Can you take quercetin and fisetin together

Quercetin and fisetin are both natural flavonoids found in fruits and vegetables. They're popular in the supplement world for their antioxidant and anti-inflammatory effects. A lot of people wonder if it's safe or even useful to take them together. Short answer? Yes, you can — and in some cases, combining them might even be a good idea.

Quercetin is found in apples, onions, and green tea. It's known for helping with allergies, boosting immunity, and supporting heart health. Fisetin, on the other hand, is a lesser-known compound found in strawberries and mangoes. It’s been studied for brain support, anti-aging effects, and its ability to help clear out senescent cells — the ones that stop dividing but don’t die off like they should.

These two compounds work in slightly different ways, which is why taking them together can be complementary. Quercetin is better known for immune and allergy support, while fisetin is often used for cognitive health and longevity. Both have antioxidant properties, but they don’t cancel each other out or compete in a harmful way when used together.

One of the biggest concerns with any supplement combo is interaction, but so far, there’s no strong evidence showing negative interactions between quercetin and fisetin. That said, both supplements can affect how your body processes certain medications — especially blood thinners or drugs metabolized by the liver. If you’re on meds, it’s a smart move to talk to your healthcare provider first.

As for dosing, there’s no one-size-fits-all. A typical quercetin dose ranges from 250 mg to 1,000 mg per day. Fisetin doses for longevity or senolytic purposes are usually higher — often in the range of 500 mg to 1,000 mg per day, but some people do higher doses on a short-term basis. They’re sometimes taken with fat (like in a meal or with fish oil) to boost absorption.

Stacking quercetin and fisetin isn’t uncommon among biohackers or people interested in anti-aging strategies. Some even pair them with other compounds like resveratrol, curcumin, or NMN. If you’re just getting started, try taking each one on alternate days first, then see how your body reacts before combining them daily.

While both are generally well-tolerated, high doses of quercetin might cause headaches or upset stomach in some people. Fisetin is usually tolerated well, but since it’s less studied in humans, staying within moderate limits is a good idea unless you're following a researched protocol.

If you’re looking to support your immune system, brain health, or healthy aging, combining quercetin and fisetin could be a great option. Just make sure to source high-quality supplements and take them consistently if you want to see any long-term benefits.