Several studies have asked this, with differing results. But some find that testosterone does appear to vary through the year to a moderate degree. It usually peaks around the Autumn, then drops through the winter to a low in the Spring.
Paris 1975: five healthy medical students and biochemists living in Paris age 26-32. “The peak of plasma testosterone was in November (909 ± 42.7 ng/dl) and the trough was in May (640 ±51.1 ng/dl)”) (source)
1974-1975 in Nijmegen, The Netherlands: 15 healthy men age 24-45. Testosterone averaged 666 ng/dl in April 1974, 744 in July, 762 in October, 665 in January 1975, and 631 in April 1975. (source)
That was the average, but there was a lot of individual variation. Some men peaked in July and some peaked in October. One man looked like this: April: 781 ng/dl, July: 1084, October: 1144, January: 586, April 778. That guy didn’t like January much! However, most of them did not change as much as that. Maybe that guy had very low Vitamin D or something.
Boston, Massachusets in the USA in the 2000’s – Among 30-79 year old men, testosterone rose until July, reaching 470 ng/dl, and then began dropping to a low in December of 385 ng/dl (source) The study didn’t find the differences to be significant however.
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.
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.
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:
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.
These moisturizers have no endocrine disruptor chemicals like phthalates or PFAS. There should be nothing but natural ingredients in a moisturizer without endocrine disruptors. Of course, the best moisturizer is the one that you enjoy and get the best results from. You should like the smell and the feel of it, and it should work well for you.
We like moisturizers that are all natural. We don’t think there should be any ingredients that sound like a chemistry experiment, even if they are mostly safe. To really protect the hormones, we think it’s best to stay 100% natural. That’s why our top picks contain nothing but beef tallow, honey, shea butter, or essential oils. These are all natural products quite close to their natural state.
Xenoestrogens on my skin? No thank you!
The synthetic, commercial products you might see at the store contain a variety of weird chemicals. Many of the chemicals are endocrine disruptors, specifically they are artificially estrogenic, which is why some of them are also known as xenoestrogens.
Phthalates are common in most moisturizers since they have an ability to moisturize the skin. But it is not worth it! Phthalates are xenoestrogens, meaning that they will increase risk of breast cancer and hormonal mood swings. Our recommendations are free of phthalates.
Should you really put tallow on skin?
Yes! Reviewers report great results when they use the tallow and honey balm. They say it feels great, with no icky mess at all. And they report seriously good results from the balm. Skin clears up, and dry skin goes away and stays away.
Tallow and honey both nourish the skin. They contain powerful natural compounds that your skin craves.
Tallow and honey together make the best moisturizer without endocrine disruptors
We like the tallow and honey balm best of all. There is absolutely nothing unnaturally hormone-damaging in it. It has no weird chemicals that might cause mysterious bad health effects. Tallow and honey are both near-superfoods full of healing and rejuvenating parts. Honey has been known for centuries to facilitate healing.
Shea butter is a good moisturizer too!
Shea butter is another good moisturizer without xenoestrogens. If you are looking for a vegan option, you should go with this one, since it comes from a tree.
It’s important to use sunscreen without endocrine disruptors. These sunscreen products are free of harmful chemicals like this. Endocrine disruptors are chemicals that damage your hormone levels. Endocrine disruptors are associated with breast cancer. Unfortunately, many sunscreens have these chemicals.
There are two ways to block UV rays from damaging your skin. One is a chemical sunscreen – these are invisible on your skin. The other way is a physical sunscreen, which literally coats your skin so the sun is reflected off instead of reaching your skin. These are always a layer of visible color on top of your skin, because they have to physically block the sun’s rays. Unfortunately, there isn’t currently any chemical sunscreen without endocrine disruptors. They’re all physical sunscreens. Hopefully in the future someone will invent one, perhaps using certain promising herbal ingredients. (Like these)
Common endocrine disruptors in sunscreen to avoid
Oxybenzone (also known as Benzophenone-3), PABA, and homosalate are all common endocrine disruptors found in sunscreens, but not in the ones we listed. Since these chemicals have artificial estrogenic activity, they are called “xenoestrogens.” (source) Using sunscreen without xenoestrogens is imperative if you want to lower risk of breast cancer, or keep testosterone levels where they naturally should be. You should definitely use one of the xenoestrogen-free sunblocks listed here instead of a hormone-damaging one from the store.
