostatitis
Dose: 1,000 mg daily
Quercetin has anti-inflammatory and antioxidant effects and may reduce symptoms of chronic prostatitis.(more)
Allergies and Sensitivities
Dose: Refer to label instructions
Test tube and animal studies have found some effects from natural antihistamines such as the flavonoid quercetin, though no clinical research has shown whether these substances can specifically reduce allergic reactions. (more)
Asthma
Dose: Refer to label instructions
Quercetin, a flavonoid found in many plants, has an inhibiting action on lipoxygenase, an enzyme that contributes to problems with asthma. (more)
Hay Fever
Dose: Consult a qualified healthcare practitioner
Quercetin is an increasingly popular treatment for hay fever.(more)
Atherosclerosis
Dose: Refer to label instructions
Quercetin, a flavonoid, protects LDL cholesterol from damage.(more)
Edema
Dose: Refer to label instructions
In one study, the flavonoid quercetin corrected abnormal capillary permeability (leakiness), an effect that might improve edema.(more)
Type 2 Diabetes
Dose: Refer to label instructions
Quercetin may be helpful for its ability to reduce levels of sorbitol-a sugar that accumulates in cells and damages the nerves, kidneys, and eyes of people with diabetes.(more)
Type 1 Diabetes
Dose: Refer to label instructions
Quercetin may be helpful for its ability to reduce levels of sorbitol-a sugar that accumulates in cells and damages the nerves, kidneys, and eyes of people with diabetes.(more)
Childhood Diseases
Dose: Refer to label instructions
Quercetin is a flavonoid that has shown particularly strong antiviral properties in the test tube.(more)
Gout
Dose: Refer to label instructions
In test tube studies, quercetin, a flavonoid, has inhibited an enzyme involved in the development of gout.(more)
Cataracts
Dose: Refer to label instructions
The flavonoid quercetin may help protect against cataracts by blocking sorbitol accumulation in the eye.(more)
Athletic Performance and Post-Exercise Infection
Dose: 500 mg twice a day
In one study, quercetin lowered the incidence of upper respiratory tract infections in athletes following intensive exercise. (more)
Prostatitis
Dose: 1,000 mg daily

Quercetin, a flavonoid with anti-inflammatory and antioxidant effects, has recently been reported to improve symptoms of NBP and PD. An uncontrolled study reported that 500 mg of quercetin twice daily for at least two weeks significantly improved symptoms in 59% of men with chronic prostatitis.1 These results were confirmed in a double-blind study, in which similar treatment with quercetin for one month improved symptoms in 67% of men with NBP or PD.2 Another uncontrolled study combined 1,000 mg per day of quercetin with the enzymes bromelain and papain, resulting in significant improvement of symptoms.3 Bromelain and papain promote absorption of quercetin and have anti-inflammatory effects as well.4

References

1. Shoskes DA. Use of the bioflavonoid quercetin in patients with longstanding chronic prostatitis. JANA 1999;2:36-9.

2. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology 1999; 54:960-3.

3. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology 1999; 54:960-3.

4. Izaka K, Yamada M, Kawano T, Suyama T. Gastrointestinal absorption and anti-inflammatory effect of bromelain. Jpn J Pharmacol 1972;22:519-34.

Allergies and Sensitivities
Dose: Refer to label instructions

Many of the effects of allergic reactions are caused by the release of histamine, which is the reason antihistamine medication is often used by allergy sufferers. Some natural substances, such as vitamin C1, 2 and flavonoids,3 including quercetin,4, 5 have demonstrated antihistamine effects in test tube, animal, and other preliminary studies. However, no research has investigated whether these substances can specifically reduce allergic reactions in humans.

References

1. Johnston CS, Retrum KR, Srilakshmi JC. Antihistamine effects and complications of supplemental vitamin C. J Am Diet Assoc 1992;92:988-9.

2. Johnston S, Martin LJ, Cai X. Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. J Am Coll Nutr 1992;11:172-6.

3. Gabor M. Anti-inflammatory and anti-allergic properties of flavonoids. Prog Clin Biol Res 1986;213:471-80 [review].

4. Middleton E, Drzewieki G. Naturally occurring flavonoids and human basophil histamine release. Int Arch Allergy Appl Immunol 1985;77:155-7.

5. Amella M, Bronner C, Briancon F, et al. Inhibition of mast cell histamine release by flavonoids and bioflavonoids. Planta Medica 1985;51:16-20.

Asthma
Dose: Refer to label instructions

Quercetin, a flavonoid found in most plants, has an inhibiting action on lipoxygenase, an enzyme that contributes to problems with asthma.1 No clinical trials in humans have confirmed whether quercetin decreases asthma symptoms. Some doctors are currently experimenting with 400 to 1,000 mg of quercetin three times per day.

