Quercetin

Quercetin is a plant compound from the group of flavonoids that are widely distributed in nature. It is found in many fruits, vegetables, grains, leafy green vegetables, wine and tea. Quercetin is known for its antioxidant properties, so it may help protect the body's cells from damage caused by free radicals.

Quercetin is also being investigated as a potential agent for treating or preventing a variety of diseases, including cardiovascular disease, allergies, some forms of cancer, and diseases associated with inflammation. It has antihistamine properties, making it useful for allergic reactions, and may have anti-inflammatory effects.

However, despite the promising results of preliminary studies, more scientific work will be needed to confirm the efficacy and safety of quercetin when used as an adjunct to conventional treatments. It is available in supplement form, but as with any dietary supplement, it is recommended that you consult with a physician before taking it, especially if you have a chronic condition or are taking other medications.

Indications Quercetin

1. Antioxidant Support: Quercetin has strong antioxidant properties that help protect cells from free radicals, preventing oxidative stress and inflammation.
2. Support heart health: Studies show that quercetin may help lower blood cholesterol levels and improve vascular function, which may be beneficial for heart health.
3. ImmuneSystem Support: Quercetin has immunomodulatory properties and may help strengthen the immune system by boosting its defenses.
4. Anti-allergic effects: Some studies suggest that quercetin may help reduce allergy symptoms such as runny nose, itching, and coughing.
5. Anti-inflammatory: Quercetin has anti-inflammatory properties and may help reduce inflammation in the body.
6. Support skin health: Quercetin may help improve skin health due to its antioxidant and anti-inflammatory properties.

Release form

1. Capsules and tablets: This is the most common form of quercetin. It is convenient for accurate dosing and ease of administration. Capsules may contain quercetin in pure form or in combination with other flavonoids or additives designed to improve its absorption or action.
2. Powder: Quercetin in powder can be added to smoothies, juices or water. This form is suitable for people who prefer individualized dosage adjustments or have difficulty swallowing tablets.
3. Liquid extracts: The liquid form of quercetin provides fast absorption and allows for easy dosage adjustment. It may be preferred for children or adults who have difficulty taking solid supplements.
4. Chewable tablets: Chewable tablets in different flavors may be used to improve the taste and make quercetin easier to take, especially in children.
5. Ointments and creams for external use: Quercetin can also be found in some ointments and creams intended for external use, such as to reduce skin inflammation or to treat certain skin conditions.

Pharmacodynamics

1. Antioxidant Properties: Quercetin is a strong antioxidant that can neutralize free radicals in the body. It protects cells from oxidative stress, which can help in preventing various diseases associated with cell damage such as cancer and cardiovascular diseases.
2. Anti-Inflammatory Properties: Quercetin has anti-inflammatory properties, helping to reduce levels of inflammatory mediators in the body. It may help in reducing inflammation in tissues and joints, which can be beneficial for conditions such as arthritis and asthma.
3. Anti-allergic properties: Quercetin may help reduce the production and release of histamine and other substances associated with allergic reactions. This makes it useful in treating allergies and seasonal allergic rhinitis.
4. Anti-carcinogenic properties: Studies show that quercetin may have anti-tumor effects and is able to inhibit the growth and development of tumors. It may help in reducing the risk of cancer and slow the progression of cancerous processes.
5. Antibacterial Properties: Quercetin has antibacterial properties and can help fight a variety of bacterial infections. It can inhibit the growth and development of bacteria, making it useful in treating urinary tract infections, respiratory infections, and other conditions.

Pharmacokinetics

1. Absorption: Quercetin is normally absorbed from the gastrointestinal tract after oral administration. However, its absorption may be limited due to its limited water solubility.
2. Bioavailability: The bioavailability of quercetin when taken orally is generally low due to its limited solubility and extensive metabolism in the liver.
3. Metabolism: Quercetin is metabolized in the liver to form various metabolites. The main metabolites of quercetin are glucuronides and sulfates.
4. Distribution: Quercetin may be distributed in various tissues and organs of the body, including the liver, kidneys, lungs, and brain, but its concentration in them may not be high.
5. Excretion: Quercetin and its metabolites are excreted from the body mainly through the kidneys as glucuronides and sulfates.
6. Half-life (T1/2): The half-life of quercetin can be relatively short, lasting several hours.
7. Protein binding: Quercetin may bind to plasma proteins, which may affect its distribution and metabolism.

Dosing and administration

• For adults: The usual dosage of quercetin is 500 mg to 1,000 mg per day, divided into two doses. Some studies have used doses up to 1500 mg per day, but high doses should only be taken under a doctor's supervision.
• For children: There are no specific recommendations on the dosage of quercetin for children, so before giving quercetin to a child, be sure to consult your pediatrician.

Specific Cases

• To improve heart and vascular health and for general antioxidant benefits: Recommended doses are typically in the range of 500 mg to 1,000 mg per day.
• For allergies: Dosages can vary, but often start at 500 mg per day and increase to 1000 mg if needed.
• Inflammatory processes and diseases: The dosage and regimen may vary depending on the specific disease and its severity.

