The honest answer is that we don't
actually know why testosterone levels
stopped declining and started going back
up because obesity rose from roughly 35%
to 39% moving exactly the wrong
direction to explain higher
testosterone. Population level analyses
give very little clarity to your
specific situation. How do you maximize
your own natural testosterone levels?
Don't worry about sex and jerking off.
If you're doing all that and your test
levels are still low, you might want to
consider TRT, but the question is how
and when.
>> [music]
>> Hey guys, Dr. Mike here for RP Strength.
We've heard for years that our
testosterone levels are falling.
>> No.
>> McGainz.
And it's kind of scary.
But
recent research says they're rising.
Like, seriously, what is going on here?
Let's dig in. Here's the popular story.
It's that modern men have dramatically
less testosterone than their fathers or
grandfathers did.
Depending on the podcast microphone
involved, really, cuz you got a lot of
interesting takes here, testosterone has
supposedly fallen by somewhere between
30 and 50%
or approximately one entire real adult
Viking per generation. Scott, aren't
Viking men like the ultimate
testosterone exhibit?
>> Yeah, for sure.
>> How do Vikings in your mind compare to
pirates and lumberjacks?
>> I mean, Vikings are top because they
have like the beards and the long hair
and stuff and they pillage
>> Yes.
>> I guess pirates pillage, but not to the
same degree.
>> No. They do low-key pillaging.
>> And they have like peg legs and
eye patches. That's not
>> That's going to lower your test levels
for sure.
And lumberjacks are
just good-hearted people, Scott, just
doing God's work.
>> Doing wholesome
>> Wholesome work.
>> [sighs and gasps]
>> So, the exact headline here is shaky,
but this headline of test levels are
falling did grow from several legitimate
secular trend findings rather than from
like pure internet vapor which a lot of
other myths come exactly from pure
internet vapor.
Now,
there have been also
declines in testosterone that could be
attributed to other factors that can be
corrected for in these analyses. For
example, aging.
Testosterone tends to decline as an
individual man ages.
But a secular decline adjusts for that.
That means a 40-year-old tested in 2005
has less testosterone than a comparable
40-year-old tested in 1990.
Age adjustment attempts to separate the
population got older from same-age men
now have lower levels, which is a very
different claim.
One big study, the Massachusetts Male
Aging Study, produced one of the
strongest early signals. Researchers in
this study analyzed 1,532
men from the Boston area. Hey, Boston.
Whoa. Cat. Hey, Scott, my cat's got low
testosterone. I don't know what I'm
doing.
I don't know what that was.
Matt Damon, help.
This gave us 2,769
observations across the late 1980s, the
1990s, and even through the early 2000s.
What they found is that a substantial
population-level decline that was
greater than the decline expected from
aging alone. So, something is definitely
was definitely going on here.
That decline actually survived a bunch
of other adjustments for several obvious
suspects.
It corrected for changes in obesity,
which is huge,
changes in smoking, medication use, and
general health. They didn't fully
explain the Massachusetts trend.
Now,
they explain a huge amount of the
variance that other studies site. So,
the Massachusetts study decline was much
smaller than just raw data. They
explained some.
So, they didn't prove that these factors
had zero causal role, but it means the
finding could not simply be erased by
saying, "Oh, it's just BMI."
>> [gasps]
>> It seems like some real testosterone
decline was actually occurring.
Now,
you would think maybe this is only a US
trend
of testosterone going down, but a very
large Israeli healthcare dataset,
Israel's at the other end of the world,
points in exactly the same direction.
Investigators there examined
testosterone tests from over 100,000 men
between 2006 and 2019 and reported a
highly significant age-independent
decline across most age groups. Scott,
ready? Oy, my testosterone levels and I
know, wait, wait, those aren't Brooklyn
Jews, Israeli Jews. Uh let's see if I
can get my Israeli Jew going. Um eh, you
know, testosterone, it's what whatever,
that's life, no?
I would say other things, but um but the
Israeli Jews I don't with.
I'll just shut up.
All jokes aside,
the strongest version of the decline
claim seems actually credible. So, we're
not here to say that the decline never
occurred. Several populations,
different age groups, and different
periods show lower testosterone in men
tested later,
even after age and obesity adjustment,
which take care of most of the
difference, but not all.
The effect may in fact be biologically
meaningful, and everyone merely got
older and fatter is not the complete
explanation. Now, as is often true about
the internet, the number of claims as to
why our test levels have fallen is
enormous.
Here are some that have serious evidence
behind them and some that are way
shakier.