References

1. Welton AF, Tobias LD, Fiedler-Nagy C, et al. Effect of flavonoids on arachidonic acid metabolism. Prog Clin Biol Res 1986;213:231-42.

Hay Fever
Dose: Consult a qualified healthcare practitioner

Quercetin is an increasingly popular treatment for hay fever even though only limited preliminary clinical research has suggested that it is beneficial to hay fever sufferers.1

References

1. Balabolkin II, Gordeeva GF, Fuseva ED, et al. Use of vitamins in allergic illnesses in children. Vopr Med Khim 1992;38:36-40.

Atherosclerosis
Dose: Refer to label instructions

Quercetin, a flavonoid, protects LDL cholesterol from damage.1 While several preliminary studies have found that eating foods high in quercetin lowers the risk of heart disease,2, 3, 4 the research on this subject is not always consistent,5 and some research finds no protective link.6 Quercetin is found in apples, onions, black tea, and as a supplement. In some studies, dietary amounts linked to protection from heart disease are as low as 35 mg per day.

References

1. Ronzio RA. Antioxidants, nutraceuticals and functional foods. Townsend Letter for Doctors and Patients 1996;Oct:34-5 [review].

2. Hertog MGL, Feskens EJM, Hollman PCH, et al. Dietary antioxidant flavonoids and risk of coronary heart disease: the Zutphen Elderly Study. Lancet 1993;342:1007-11.

3. Hertog MGL, Kromhout D, Aravanis C, et al. Flavonoid intake and long-term risk of coronary heart disease and cancer in the Seven Countries Study. Arch Intern Med 1995;155:381-6.

4. Knekt P, Jarvinen R, Reunanen A, Maatela J. Flavonoid intake and coronary mortality in Finland: a cohort study. BMJ 1996;312:478-81.

5. Rimm EB, Katan MB, Ascherio A, et al. Relation between intake of flavonoids and risk for coronary heart disease in male health professionals. Ann Intern Med 1996; 125:384-9.

6. Hertog MGL, Sweetnam PM, Fehily AM, et al. Antioxidant flavonols and ischemic heart disease in a Welsh population of men: the Caerphilly Study. Am J Clin Nutr 1997;65:1489-94.

Edema
Dose: Refer to label instructionsBecause coumarin, hydroxyethylrutosides, and diosmin are not widely available in the United States, other flavonoids, such as quercetin, rutin, or anthocyanosides (from bilberry), have been substituted by doctors in an attempt to obtain similar benefits. The effect of these other flavonoids against edema has not been well studied. Also, optimal amounts are not known. However, in one study, quercetin in amounts of 30-50 mg per day corrected abnormal capillary permeability (leakiness),1 an effect that might improve edema. A similar effect has been reported with rutin at 20 mg three times per day.2 Doctors often recommend 80-160 mg of a standardized extract of bilberry, three times per day.
References

1. Griffith JQ. Clinical application of quercetin: preliminary report. J Am Pharm Assoc 1953;42:68-9.

2. Shanno RL. Rutin: a new drug for the treatment of increased capillary fragility. Am J Med Sci 1946;211:539-43.

Type 2 Diabetes
Dose: Refer to label instructionsDoctors have suggested that quercetin might help people with diabetes because of its ability to reduce levels of sorbitol-a sugar that accumulates in nerve cells, kidney cells, and cells within the eyes of people with diabetes-and has been linked to damage to those organs.1 Clinical trials have yet to explore whether quercetin actually protects people with diabetes from neuropathy, nephropathy, or retinopathy.
References

1. Gaby A. Preventing complications of diabetes Townsend Letter 1985;32:307 [editorial].

Type 1 Diabetes
Dose: Refer to label instructionsDoctors have suggested that quercetin might help people with diabetes because of its ability to reduce levels of sorbitol-a sugar that accumulates in nerve cells, kidney cells, and cells within the eyes of people with diabetes and has been linked to damage to those organs.1 Clinical trials have yet to explore whether quercetin actually protects people with diabetes from nerve damage (neuropathy), nephropathy, or eye damage (retinopathy).
References

1. Gaby A. Preventing complications of diabetes Townsend Letter 1985;32:307 [editorial].

Childhood Diseases
Dose: Refer to label instructions

Flavonoids are a group of compounds found in some plant foods and medicinal herbs. An antiviral action of some flavonoids has been observed in a number of test tube experiments.1, 2, 3, 4, 5Quercetin, one of the flavonoids, has shown particularly strong antiviral properties in the test tube;6, 7, 8 however, one study did not find quercetin to be of benefit to mice with a viral infection.9 It is not known whether flavonoids can be absorbed in amounts sufficient to exert an antiviral effect in humans, and therefore their possible role in the treatment of childhood exanthems remains unknown.

