August 5, 2026 • 14 mins
OK, that's a trick question. Aspirin goes everywhere in your body -- and wherever it goes, it works by preventing processes that amp up pain signals, encourage inflammation, cause fever, and more. Learn about the history and workings of aspirin (aka acetylsalicylic acid) in this episode of BrainStuff, based on this article: https://health.howstuffworks.com/medicine/medication/aspirin.htm
See omnystudio.com/listener for privacy information.
Listen
Watch
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Lauren Bogelbaum. Here, we all experience some aches and pains
as we move through the world in are weird and
wonderful human bodies. Sometimes we take something to ease that pain,
and on a global level, that something is most often
(00:24):
aspirin or pacetylsalicylic acid. About forty thousand metric tons of
aspirin is produced and consumed every year. That's over one
hundred billion tablets. It's not only used for headaches. It
can ease fevers and inflammation too, and millions of people
take aspirin to help prevent heart attacks. There are good
(00:47):
reasons a doctor might say, take to aspirin and call
me in the morning. So today let's talk about how
aspirin works and how it doesn't, and how some good
science helped it become the most common drug in the world.
As far back as three thousand BCE or thereabouts, ancient
Mesopotamian physicians were writing about the use of parts of
(01:10):
the willow tree to treat pain and inflammation. The ancient Chinese, Egyptians, Greeks,
and Romans all recorded their use of willow extracts but
it wasn't until the eighteen hundreds ce after the birth
of the field of chemistry, that we started to understand
why willow can work for these purposes. In the eighteen twenties,
(01:32):
a few different chemical detectives, including Friedrich Buchner and Henri LaRue,
isolated an extract of willow that was very bitter and
very potent for use in treatment of things like rheumatism.
They called it salasin, after a Latin word for willows salix.
Over the next couple of decades, other chemists figured out
(01:53):
the molecular structure of salacin and how it can be
oxidized to produce the related compound salcilic acid, and then
how to synthesize salasilic acid at a large scale in labs.
In the eighteen seventies, due to this discovery, the Hayden
Chemical Company in Germany became the first ever industrial manufacturer
(02:15):
of any drug, and the commercial market for salasylic acid
boomed for use in treating pain and swelling in diseases
like arthritis and fever. In illnesses like the flu. The
problem with salasilic acid is that it can upset the
user's stomach fairly badly and even cause bleeding in the
digestive tract at high doses, but researchers were working on
(02:37):
it enter one of Hayden's national rivals, Bayer in Company.
In the eighteen nineties. Chemists at Beayer reasoned that perhaps
salicilic acid was so hard on the stomach because it's
an acid. They knew from research back in the eighteen
fifties in France that you can use chemical reactions to
(02:57):
cover up one of the acidic parts of seala silic
acid with an acetyl group, converting it to acetyl salicilic acid.
They figured out how to synthesize pure medical grade aceetyl
salicilic acid, and after a couple of years of testing,
Beyar patented this effective and easier on the stomach medication
(03:18):
under the trade name aspirin in eighteen ninety nine. They
got the name by combining a for a setyl with
a word derived from spyriea, which is the genus name
for metal sweets, which are other plants that you can
get salasin from. Today, the name aspirin has been role
generic in a number of countries. There's actually a bit
(03:40):
of a debate now about who at Bayer was responsible
for synthesizing this compound. For decades, corporate lore said it
was a junior chemist by the name of Felix Hoffmann,
whose father had arthritis, so he was motivated to help
ease his side effects from taking salicilic acid. But one
hundred years after aspirn came out, at the turn of
(04:02):
the twenty first century, credible evidence arose that Hoffmann's boss,
one Arthur Eisngrun, was more responsible, but because Eisngrune was Jewish,
his involvement was downplayed. With the rise of the Nazi regime,
It's a mystery of history. Another long running mystery that
has since been solved is how aspirin works in the body.