For explaining the overall decline over
time, obesity is probably the biggest
proven contributor.
More body fat lowers total testosterone,
while severe obesity also suppresses
free testosterone, which is the stuff
doing stuff to your body.
In a recent NHANES data set, obesity was
linked to about 2.7 times the odds of
having a testosterone below the minimum
cutoff of 300 ng per deciliter.
Guys, that is a huge deal. And last I
checked, obesity from 1970 to 2010 or
2020 has massively increased, so this
tracks.
Next, insulin resistance, diabetes, and
chronic illness also matter.
Impaired fasting glucose raised the odds
of low testosterone by about 55%, while
diabetes range glucose nearly tripled
them.
The relationship also runs both ways,
since low testosterone may worsen body
composition and make metabolic health
worse, which lowers testosterone levels,
and the cycle continues. That's really
gnarly.
And all of these, insulin resistance,
diabetic outcomes, glucose handling, and
testosterone itself are made worse still
via obesity. So, first of all, obesity
is a big deal here, but even without
obesity, insulin resistance and other
things can interfere with testosterone
levels. And this is a massive epidemic
in the United States for a huge fraction
of people. Diet composition is often
proposed.
Might have small effect, but no food or
food group is the endocrine assassin all
by itself. Some small studies find
slightly lower testosterone on very
low-fat diets, but almost no Americans
eat very low-fat diets. While newer
analyses, in fact, find very little
difference.
Here's a myth we're just going to kibosh
right now. Soy and related isoflavones
do not appear to lower male
testosterone. This has been studied to
the ground. I do give you permission to
hate hippies anyway. Hippies, I'm
kidding.
Just kidding, guys. Easy. Pass the
blunt. Or maybe not. Or maybe not.
Because cannabis
may lower testosterone. May lower
testosterone, especially in extreme use.
And it's tough to see if it's the
cannabis itself or the degradation in
sleep quality that cannabis extreme use
causes. Other factors can be in play as
well. Pollution, heat, alcohol, stress,
depression, and modern work patterns may
each play a role in reducing test
levels.
Some of these affect sperm more clearly
than testosterone, and many effects
appear small or strongest only at very
heavy exposures to these things.
None of these are major players to
explain the trend, unfortunately.
A lot of people have talked about
endocrine-disrupting chemicals.
Now, that's plausible, but it's not a
solved case.
Phthalates, BPA,
PFAS, and similar compounds can affect
reproductive biology, and some are
associated with low testosterone, but
the human evidence is observational and
very messy. So, plastics caused
everything is a far too confident of a
take, though it could be true in part.
And lastly,
the entertaining suspects for
testosterone reduction are mostly weaker
or unsubstantiated. Porn, masturbation,
ejaculation, tight underwear. Scott, I
found out that there is a hypothesis
that very tight underwear reduces
testosterone levels. Can you believe
that?
>> I just thought it was sperm count.
>> Yeah. Here's another one, it gets
weirder. Hot showers.
>> Oh, jeez.
>> Right? Phones in your pockets, soy
burgers, and insufficient lumberjacking,
which is otherwise a serious national
problem, I guess, along with
insufficient pirating and insufficient
oil rigging, have all been accused.
Sexual activity can briefly shift
hormones, but there's no good evidence
that masturbation caused decades of
falling testosterone. Scott, I'm back in
the game, baby.
>> Hey.
>> [laughter]
>> All right. So, test levels are falling,
and it's mostly obesity, but a combo of
other smaller factors
that might matter even if you're not
obese. But wait,
are they still falling the testosterone
levels? Because our data set that we
just talked about ends in the 2010s.
Here's the wrinkle.
A just published study in 2026
analyzed over 10,000 American men across
nationally representative NHANES cycles
from 2011 to 2016 and from 2021 to 2023,
much more recent. And remember,
testosterone has been sort of falling
for much of the time before this.
Testosterone deficiency in these
analyses was defined as total
testosterone below 300 ng/dL.
Reported testosterone users were
excluded and measurements used CDC
standardized LC-MS/MS methods, which is
really good cuz we have method
standardization. We can be more
confident.
Across the entire sample, 25.7% tested
below 300.
That doesn't mean a quarter of the US
male population, or at least as sampled,
has clinical hypogonadism, which also
requires symptoms and repeat morning
testing.
It does mean that a lot of folks
have very low testosterone levels and
would probably benefit in my experience
and my estimate from testosterone
replacement therapy or at least thinking
about it.
That being said, some folks coast on
300, some folks are miserable on 400.