What about olive oil or raspberry oil for sunscreen?
And raspberry oil may have some minor ability to block the sun as well.
Sunscreen that doesn’t lower testosterone
One of the big effects of endocrine disruptor chemicals like those found in some sunscreens is to lower testosterone. Since there is something of a low testosterone plague going on, probably due to the various chemicals in the environment, it is pretty important to be careful about only using a sunscreen without endocrine disruptors.
Other chemicals to avoid
We also want to avoid parabens and other strange chemicals in sunscreen. The ones we recommend are free of these things.
More things you can do to avoid sunburn
Simply staying out of the sun when your skin is vulnerable to sunburn is the best thing you can do. Always bring a coverup or have access to shade.
Only get as much sun as your skin can handle. While it’s true that the sun is good for you, it is still very bad for you to get sunburned. It is radiation damaging your skin and you don’t want this!
Apparently, Vitamin C, avoiding seed oils in your diet, and Vitamin E will all help you be a bit more sunburn resistant, but you shouldn’t rely on this at all.
Timing your sun exposure to avoid sunburn
If you get sun before 10am and after 4pm (or pre 11am & post 5pm during daylight savings time) then the sun doesn’t really contain as much UV light that burns you. You can get lots and lots of this sunlight and experience the healthy effects of bright and red wavelength light on you, without worrying so much about being burnt. Then you can get maybe 15 minutes of full body UV sunlight during the middle of the day to get your Vitamin D.
In Dhaka, Bangladesh in 2015, testosterone was 423 ng/dl.
Is Bangladesh’s average testosterone level lower than the testosterone levels in other places in the world?
Much of the world is having an unusual, unexplained fall in testosterone since about 1980, at least. Bangladesh is unfortunately not spared from this problem. The low levels of testosterone here are pretty similar to those found after the rest of the world’s decrease. Unfortunately we don’t have historical data from Bangladesh to see what testosterone levels used to be here, but the levels would likely have been a lot higher and healthier, since we have data showing other countries in South Asia with higher testosterone in the past than what they have today.
(Note: Since testosterone levels change with age, we age adjust the data to make the data reflect a whole population of all ages and thus be comparable to data from other countries, also age adjusted by us to reflect their whole populations)
In the land of Belgium around 2008, the average man’s testosterone was 561 ng/dl.
Is testosterone in Belgium lower than the testosterone levels in other places in the world?
Testosterone is decreasing in many places around the world. (We think that the blame can be placed on chemicals called endocrine disruptors and seed oil in the diet) Belgium has had some decrease in testosterone like many other places. However, they’ve still maintained pretty good testosterone levels, and their current level isn’t as bad as most other places. So that’s good! If you’d like to know more, please see the article on this site about how testosterone has fallen.
All our data on Belgium
We got the 561 number for Belgium by averaging the last two most recent datapoints. You can see all the raw data in our spreadsheet here.
What’s the average testosterone level in the other countries?
Testosterone is decreasing in many places around the world. (In our opinion it’s chemicals called endocrine disruptors and seed oil in the diet) Unfortunately, this is happening in Brazil too, which is having a decrease in testosterone like most other countries, and is now quite low. We think it might be Brazil’s heavy use of pesticides that’s doing it. If you’d like to know more, you can check out our article on how and why testosterone has fallen over the years.
In Ontario, Canada in the year 2011, testosterone was 402 ng/dl. Unfortunately we don’t have more data that is recent enough to use.
Is Canada going through the decrease of testosterone like the rest of the world is?
Canada has had its testosterone levels decrease way too much, but this is the norm for the other parts of the world sadly. In most places in the world, testosterone has been dropping for a good five decades. There are only a few places where they are still experiencing high testosterone. See our other articles to learn more.