Tips for Use

• With or without food: Quercetin can be taken with or without food, but taking it with food may help reduce the likelihood of gastrointestinal upset.
• Duration of intake: The duration of quercetin intake may depend on the purpose of intake and individual body response. In some cases quercetin is taken in courses, in others as a regular supplement.

Important Moments

• A doctor should be consulted before starting to take quercetin, especially on a regular basis or in high doses.
• Carefully read the manufacturer's instructions on the supplement packaging, as dosages and recommendations may vary.
• Tell your doctor about all supplements and medications you are taking to avoid possible interactions.

Use Quercetin during pregnancy

There is limited data on the safety of quercetin use during pregnancy. Scientific research on this topic is limited and there is insufficient data to draw definitive conclusions about its safety and efficacy during pregnancy.

If you are pregnant or planning a pregnancy and are considering using quercetin as a dietary supplement or as a therapeutic agent, it is important to discuss this with your doctor. He or she will be able to assess your individual situation, consider the benefits and risks of using quercetin during pregnancy, and make appropriate recommendations.

In general, it is recommended to be especially cautious with any dietary supplements or medications, including natural products, during pregnancy, as their effects on the developing fetus may not be well understood.

Contraindications

1. Hypersensitivity: Some people may show hypersensitivity or allergic reactions to quercetin. If allergic symptoms such as itching, hives, swelling or difficulty breathing occur, discontinue use and consult a physician.
2. Pregnancy and breastfeeding: There is insufficient data on the use of quercetin during pregnancy and breastfeeding, therefore, large doses of quercetin should be avoided during these periods without consulting a physician.
3. Interactions with medicines: Quercetin may interact with some medicines, including anticoagulants (e.g. Warfarin) and antiaggregants (e.g. Aspirin). This may alter the effects of the medications, so it is important to discuss taking quercetin with your doctor if you are taking any medications.
4. Digestive problems: Quercetin may cause stomach irritation or increased symptoms of heartburn in some people. People with sensitive digestive tracts should be cautious about taking quercetin.
5. Renal Problems: If there are serious kidney problems or kidney failure, taking quercetin may require medical supervision and dosage adjustment.
6. Children: There is insufficient data on the use of quercetin in children, therefore its use in children should be under the supervision of a physician.

Side effects Quercetin

1. Stomach Disorders: In some cases, quercetin may cause stomach discomfort, including pain, gas, and abdominal bloating.
2. Headache and tingling: Some people report headaches and tingling after taking quercetin.
3. Low blood pressure: Quercetin can affect blood pressure, which is especially important for people taking medication for high blood pressure, as it can cause levels to get too low.
4. Drug Interactions: Quercetin may interact with some medications, such as antibiotics and blood thinners, altering their effectiveness.

Overdose

1. Gastrointestinal disorders: Nausea, vomiting, diarrhea and other gastrointestinal disorders may occur.
2. Allergic reactions: In rare cases, allergic reactions such as itching, urticaria or Quincke's edema may occur.
3. Electrolyte disturbances: Quercetin overdose may lead to electrolyte imbalances, including blood potassium levels.
4. Migraine or headache: In some cases, taking quercetin in high doses may cause headache or migraine.
5. Other symptoms: Other symptoms such as drowsiness, weakness, dizziness, or insomnia may occur.

Interactions with other drugs

1. Anticoagulant drugs: Quercetin may increase the effect of anticoagulants (drugs that reduce blood clotting) such as warfarin or heparin, which may increase the risk of bleeding. Therefore, caution should be exercised when taking it at the same time.
2. Drugs that increase the risk of bleeding: Quercetin may increase the risk of bleeding when used concomitantly with other drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, and other drugs that also increase the risk of bleeding.
3. Drugs that increase blood potassium levels: Quercetin may increase blood potassium levels, so hyperkalemia may be a problem when combined with potassium-saving diuretics or other drugs that increase potassium levels in the body.
4. Drugs that increase blood calcium levels: According to some reports, quercetin may increase blood calcium levels, so it should be used with caution in patients with hypercalcemia or when taking calcium-increasing drugs concomitantly.
5. Blood pressure-increasing drugs: Quercetin may decrease blood pressure, therefore blood pressure should be monitored when taken concomitantly with antihypertensive drugs.
6. Drugs affecting the liver: Since quercetin may be metabolized in the liver, it should be taken with caution in patients with liver disease or while taking other drugs affecting liver function.

Storage conditions

1. Temperature: Quercetin should be stored at room temperature, which is usually between 15°C and 25°C (59°F to 77°F). Avoid storing the drug in places with extreme temperatures.
2. Humidity: The drug should be stored in a dry place to prevent clumping or sticking of the capsules.
3. Light: It is recommended to store quercetin in a dark place protected from direct sunlight to prevent decomposition of the active ingredients by light.
4. Packaging: Store quercetin in its original packaging or container to prevent inadvertent access and to protect it from external factors.
5. Availability to children: Ensure that quercetin is stored out of the reach of children to prevent accidental ingestion.