Across 280 first-hand reports, people mentioned a side effect 13 times (about 5 per 100 reports). The most common: insomnia, jitteriness, anxiety. User reports show what people notice — they can't tell you whether Quercetin is safe for you.
“The Thorne Quercetin has helped me a lot with seasonal allergies. I'd go as far as to say it had been more effective for me than either Claritin or Zyrtec.”
“I like quercetin but had to stop due to joint/tendon pain. I narrowed it down to that. It worked amazing for my mental clarity, energy and allergic rhinitis”
“Quercetin has helped my daily allergy symptoms to the point that I no longer need Allegra”
“Quercetin gives me bad insomnia. Like, night owl energy. I still take it because I am a woman of science and I like to experiment, but the benefits are yet to be realized”
“quercetin makes me uncomfortably wired; definitely could fuel anxiety.”
Conclusion: Supplementation of some but not all micronutrients may benefit cardiometabolic health. This study highlights the importance of micronutrient diversity and the balance of benefits and risks to promote and maintain cardiovascular health in diverse populations. (Antioxidant Supplementation in the Prevention and Treatment of Cardiovascular Diseases; CRD42022315165).