Can you take quercetin with magnesium? A Guide to Safe Supplementation

October 7, 2025 •

4 min read

More than half of Americans fall short of their daily magnesium needs from diet alone [1.5.2]. As people turn to supplements like magnesium and the flavonoid quercetin, many wonder, 'Can you take quercetin with magnesium?' This article explores the combined use of these popular supplements.

Quick Summary

Current information suggests no direct negative interactions exist between quercetin and magnesium supplements like magnesium glycinate or threonate. Combining them may offer synergistic antioxidant benefits, but potential for medication interactions exists for each supplement individually.

Key Points

No Known Direct Interactions: Current drug interaction checkers show no negative interactions between quercetin and common forms of magnesium like glycinate and threonate [1.2.1, 1.2.3].
Potential Synergy: Research suggests that quercetin's antioxidant activity may be enhanced when it forms a complex with magnesium [1.3.8].
Individual Drug Interactions: Both quercetin and magnesium can interact with numerous prescription medications independently, affecting their absorption or efficacy [1.6.1, 1.7.2].
Quercetin Interaction Risks: Quercetin may interact with blood thinners, blood pressure medications, and drugs processed by the liver [1.6.1, 1.6.3].
Magnesium Interaction Risks: Magnesium can reduce the absorption of antibiotics, bisphosphonates (for osteoporosis), and thyroid medication [1.7.2].
Professional Consultation is Key: Due to the potential for medication interactions, it is essential to consult a healthcare provider before combining these supplements [1.3.1].
Bioavailability Varies: Magnesium supplements come in various forms with different absorption rates; magnesium oxide has lower bioavailability than citrate or glycinate [1.5.5].

Understanding Quercetin and Magnesium

Quercetin is a plant pigment, specifically a flavonoid, found in many foods like onions, apples, berries, and green tea [1.4.3]. It is known for its powerful antioxidant and anti-inflammatory properties [1.4.7]. Research suggests it may help protect against a range of conditions, including heart disease, infections, and allergies [1.4.2, 1.4.6]. As an antioxidant, it helps protect cells from damage caused by free radicals [1.4.7].

Magnesium is an essential mineral, the fourth most abundant in the human body, crucial for over 300 enzymatic reactions [1.3.3, 1.5.6]. It plays a vital role in muscle and nerve function, blood sugar regulation, blood pressure control, and the synthesis of protein, bone, and DNA [1.5.3]. Despite its importance, many people do not consume enough magnesium through their diet, leading them to consider supplementation [1.5.2].

Can You Take Quercetin and Magnesium Together?

Based on available data, there are no known direct negative interactions between quercetin and common forms of magnesium supplements, such as magnesium glycinate and magnesium threonate [1.2.1, 1.2.3]. This suggests that taking them together is generally considered safe for most healthy individuals. However, the absence of documented interactions does not definitively mean none exist, and it's always recommended to consult a healthcare provider before starting any new supplement regimen [1.3.1].

Interestingly, some research points towards a synergistic relationship. Quercetin has metal-chelating properties, meaning it can bind with metal ions like magnesium to form a complex [1.3.6, 1.3.8]. One study found that when quercetin formed a complex with magnesium, its free radical scavenging (antioxidant) activity actually increased [1.3.8]. This suggests that combining them might enhance their antioxidant potential. Some supplement manufacturers have even begun offering products that combine magnesium glycinate with quercetin for these synergistic benefits [1.3.3].

Scientific Insights

One older study noted that quercetin can inhibit a membrane-associated magnesium-dependent enzyme in certain white blood cells [1.2.4]. However, this effect was observed in a lab setting with specific cell types and may not translate to a significant negative interaction when taking oral supplements. The broader consensus from drug interaction checkers and recent studies indicates a low risk of adverse effects from the combination itself [1.2.1, 1.2.3].

Potential Drug Interactions for Each Supplement

While quercetin and magnesium may be safe to take together, each supplement can interact with various medications. It is crucial to be aware of these individual interactions.

Quercetin Drug Interactions

Quercetin can interact with several types of medications. Because it may lower blood pressure and slow blood clotting, it's important to be cautious if you are already taking medications for these conditions [1.3.7, 1.6.3].

Blood Thinners (Anticoagulants): Taking quercetin with drugs like warfarin or aspirin may increase the risk of bleeding [1.6.2, 1.6.3].
Blood Pressure Medications: Combining quercetin with antihypertensive drugs could cause blood pressure to drop too low [1.3.7, 1.6.3].
Antibiotics: Quercetin can interact with quinolone antibiotics [1.6.1].
Cyclosporine: This immune-suppressing drug's metabolism can be affected by quercetin [1.6.1].
Medications Processed by the Liver: Quercetin may alter how the liver processes certain drugs [1.6.1]. It can affect the P-glycoprotein (MDR1) efflux transporter, which is involved in the metabolism of numerous drugs, including some chemotherapy agents like everolimus and topotecan [1.6.7].