(04:25):
We didn't know for sure until the nineteen seventies, when
a team of pharmacologists and biochemists came up with proof,
for which they were rewarded the Nobel Prize in Medicine
in nineteen eighty two. It took humanity all of these
millennia to figure it out, partially because pain is complicated
like no one is totally sure how it works, and
(04:47):
the more we learn, the more questions seem to arise. Okay,
like all other sensory experiences. Pain exists only because your
brain says it does, your body's way of telling you
that something has gone wrong that needs your attention. Let's say,
for example, that you hit your thumb with the hammer
(05:08):
instead of the nail you're aiming for. Please don't try
this at home. Now. Your thumb has nerve endings in it.
These are little detectors in your joints and skin that
feel things like heat, vibration, and everything from featherlight touch
to the big crushing shock of being hit with the hammer.
(05:29):
There are different receptors for each of these types of sensations. Also,
when you hit your thumb and damage that tissue, nearby
cells will release some chemicals that make your nerve endings
register the crushing shock more strongly, like turning up the volume.
Some of those chemicals are ones called prostaglandins. So very basically,
(05:52):
you smash your thumb and the nerve endings involved send
now strong signals up through your nervous system and into
your brain, which which decides that these signals mean hey,
that hurts. The pain you experience is useful information because
it tells you that your thumb is damaged and that
you should put the hammer down and be careful with
(06:12):
the thumb until it's healed. Prostaglandins contribute only a portion
of the total pain signal, but it's an important portion,
and prostaglandins also help cause the site of the injury
to swell up. This bathes the injured tissue in blood
and helps rush immune system resources into protect it and
(06:33):
start the healing process. Basically, it's a good system, but
a few problems can arise. First Off, pain is not
a neutral feeling. It's emotionally upsetting, so once you've registered
your bodily damage, having that pain signal continue isn't fun
or even particularly useful. Secondly, something's hurt without there being
(06:59):
a hammer or or open flame, or some other source
of damage that you can avoid. You might get a
headache because your scalp and neck muscles are contracted from stress,
or because a blood vessel in your brain has a spasm. Thirdly,
as we've talked about before on the show, autoimmune conditions
like arthritis or psoriasis can cause your immune system to
(07:21):
turn on healthy tissue, causing too much inflammation, which itself
can be painful and even damaging. These processes appear to
involve prostaglandins as well. Aspirin helps with these problems by
stopping your tissue from releasing prostaglandins by preventing your cells
from making them. Okay, cells working in damaged tissues produce
(07:46):
prostaglandins using an enzyme called cyclooxygenase two, or COX two.
COX two can be found and lots of normal tissues,
but much more of it is made in tissue that's
been hurt in some way. Aspirin, as it turns out,
sticks to COX two and won't let it do its job.
It's like sticking gum in a lock instead of a key.
(08:10):
Don't try this at home either, take my word for it.
The lock will not open with gum in it, and
COX two can't work with aspirin stuck in it. So
by taking aspirin you don't stop the problem that's causing
the pain, like the tight muscles in your scalp or
the hammer damaged finger. But it does lower the volume
(08:30):
on the pain signals going through your nerves to your
brain and will prevent some inflammation from happening. This is
not a targeted therapy. Aspirin doesn't know where to go
in your body. When you take a tablet, it dissolves
in your stomach or small intestine, and your body absorbs
it from there into your bloodstream, which carries it through
(08:50):
your entire body. Although it circulates pretty much everywhere, it
only works where there are prostaglandins being made, including the
area where it hurts. But the solution is not permanent.
As with almost all chemicals, your body has a way
of getting rid of aspirin. In this case, your liver, stomach,
and other organs convert aspirin to salicylic acid. Your liver
(09:15):
then sticks other chemicals onto the salisilic acid so that
your kidneys can filter it out of your blood and
send it out through your urine. The whole process takes
about four to six hours, so you have to take
another pill at that time if you want to keep
the effect going. This is also a good but imperfect system.
