Discussion summary
Men's average testosterone levels have halved over the last 50 years, with potential influences including lifestyle, diet, and environmental factors. Experts debate whether social changes or biological factors are more responsible.
What the discussion says
- Some believe lifestyle and diet are primary causes.
- Others argue social and cultural shifts impact testosterone levels.
- Skeptics question the validity of rapid biological changes.
“The decline may be linked to lifestyle and environmental factors.”
“Biology doesn't change that quickly; claims should be scrutinized.”
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- Hacker News
- soy, cortisol, plastics, birth control remnants in the water and food supply, adipose tissue accelerating conversion of testosterone into estradiol, and compounds acting to keep free testosterone levels low and bound testosterone levels high. combine that with sedentary lifestyle, the demonization of red meat healthy fats and cholesterols (cholesterol is extremely close to testosterone and converts easily) and the systematic promotion of a plant based heavily processed diet can easily lead to this. the traditional diets of slaves and serfs was low meat & high grain to keep them weaker dumber and shorter in general. the lowered testosterone and will to fight and resist oppression was also a "feature, not a bug" as my llm likes to say every chance it gets.
the industrial revolution has been a disaster for the human race.
by snootypoot - “Obesity and diabetes could easily account for all of this,”
Wither Ozempic? I've seen several friends and family members use it to great effect and thought it might sweep the nation. But I imagine most of the same barriers that keep people from eating better or moving more are also in play when trying to engage with any new habit.
by standardUser - Also, aging populations.
There's a larger proportion of older males in the population now than there has been in most of history. Testosterone decreases as we age. The average is across _all_ males, even those outside of reproductive years. I assume if we controlled for outliers, that the results would be fairly comparable across time.
by smarm52 - Per the article, they did at least try to control for age (it'd be a completely uninteresting result if they hadn't). The big concern is that they did _not_ control for obesity or diabetes.by rsynnott
- Could this be a possible factor in the reduction in violent crime (at least in some countries)?by ThinkingGuy
- That is extremely closely linked to lead, especially the ban on leaded gasolineby lynguist
- I wonder how this correlates to Prostate Cancer. From what I heard, high testosterone can be one of the causes of Prostate Cancer. But that is over a long time.
So if levels are falling, is prostate cancer lowering a little bit ? But that will be hard to determine due to the advancement of Medical Treatment over the past 50 years.
> Rising levels of obesity and diabetes
Plastic Bottles also replaced glass starting in the early 70s too. I remember reading some type of plastic can leak estrogen into the food. So seems a lot of things happened of the past 50/60 years that will impact ones health negatively.
by jmclnx - High cortisol lowers testosterone - some adaptogens like ashwagandha modulate the HPA axis and lower cortisol release, increasing T levels
- I'm old, but I get this subjective read: of my friends and even family who had sons, they seemed smaller and less bold than we were 50 years ago.by OldSchool
- less bold? what do you mean?by ibero
- There is also correlation of the elimination of Lead Paint to violent crime. So that may need to be taken into account.
Lead Paint elimination started in the Early 70s IIRC, so the same time period :)
by jmclnx - This study is measuring adult men’s testosterone levels, not children’s. Boys don’t even produce that much testosterone until puberty.
This study has more to say in comparing adult men today to their grandfathers.
by janalsncm - I really wonder, what is “normal”?
One class of doctors thinks roughly 250 is enough for a middle aged guy - anything over shouldn’t be medically treated. Of course, the “men’s clinics” don’t rest until it’s over 1000...
With the standard range so wide (even after age adjustment), why isn’t it measured annually, like the CBC and others?
Sure, it’s easy to point at obesity, but statistical ranges completely fail the individual.
by BobbyTables2 - The effect is so variable that the reference range is nigh meaningless. Some people feel great at 300ng/dL. Some people experience genuine low-T symptoms at 650 that are fixed by bumping it to 1000. Some people are naturally over 1000 and have otherwise average hormonal profile (hair growth, muscle growth).
