This bioflavonoid is a powerful antioxidant that protects our cells from damage by free radicals
Quercetin is one of my favourite natural compounds because it’s the most well-researched of the many bioflavonoids (a plant-based polyphenol). Quercetin is a true natural powerhouse found in many fruits and vegetables we eat daily, such as apples, onions, and berries. Quercetin was named after the oak tree, Quercus, as it was initially isolated from oak bark. This bioflavonoid is a powerful antioxidant that protects our cells from damage by free radicals. However, quercetin also supports heart health by improving blood flow and lowering blood pressure; it helps fight off viruses, eases allergies, and reduces inflammation in the brain.
Quercetin’s surprising benefit you might not know
A new meta-analysis of human randomized, controlled trials found that quercetin supplementation can improve muscle recovery after exercise that causes muscle damage. This analysis included data from 13 randomized, controlled trials involving 249 participants aged 15–29, all generally healthy. Most participants were trained individuals, and the exercise protocols used in the trials were designed to intentionally cause muscle damage. The quercetin dosage was typically 1000 mg per day, with the duration of supplementation varying from a single dose to six weeks.
Key findings: Quercetin reduced muscle soreness immediately and 24 hours after exercise, lowered levels of creatine kinase (a marker of muscle damage) at 24 and 48 hours post-exercise, and decreased oxidative stress after exercise – compared to placebo. Additionally, quercetin helped restore muscle strength faster and reduced lactate dehydrogenase levels (a marker of muscle damage) during recovery.
Limitations: While the findings are very promising, there were some variations between the studies because of differences in exercise protocols and analysis methods, which may affect the clarity of the results.
How quercetin may help with exercise performance and recovery
Reduces oxidative stress and inflammation: During and after intense exercise, the body triggers an inflammatory response that involves a complex molecular mechanism, for example, producing free radicals (reactive oxygen species [ROS]). While this initial inflammatory response helps with muscle repair, the body must efficiently resolve inflammation to avoid chronic issues. Quercetin can help balance inflammation by neutralizing excess free radicals, reducing oxidative damage, and thus speeding recovery (e.g., less muscle soreness). Balancing inflammation is key to healthy exercise adaptation.
Reduces muscle damage from intense exercise: Quercetin enhances antioxidant defences by boosting glutathione levels, lowering ROS, and strengthening cell membranes.
Supports muscle repair and adaptation: Quercetin may increase levels of certain growth factors (IGF-I and IGF-II) that are important for muscle repair and rebuilding after exercise-induced muscle damage.
Reduces muscle soreness and improves blood flow: Quercetin may help with pain; it activates certain brain receptors (GABA and serotonin) and reduces inflammation (cytokine production) in the body. It also boosts nitric oxide (NO) production, improving blood flow to muscles for better performance and recovery.
Bioavailability – foods and supplements
While quercetin shows promising results in lab studies (in vitro), these effects are often less impressive in human or animal studies. This is because quercetin (just like so many other polyphenols and flavonoids) is hard for our bodies to absorb when ingested orally, meaning only a small amount is available to be used. Additionally, people absorb and process quercetin differently. Thus, getting enough active quercetin from foods alone can be challenging, which is why supplementation with a highly bioavailable form can be beneficial
- As principal scientist, I’ve helped develop a new quercetin formulation (LipoMicel®) that boosts absorption in the body by up to 10 times
- Quercetin is considered safe when used as intended, with no side effects reported even at several grams per day in human or animal studies
- The typical quercetin dose for health benefits is 500–1000 mg/day
Supplements that pair well with quercetin for boosting exercise:
- Vitamin C and green tea extract enhance quercetin’s antioxidant effects
- Omega-3 fatty acids and curcumin reduce inflammation and support recovery
- BCAAs (branched-chain amino acids) and protein help with muscle repair and exercise-induced fatigue
- Regenerlife™ Mitochondrial Energy and Creatine support strength and performance
Remember that supplements can only give us a helpful health boost, but eating a variety of wholefoods rich in fibre and other phytonutrients is key for overall health.
