Quercetin is an amazing nutrient which may increase your testosterone, lifespan, endurance and immune system!
Technically a “plant pigment” which is why it is found in several dark vegetables and fruits, quercetin is highly regarded as a fierce antioxidant, fighting both free radical damage and inflammation within the body.
Increases in V02 Max
In a recent scientific case study, 12 participants were given 1,000 mg of quercetin daily for 7 days. These participants realized a 3.9% increase in VO2 Max and perhaps most astonishing, the subjects didn’t even exercise during the case study. (1)
We have to point out, however, 2 other human studies showed absolutely no benefit to endurance performance in either sprinting or cycling (2, 3). So don’t run out to buy quercetin sold on the idea it’s going to make you the next Spartan World Champion.
How Quercetin Effects Testosterone
We need to be clear that no human case studies on quercetin have shown a boost in testosterone to date but we couldn’t find a case study attempting to measure that either.
Quercetin does appear to inhibit an enzyme called UGT2B17 which converts testosterone into a molecule known as testosterone glucuronide.
Testosterone glucuronide is excreted via the kidneys and your urine so supplementation may help keep more of your testosterone in your system instead of being peed out. (4)
Of course, here at iTestosterone, we would like to see some actual human case studies done before we get too excited, but it seems very promising so far.
In all of the human studies we could find showing positive benefit to supplementation, at minimum, 500 mg daily was administered. However, doses between 1,000 – 2,000 mg were most commonly taken.
Foods Naturally High in Quercetin
- Onions (especially raw red onions)
- Red wine (but not too much alcohol)
- Dark Cherries and Berries
- Cruciferous vegetables
- Leafy greens
- Citrus fruits
- Dark Chocolate (especially cacao)
We do think quercetin may be able to help increase testosterone levels despite the lack of hard evidence so far.
Even if future studies turn out to show little, if any T boosting benefit, it seems to be a good overall supplement to take if you do not eat a lot of foods rich in the plant pigment.
Sticking to around 1,000 mg (1 gram) of daily supplementation seems ideal based on the human case studies to date.
Or you can just eat a lot of the foods mentioned above which are rich in quercetin and will provide a full spectrum of health benefits beyond that which quercetin can provide on its own.
- The dietary flavonoid quercetin increases VO(2max) and endurance capacity. Davis JM, Carlstedt CJ, Chen S, Carmichael MD, Murphy EA. – Link
- Effect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammation. Abbey EL, Rankin JW. – Link
- No effect of nutritional adenosine receptor antagonists on exercise performance in the heat. Cheuvront SN, Ely BR, Kenefick RW, Michniak-Kohn BB, Rood JC, Sawka MN. – Link
- Red wine and component flavonoids inhibit UGT2B17 in vitro Carl Jenkinson, Andrea Petroczi and Declan P Naughton – Link