How much onion to increase testosterone? Perhaps none

If you look around on the internet, you’ll hear claims that onions increase testosterone, and all kinds of other statements like that.

Just how much onion does it take to increase testosterone? Well, the one study done on humans showed no major testosterone increase, but we can tell you how much the rats in the other studies ate.

To match what the rats ate, a person would need about 2 onions per day.

Doing the math

Here’s why. Most studies were done on rats. Studies usually used onion juice between 0.5 ml and 6 ml daily, per rat. (source) If that was a 670g male wistar rat, then equivalent amount of onion juice for a 180 lb man would be 61 ml to 731 ml of onion juice daily. 61 ml is something like as much as there is in 2/3 of an onion, and 731 ml is about as much as there is in a little under 8 onions. (These are all very rough estimates) To match the amount that most of the studies used, you’d probably eat about 2 onions worth of juice daily.

Don’t eat tons of onions though

But the real answer is that stuff like this really isn’t the ideal way to improve your health and hormones. As I mentioned, the study that fed humans onion extract found no major effect on testosterone. Being lean, sleeping enough, and eating a nutrient dense and natural diet are probably way more effective for increasing testosterone.

I also can’t say what eating 2 onions every day might do to your body, it might be hard on your digestion, and I know I would get sick of it quickly.

So how can we raise testosterone then?

However, it’s understandable that people are looking for testosterone boosting advice other than “get healthy,” since even healthy and fit people today seem to have lower testosterone than people in the past did. Our site has extensive discussion of the fall of testosterone levels over the years.

Why is testosterone low today, even in healthy and fit people? It probably isn’t because we eat less onions… We aren’t sure what exactly is making testosterone levels fall, but we have identified a few things.


Countries with lots of pesticide usage have lower testosterone on average.

More discussion of that in our article.

Endocrine disruptors and hunter gatherers

Endocrine disruptors are chemicals that mess up your hormones. People in the past (when testosterone was higher) were not exposed to these chemicals.

Hunter gatherers are mostly not exposed to endocrine disruptors and we’ve collected data here showing that their testosterone is frequently much higher than ours, sometimes more than double on average. (Our article about that)

Common sources of endocrine disruptors are skin products like shampoo, moisturizer, and sunscreen. Another source is microplastic dust from polyester clothes, carpets, and furniture.

Safer, more natural shampoo is available here: Baby Shampoo & Body Wash by Dapple Baby.

Polyester fabric can be replaced with natural fabric like 100% cotton or 100% wool. You can put a 100% cotton sheet over top of polyester fabric furniture to prevent the polyester from putting microplastic dust into the air in your house.

Clothes, and especially underwear, ought to be cotton or wool. Beware of blends that claim to be cotton or wool but are actually partly polyester or another synthetic fabric. It’s kind of hard to find truly 100% cotton or 100% wool underwear, so we saved you the trouble:

100% merino wool boxers:

And some 100% cotton boxers:

What’s the bottom line?

In conclusion, eating natural food (ideally organic), minimizing the use of skin products that have anything weird in them, and minimizing microplastic dust from synthetic fabrics are all valuable things you can do to keep your hormones healthy (once you have made sure you are sleeping well and getting healthy and lean in general). Clever tricks like eating onions really aren’t something you have to focus on.

Good luck!