Magnesium Drug Interactions

Magnesium can affect the absorption of other drugs and be impacted by certain medications.

Antibiotics: Magnesium can bind to tetracycline and fluoroquinolone antibiotics in the stomach, reducing their absorption and effectiveness. It's recommended to take these antibiotics at least two hours before or four to six hours after a magnesium supplement [1.7.2].
Bisphosphonates: Used for osteoporosis, these drugs (e.g., alendronate) should be taken at least two hours apart from magnesium to ensure proper absorption [1.7.2].
Diuretics (Water Pills): Some diuretics (loop and thiazide) can increase magnesium loss through urine, while others (potassium-sparing) can cause the body to retain too much magnesium [1.7.2].
Proton Pump Inhibitors (PPIs): Long-term use of PPIs like omeprazole and lansoprazole can lead to low magnesium levels [1.7.6].
Thyroid Medication (Levothyroxine): Magnesium can reduce the absorption of thyroid medication, so they should be taken several hours apart [1.7.2].
Gabapentin: Magnesium can lower the absorption of gabapentin by 20% to 40%. It's advised to wait at least 2 hours after taking magnesium before taking gabapentin [1.7.1].

Comparison of Quercetin and Magnesium


Feature	Quercetin	Magnesium
Type	Flavonoid (plant pigment) [1.4.3]	Essential Mineral [1.5.4]
Primary Benefits	Antioxidant, anti-inflammatory, allergy relief, heart health support [1.4.2, 1.4.7]	Muscle/nerve function, blood pressure/sugar regulation, bone health [1.5.3]
Common Forms	Capsules, often combined with Vitamin C or bromelain for better absorption [1.4.2]	Glycinate, Citrate, Oxide, Threonate. Forms differ in bioavailability [1.5.2, 1.5.5]
Side Effects	Headache, nausea, tingling at high doses (>1g/day); potential kidney issues [1.4.2, 1.4.3]	Diarrhea, nausea, abdominal cramping, especially with oxide form [1.5.3, 1.5.5]
Key Interactions	Blood thinners, blood pressure meds, some antibiotics, cyclosporine [1.6.1, 1.6.3]	Certain antibiotics, bisphosphonates, diuretics, PPIs, thyroid meds [1.7.2]

Conclusion

Currently, there is no evidence to suggest a harmful interaction between quercetin and magnesium supplements when taken by healthy individuals. In fact, some research indicates they may work synergistically to enhance antioxidant activity [1.3.8]. However, both supplements have a significant list of potential interactions with prescription medications. It is essential to consider each supplement's interaction profile independently. The most crucial step before combining quercetin, magnesium, or any new supplements is to consult with a healthcare provider. They can review your current medications and health status to provide personalized advice and ensure your supplementation is both safe and effective.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any new supplement or medication.

Authoritative Link: National Institutes of Health - Magnesium Fact Sheet for Health Professionals

Frequently Asked Questions

Yes, it is generally considered safe. Drug interaction databases show no known interactions between quercetin and magnesium glycinate [1.2.1]. However, you should always consult your doctor first.

Some studies suggest a synergistic effect, where the antioxidant capacity of quercetin is increased when it binds with magnesium [1.3.8]. Some supplements are now formulated with both ingredients for this reason [1.3.3].

There is no specific recommended time to take them together. However, to avoid potential interactions with other medications, it's crucial to space them out. For example, some antibiotics and thyroid medications should be taken several hours apart from magnesium [1.7.2].

Yes, quercetin can interact with several medications, including blood thinners (like warfarin), blood pressure drugs, certain antibiotics, and cyclosporine [1.6.1, 1.6.2]. It may increase the risk of bleeding or cause blood pressure to drop too low when combined with these drugs [1.6.3].

Magnesium can interfere with the absorption of certain antibiotics (tetracyclines, fluoroquinolones), bisphosphonates for osteoporosis, and thyroid medications [1.7.2]. It can also interact with diuretics and proton pump inhibitors [1.7.6].

You should be cautious. Magnesium can have a mild blood-pressure-lowering effect. Combining it with blood pressure medications like calcium channel blockers could potentially cause your blood pressure to become too low. Consult your healthcare provider for monitoring [1.5.3, 1.7.2].

High doses of quercetin, typically over 1,000 mg per day, can cause headaches, nausea, and tingling sensations. There are also concerns that very high doses could potentially cause kidney damage [1.4.2, 1.4.3].