(09:37):
There are places in your body that need prostaglandins for
various reasons. For example, in your stomach, a related enzyme
COX one makes a prostaglandin that seems to keep your
stomach lining nice and thick. Aspirin prevents that too, meaning
that taking aspirin over time can cause your stomach lining
(09:57):
to get thin, allowing your digestive juices to irritate it.
This is probably the biggest reason why aspirin upsets stomachs,
not only because it's an acid, as Bayer's chemists thought.
There are other places in the body where prostaglandins have
a job. In normal tissues, such as the blood. Some
(10:18):
types of prostaglandins cause tiny particles in your blood known
as platelets, to stick together in forming blood clots. By
inhibiting prostaglandin production, aspirin slows down clot production. This can
be bad, like if you have a bloody nose or
a cut, in which cases you absolutely want a clot
(10:38):
to form, so maybe avoid taking aspirin there. But blood
clots can hurt us, as can happen in heart attacks
when clots clog the blood vessels that carry oxygen through
your hard working heart. That's why aspirin is recommended by
healthcare providers to some people looking to prevent a heart
(10:59):
attack or to recover from one. The way that aspirin
lowers fevers also has something to do with its inhibition
of prostaglandins, this time in the hypothalamus, which is a
part of the brain that helps control body temperature, among
other things. This one might be more complicated, though research
is ongoing. But okayke anything you can take in. There
(11:23):
is such thing as too much aspirin, and it can
cause some unwonted side effects like bleeding or bruising if
it prevents blood clots and upset or damage to the stomach.
A risk of these side effects increases when you take
aspirin alongside some other drugs like other painkillers, plus blood thinners,
and many antidepressants. Additionally, aspirin is not recommended for bringing
(11:47):
down the fever of kids with virus infections like the
flu or chicken pox, because aspirin is associated with a
deadly condition called rhye syndrome. In cases like those, drome
causes brain damage, so aspirin should not be given to
children and less directed by a healthcare provider for a
specific condition. But for these reasons, scientists have found other
(12:12):
chemicals related to aspirin that have some of its good
effects and lack some of its bad ones. For example, abuprofin,
sold under the brand names advil or motrin, and nepoxin
or a leave can also treat pain, swelling and fever,
but seem to have less of effect on platelets than
aspirin does. All three of these are in a class
(12:33):
called non steroidal antiinflammatory drugs because they decrease swelling, but
they're not steroids, which are the most potent antiin inflammatories
that we have. A Different class of medicines related to
aspirin includes acetaminifin or tailanol, which decreases fevers and pain
but doesn't affect inflammation or your stomach as much as
(12:54):
nonsteroidal anti inflammatories do, and all of these options are
generally safer for kids. Even with different options, asprin is
still something of a wonder drug today. More research is
being done to see if it might be able to
help with other conditions, like some forms of cancer. As always,
human bodies are complicated, so talk to a healthcare provider
(13:16):
if you have any questions. But the next time you
get out a hammer, think of those thousands of years
of willow use and maybe set aside an aspirin or two.
It's best to be prepared just in case you hit
the wrong nail. Today's episode is based on the article
(13:37):
asprin one oh one on HowStuffWorks dot com, written by
doctor Lucas Hoffman. Brain Stuff is a production of iHeartRadio
in partnership with HowStuffWorks dot com, and it's produced by
Tyler Playing. For more podcasts from my heart Radio, visit
the iHeartRadio app, Apple Podcasts, or wherever you listen to
your favorite shows.
Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Lauren Bogelbaum. Here, we all experience some aches and pains
as we move through the world in are weird and
wonderful human bodies. Sometimes we take something to ease that pain,
and on a global level, that something is most often
(00:24):
aspirin or pacetylsalicylic acid. About forty thousand metric tons of
aspirin is produced and consumed every year. That's over one
hundred billion tablets. It's not only used for headaches. It
can ease fevers and inflammation too, and millions of people
take aspirin to help prevent heart attacks. There are good
(00:47):
reasons a doctor might say, take to aspirin and call
me in the morning. So today let's talk about how
aspirin works and how it doesn't, and how some good
science helped it become the most common drug in the world.