But from the beginning of the data set
to the end, roughly from 2011 to 2023,
age standardized raw testosterone levels
below 300 ng/dL,
how many for what fraction of the testes
had below 300 ng/dL test, fell from
29.3%
to 22.4%.
Obesity, impaired glucose, diabetes
range glucose, and 8 plus sedentary
hours all predicted low testosterone as
expected, but while most of these went
up during this time.
Test levels also went up.
>> [snorts]
>> Or rather, the fraction of people under
the test low cutoff declined a ton. I
mean, 29.3% to 22.4% in a massive
thousands of people sample is a big
deal.
In fact, that trend of increasing
testosterone levels, or rather less of a
decrease,
that trend survived survey waiting, age
adjustment, standardized prevalence
estimates, and sex hormone binding
globulin related sensitivity analysis.
During that time, obesity rose from
35.1%
to 38.9%. Damn, Scott, the 20 teens were
a time for obesity, huh? Holy crap.
>> [gasps]
>> Low testosterone during that time
declined, the opposite of what obesity
alone would predict.
Now, the paper mainly measured the
fraction below 300, not population mean
testosterone.
The bottom of the distribution could
improve without every percentile rising
equally. And a recent rebound does not
erase earlier declines.
Testosterone could have fallen for
decades and then partially recovered.
Both findings can be true.
But even if partial recovery is real,
why are test levels going back up? We
have a few hypotheses.
Extreme sedentary time
fell from roughly 40% to 36%, which
could have provided some upward people
are a little bit less inactive, a bit
more active, I guess.
Access to regular health care improved
slightly, potentially help identify and
treat obesity, diabetes, sleep apnea,
and medication-related problems, but
those are all true except for the
obesity part, because obesity rose from
roughly 35% to 39%, moving exactly the
wrong direction to explain higher
testosterone.
>> [gasps]
>> Diabetes range fasting glucose barely
changed, despite being associated with
nearly triple the odds of low
testosterone. Smoking declined, but
here's something interesting about
smoking.
Smokers often show higher total
testosterone or sex hormone-binding
globulin. Obviously, smoking remains
spectacularly unhealthy and interferes
with muscle growth, too.
It also reduces the pumps that you're
getting from training, which is really
terrible, but it does keep your test
levels high on paper, and all the cool
celebrities do it, which is why I smoke
three packs a day religiously, to be
completely honest.
Age can't explain the increase because
it survived age standardization.
Now, unreported testosterone
supplementation, steroids, hCG use,
clomiphene, or enclomiphene could have
inflated the results.
Although, excluding values above 1,000
ng/dL barely changed the results, and
very few people actually get these
treatments.
To complicate matters,
COVID created a large sampling gap and
may have changed who participated, how
they lived, and how healthy they were.
So, the honest answer is that we don't
actually know why testosterone levels
stopped declining and started going back
up.
I mean, at least I don't. Who the hell
is we? I'm having a schizophrenic
episode again.
The result probably reflects some
mixture of real recovery,
maybe some health care changes,
sampling, hormone use, testing
conditions, and assay differences.
Ah.
Not very compelling.
But for you and your test levels, it
doesn't have to be, and here's why.
It's because population analyses are
very, very limited and always were.
Population level analyses give very
little clarity to your specific
situation.
NHANES tested different men in each
cycle.
It did not follow the same people from
2011 to 2023.
>> [snorts]
>> Survey weighting improved
representation, but cannot perfectly
correct for participation, survival,
fasting compliance, or unmeasured
subgroup changes.
Population averages can shift with age,
obesity, health, medication use,
smoking, alcohol, income, sleep, diet,
exercise, and work patterns.
Morning ver- versus afternoon testing,
meals, sleep loss, illness, dieting, and
hard training can all change individual
results.
Also, the 300 cutoff creates a bit of an
artificial cliff. A man at 299 and
another one at 301 are basically in the
same exact situation, but the cutoff
splits them into you're totally fine and
you need help.
Sexual activity may cause brief hormonal
fluctuations, but masturbation frequency
is unlikely to explain a national
multi-decade trend. And also the
reversal of that trend. Endocrine
disrupting chemicals may matter, but
human studies struggle with chemical
mixtures, confounding, exposure
measurement, and reverse causality.
Some of the best insights onto this have
proven to be kind of worthless.
The biggest deal here is the double
inference problem. We barely know why
the average changed. And the average
still cannot diagnose you.
Symptoms, health, medications, fertility
goals, and repeat testing matter far
more for your levels.
But before considering all of that,
there are massive things you can do to
boost your test levels personally.
What society is doing, how do you
maximize your own natural testosterone
levels? Here are the big hitters.
