Quercetin Side Effects

Quercetin Side Effects

6 minute read

Healthy eating and exercise are essential for your well-being. Still, it can be difficult to consistently give your body everything it needs to stay healthy and fortified against disease and signs of aging. An easy way to maximize the nutritional value of your overall diet is by taking supplements, and plant-based vitamins and additives provide unique benefits to human health. 


Quercetin is one plant-based supplement option that can bring valuable support to people’s cardiovascular and immune systems. Health-conscious consumers will want to know about quercetin’s potential benefits and uses, as well as any side effects it can cause before they start taking it regularly.

What Is Quercetin?

Quercetin is a type of flavonoid in fruits and vegetables that is sometimes used as a dietary supplement due to its immune-boosting properties. 


Flavonoids are naturally-occurring plant pigments and are often cited as the health-boosting component in wine and dark chocolate. 


Quercetin, in particular, often appears in:


  • Grapes and red wine

  • Cherries

  • Berries

  • Apples

  • Citrus fruits

  • Black tea


You can readily find it in powder or pill form, typically in 500mg doses, or you can get it injected by a healthcare physician at the patient’s request.

Quercetin Benefits

Quercetin can provide a diverse range of benefits to the human body and is mainly known for reducing inflammation and damage from free radicals. 


Some of the most common perks of taking quercetin include:


  • Allergy and asthma relief

  • Prevention of respiratory infections

  • Lower blood pressure and reduced risk of heart disease 

  • Improved physical endurance

Recommended Dosage

People can naturally absorb quercetin as part of a balanced diet that includes plenty of fruits and vegetables. Because it is present in so many different plant-based foods, anyone who eats healthy meals regularly will consume some amount of quercetin. 


The most reliable way to get this flavonoid is through dietary supplementation. Quercetin pills typically come in 500mg doses, and 1000mg is the highest recommended daily amount for adults. Alternative options include powders and intravenous injection, but finding the supplement in pill form is most accessible. 


Children can safely take up to half recommended adult dosage, meaning no more than 500mg per day. 

Quercetin Side Effects and Potential Risks

Quercetin supplements rarely cause harmful side effects, and the most common are headaches and tingling in the arms or legs. 


The tingling sensation is generally mild but may become severe in some people, especially if they consume large amounts of quercetin each day. These side effects can vary depending on a person’s overall health and any medications they take along with quercetin. 


Allergic reactions are uncommon, but check the label on supplements before you buy them to ensure they do not contain inactive ingredients that you are allergic to.


Nausea and vomiting sometimes occur with intravenous injection but are not associated with oral supplements taken in appropriate quantities. High doses, meaning one gram or more per day, have the potential to cause kidney damage over time. It is dangerous to take a more significant amount than recommended by a doctor or the supplement manufacturer, as with all supplements. 


Because quercetin is naturally present in many foods, you can get too much of it if you take a supplement. Taking 500-1000mg a day or less is optimal, mainly if you eat a lot of red-colored fruits and leafy greens since these contain the highest amount of naturally-occurring flavonoids in general. 


It is best to consult with a doctor before you start taking quercetin or any other supplement to ensure you are getting the appropriate amount for your body’s needs without causing negative interactions with other medications you are on. 

Who Should Avoid Taking Quercetin?

Quercetin may interfere with medications taken for liver function and should not be used by chemotherapy patients. Talk with your doctor about any medications you are on or if you have ongoing health concerns that you think may be affected by quercetin before you begin taking any supplements.


There is currently not much information available on how this flavonoid affects pregnant people. Hence, it is best to avoid supplementing with it if you are pregnant or planning to become pregnant. 


Children younger than 18 should always consume less quercetin than adults and never more than 500mg total in one day. Otherwise, they may begin to show symptoms of the above side effects due to overdose. 

How to Supplement With Quercetin Safely

You should always consult a doctor if you have concerns about adding a new supplement to your diet. Buy your supplements from a reliable source, such as Luma Nutrition, to ensure you are getting a genuine product made with high-quality active ingredients. 


You’ll also want to avoid taking more than 1000mg a day unless instructed otherwise by a healthcare or dietary physician. Avoid taking quercetin if you are on liver medication or antibiotics, if you are undergoing chemotherapy, or if you are pregnant. Children under age 18 should stick to small doses of 500mg or less per day. 


The most common quercetin side effects are mild, and the substance is considered safe for consumption overall. As long as you stick to the recommended dose on the supplement’s label or the one provided by your doctor, there should be little to no risk involved with quercetin. 


If you have any concerns about developing an adverse reaction to this supplement, start with a small dosage (250mg or less daily) and see how it affects your body after a couple of weeks. 


Using quercetin as a dietary supplement is a relatively new practice, so most of the studies on it have only come out in recent years or are still ongoing. 


So far, most research concludes that quercetin shows promise as an ingredient to help boost physical performance and reduce inflammation. Adverse quercetin side effects are rare as long as this flavonoid is taken in small doses. 

Suppose you’re interested in adding quercetin to your daily regime. In that case, Luma Nutrition sells easy-to-swallow capsules that come in the perfect dosage with the addition of bromelain for further inflammation reduction and immune-boosting benefits.

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