Also, the reference range is defined by an age span that is too wide to be useful, something like 21-59. The reference range is completely meaningless for a 25 year old man. Also the level varies drastically throughout days and weeks, so that one test is not a useful indicator of anything unless it's off the charts.
Basically, if you have low-T symptoms you should probably just get on T regardless of what number the test says. Find a doctor who agrees.
by eudamoniac - There are wide ranges but it's more about how you feel personally and what you've noticed over time. Some men have below average T but feel great and build serious muscle anyway.
The two sigma range is something like 300-900 with std being 150 and median 600. This is for what is labeled as healthy 18-39 men. It doesn't include obese men.
If you want to take something away from it, just get yourself measured a few times over a few years. Then later if you have issues that relate to low T or whatever you can flag it with your doctor. In my case, it was super important because I found out I am in the top 0.01% of (healthy) total T producers. If I had "low T" type symptoms and went to my doctor without that information - they'd be like, "no, your T is amazing actually."
Everyone has a different baseline. I only wish I started measuring before I was in my mid-30s because I feel my levels before were even more ridiculous.
by bradlys - “The solution that’s being promoted is that we give you testosterone,” he said. “But if you give a man testosterone, you switch off his sperm production. I’ve seen that in the clinic.”
Interesting…
by xvxvx - Are you being sarcastic? That has been widely known by steroid users for decades, that's why many of them supplements with hCG in an attempt to preserve their natural production.by Zealotux
- It's becoming clear that it's not permanent. Discontinuing exogenous testosterone will lead to restarting your own body's production - it just takes a bit, and isn't fun to deal with.by Ancapistani
- As explained by https://www.nytimes.com/2026/05/12/magazine/testosterone-mas..., "Supplementing with testosterone sends the message to the brain that testosterone is in oversupply, shutting down the testicles’ production of testosterone and sperm... The hormone is so incredibly effective at decreasing sperm counts that it is being tested as a possible male contraceptive."by joshkel
- I don’t understand why obesity seemingly gets tossed aside when this subject comes up.
It’s the one problem you can see in plain sight at any gathering of people.
by BoggleOhYeah - Because it's too obvious. There needs to be some hidden, world encompassing conspiracy, so that people feel superior when they are one of the few enlightened ones that see through the matrix and start drinking raw milk to live like our testosterone pumped ancestors.
- Because especially in this forum, obesity literally does not exist and if it does is never the person's fault but rather big food producing addictive meals / not walkable cities / exercise is bad for your joints / et cetera ...by thefz
- That's literally the main point of the article, the stand-first: "Exclusive: Researchers warn of ‘major crisis in male reproductive health’ partly driven by obesity and diabetes"by Zealotux
- > Obesity was also not controlled for, which is known to be strongly correlated with low testosterone.by idleplant
- Really makes the study completely pointless when the last 50 years has also seen the rise of the global obesity epidemic.by tokai
- In the past decade, research suggests that testosterone levels have actually gone up[1].
[1]https://www.cremieux.xyz/p/why-are-testosterone-levels-risin...
by idleplant - Testosterone is directly causally inverse to bodyfat in men (once above some very low baseline)
Fat directly converts testosterone to Estrogen via a process called aromatization.
Personally my Testosterone close to doubled when going from 25% bodyfat to 13%. I get blood tests regularly and can see the levels fluctuate pretty closely with fat levels
by adam_arthur - Before the reactions to the headline get too out of hand, the article says the study couldn’t rule out that obesity and diabetes might drive this change. Occam’s Razor leads me to lean on this more than any other exotic explanation.
Of course, PFAS and microplastics aren’t great for sperm health, but neither were leaded gasoline and DDT before they were curtailed.
by janalsncm - Which means, given GLP-1s, we should see a reversal in the next few years.
Random aside: is there a correlation between GLP-1 and vaccine acceptance? As in, given enough time, would one expect to see an obese, diseased, low-T population concentrating in on itself?
- I’m pretty sure other experts are also saying that it’s due to a different way of measuring levels.by unparagoned