First, get consistent high-quality
sleep, usually around 7 to 9 hours, and
treat serious sleep disorders like apnea
ASAP.
Next, lose excess body fat when obesity
is present. Substantial weight loss is
probably the most reliable, broadly
applicable natural intervention to
boosting your testosterone. If you're
over as a male about 15% body fat,
losing fat is very likely to help.
Next, avoid prolonged, severe dieting or
unsustainably low body fat, especially
when you're already lean.
Eat enough calories, protein, essential
fats, fruits, vegetables, and
micronutrients to avoid deficiency.
Eating a healthy, high-protein diet is a
big deal.
If you eat too little protein,
or you eat too little carbs, or you eat
too little fats,
or you're eating too few nutritious
foods like veggies and fruits, your test
levels won't be ideal. Cutting out
entire food groups is almost always bad
for test levels.
Another one is to avoid periods of
prolonged psychological stress. It's
easier said than done, but it's a real
thing.
If you're training, that's great, but
your testosterone levels won't actually
change much. It is a myth that lifting
hard makes your testosterone levels
consistently higher.
But, way too much training, too much
volume, too much frequency, and
accumulating too much duration of hard
training without backing off can
definitely lower your test levels.
So, if you have a week of crap recovery
and all else is good, deload, or just
take the week off.
Don't worry about sex and jerking off.
Have whatever healthy amount of sex or
masturbation that suits you. Abstinence
rituals, while we're at it, and most
commercial test boosters, while we're at
it, have little meaningful evidence for
actually changing testosterone levels.
And when you're testing your test levels
correctly, two separate fasting mornings
after normal sleep, while healthy and
not deep into contest prep, is the way
to go. And when you have your test
levels checked, also check sex hormone
binding globulin, free testosterone,
ideally also estradiol, when
appropriate.
If you're doing all that and your test
levels are still low, you might want to
consider TRT, but the question is how
and when.
You might be a candidate for TRT if your
test levels are low, but before you go
shooting every test vial under the sun
into your urethra, which is how you
administer TRT, that's a joke,
let's talk about some signs your test
might be low.
Reduced sex drive.
Fewer morning erections. Infertility.
Hot flashes. Testicular shrinkage. Body
hair loss, which is I wish I've
exhibited at some point. That never
happened. Anemia, which means low iron.
And declining bone density are
relatively informative signs of serious
testosterone deficiencies.
Other signs can include fatigue, brain
fog, low mood, poor sleep, fat gain, and
weak gym progress.
A lot of these are pretty non-specific
and have a bunch of different causes,
but if they all occur together and your
testosterone levels are low, you know
you're on to something.
Another one is a lower desire to train.
Not a bit lower, like a lot lower. Like
you used to be pumped going to the gym
and now you're just like, "Uh." And
workouts are really tough to get through
motivationally.
If you have these signs, especially if
you have a lot of them all at the same
time, go to your doctor and ask to be
examined for your testosterone levels.
It's a super cheap test, so you might as
well throw in FSH, LH, estrogen, free
testosterone, SHBG and them all as well.
If that comes back on the lower end and
you have a bunch of those symptoms, now
that's a conversation about potential
TRT to have with your doctor. With your
doctor. Don't free will this stuff,
guys.
It often ends really poorly that way.
If your test levels are normal, but the
symptoms all match lower testosterone,
that's also a conversation. Because
remember from earlier, what's normal for
some is low for others.
So you could actually still be a
candidate for TRT even if you have
relatively normal levels, but you
experience all the symptoms.
Now, if and when you get on TRT,
testosterone replacement therapy, every
few months, monitoring of values is
critical. Because you're going to want
your doctor to help you increase and
decrease the amount you're prescribed,
so you can see how your measured test
levels change and measure health
markers, as well as like how are things
feeling and how are things doing in the
gym.
Your ideal test levels are when the
values on measurement aren't insanely
off the charts, right? They're in a good
high average range.
Your health markers like blood pressure,
cholesterol, liver values, and so on
are their best. And your mood, sexual
stuff, and lifting are also at their
best. It's going to take some time to
get there to that ideal range for you,
but you can. And then you don't have to
worry about who has rising or declining
testosterone levels in the population
because you will be swimming in gains
and in female ejaculate ideally.
All right, guys. That's the summary.
Yes,
>> [music]
>> test levels were going down for a while.
Yes, they stopped going down. No, we
have no idea why, but your own test
levels are very much in your own hands.
Just like the organs that produce them.
Hey, am I right? All righty. [music]
See you guys next time.
>> [music]