References

1. Vrijsen R, Everaert L, Boeye A. Antiviral activity of flavones and potentiation by ascorbate. J Gen Virol 1988;69:1749-51.

2. Debiaggi M, Tateo F, Pagani L, et al. Effects of propolis flavonoids on virus infectivity and replication. Microbiologica 1990;13:207-13.

3. Fesen MR, Kohn KW, Leteurtre F, Pommier Y. Inhibitors of human immunodeficiency virus integrase. Proc Natl Acad Sci 1993;90:2399-403.

4. Amoros M, Simoes CM, Girre L, et al. Synergistic effect of flavones and flavonols against herpes simplex virus type 1 in cell culture. Comparison with the antiviral activity of propolis. J Nat Prod 1992;55:1732-40.

5. Spedding G, Ratty A, Middleton E Jr. Inhibition of reverse transcriptases by flavonoids. Antiviral Res 1989;12:99-110.

6. Kaul TN, Middleton E Jr, Ogra PL. Antiviral effect of flavonoids on human viruses. J Med Virol 1985;15:71-9.

7. Mucsi I, Pragai BM. Inhibition of virus multiplication and alteration of cyclic AMP level in cell cultures by flavonoids. Experientia 1985;41:930-1.

8. Ohnishi E, Bannai H. Quercetin potentiates TNF-induced antiviral activity. Antiviral Res 1993;22:327-31.

9. Esanu V, Prahoveanu E, Crisan I, Cioca A. The effect of an aqueous propolis extract, of rutin and of a rutin-quercetin mixture on experimental influenza virus infection in mice. Virologie 1981;32:213-5.

Gout
Dose: Refer to label instructions

In test tube studies, quercetin, a flavonoid, has inhibited an enzyme involved in the development of gout.1, 2 However, it is not known whether taking quercetin by mouth can produce high enough quercetin concentrations in the body to achieve these effects. Although human research is lacking, some doctors recommend 150-250 mg of quercetin three times per day (taken between meals).

References

1. Bindoli A, Valente M, Cavallini L. Inhibitory action of quercetin on xanthine oxidase and xanthine dehydrogenase activity. Pharmacol Res Commun 1985;17:831-9.

2. Busse W, Kopp D, Middleton E. Flavonoid modulation of human neutrophil function. J Allergy Clin Immunol 1984;73:801-9.

Cataracts
Dose: Refer to label instructions

The flavonoidquercetin may also help by blocking sorbitol accumulation in the eye.1 This may be especially helpful for people with diabetes, though no clinical trials have yet explored whether quercetin actually prevents diabetic cataracts.

References

1. Varma SD, Mizuno A, Kinoshita JH. Diabetic cataracts and flavonoids. Science 1977;195:205.

Athletic Performance and Post-Exercise Infection
Dose: 500 mg twice a day In a double-blind study of trained athletes, the incidence of upper respiratory tract infections following a three-day period of intensive exercise was significantly lower in people who took quercetin than in those who received a placebo (5% versus 45%).1 The amount of quercetin used was 500 mg twice a day, beginning three weeks before, and continuing for two weeks after, the intensive exercise.
References

1. Nieman DC, Henson DA, Gross SJ, et al. Quercetin reduces illness but not immune perturbations after intensive exercise. Med Sci Sports Exerc 2007;39:1561-9.

Quercetin belongs to a class of water-soluble plant pigments called flavonoids.

Copyright 2014 Aisle7. All rights reserved. Aisle7.com

The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2015.

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5.0

awesome!

By fcdadino

from Marlton, NJ

About Me Health Conscious

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Pros

  • Easy on Stomach
  • Easy To Swallow
  • Effective
  • Simple To Take

Cons

  • None

Best Uses

  • Men
  • Women

Comments about GNC Quercetin 500 MG:

tremendous... very satisfied.

(6 of 6 customers found this review helpful)

 
5.0

I would buy this product again and have!

By sheila.weller

from St, Louis, MO

About Me Budget Buyer

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Pros

  • Easy To Use
  • Effective
  • Good Value

Cons

    Best Uses

    • Daily Use
    • Men
    • On-the-go
    • Women

    Comments about GNC Quercetin 500 MG:

    Suffered from allergies all year round. After one day noticed allergies going away. Stopped taking antihistimine, decongestant and also Prilosec for heart burn. It calms digestion and respitory. I would not have believed it. ABSOLUTELY RECOMMEND QUERCETIN!

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