As far back as three thousand BCE or thereabouts, ancient
Mesopotamian physicians were writing about the use of parts of
(01:10):
the willow tree to treat pain and inflammation. The ancient Chinese, Egyptians, Greeks,
and Romans all recorded their use of willow extracts but
it wasn't until the eighteen hundreds ce after the birth
of the field of chemistry, that we started to understand
why willow can work for these purposes. In the eighteen twenties,
(01:32):
a few different chemical detectives, including Friedrich Buchner and Henri LaRue,
isolated an extract of willow that was very bitter and
very potent for use in treatment of things like rheumatism.
They called it salasin, after a Latin word for willows salix.
Over the next couple of decades, other chemists figured out
(01:53):
the molecular structure of salacin and how it can be
oxidized to produce the related compound salcilic acid, and then
how to synthesize salasilic acid at a large scale in labs.
In the eighteen seventies, due to this discovery, the Hayden
Chemical Company in Germany became the first ever industrial manufacturer
(02:15):
of any drug, and the commercial market for salasylic acid
boomed for use in treating pain and swelling in diseases
like arthritis and fever. In illnesses like the flu. The
problem with salasilic acid is that it can upset the
user's stomach fairly badly and even cause bleeding in the
digestive tract at high doses, but researchers were working on
(02:37):
it enter one of Hayden's national rivals, Bayer in Company.
In the eighteen nineties. Chemists at Beayer reasoned that perhaps
salicilic acid was so hard on the stomach because it's
an acid. They knew from research back in the eighteen
fifties in France that you can use chemical reactions to
(02:57):
cover up one of the acidic parts of seala silic
acid with an acetyl group, converting it to acetyl salicilic acid.
They figured out how to synthesize pure medical grade aceetyl
salicilic acid, and after a couple of years of testing,
Beyar patented this effective and easier on the stomach medication
(03:18):
under the trade name aspirin in eighteen ninety nine. They
got the name by combining a for a setyl with
a word derived from spyriea, which is the genus name
for metal sweets, which are other plants that you can
get salasin from. Today, the name aspirin has been role
generic in a number of countries. There's actually a bit
(03:40):
of a debate now about who at Bayer was responsible
for synthesizing this compound. For decades, corporate lore said it
was a junior chemist by the name of Felix Hoffmann,
whose father had arthritis, so he was motivated to help
ease his side effects from taking salicilic acid. But one
hundred years after aspirn came out, at the turn of
(04:02):
the twenty first century, credible evidence arose that Hoffmann's boss,
one Arthur Eisngrun, was more responsible, but because Eisngrune was Jewish,
his involvement was downplayed. With the rise of the Nazi regime,
It's a mystery of history. Another long running mystery that
has since been solved is how aspirin works in the body.
(04:25):
We didn't know for sure until the nineteen seventies, when
a team of pharmacologists and biochemists came up with proof,
for which they were rewarded the Nobel Prize in Medicine
in nineteen eighty two. It took humanity all of these
millennia to figure it out, partially because pain is complicated
like no one is totally sure how it works, and
(04:47):
the more we learn, the more questions seem to arise. Okay,
like all other sensory experiences. Pain exists only because your
brain says it does, your body's way of telling you
that something has gone wrong that needs your attention. Let's say,
for example, that you hit your thumb with the hammer
(05:08):
instead of the nail you're aiming for. Please don't try
this at home. Now. Your thumb has nerve endings in it.
These are little detectors in your joints and skin that
feel things like heat, vibration, and everything from featherlight touch
to the big crushing shock of being hit with the hammer.
(05:29):
There are different receptors for each of these types of sensations. Also,
when you hit your thumb and damage that tissue, nearby
cells will release some chemicals that make your nerve endings
register the crushing shock more strongly, like turning up the volume.
Some of those chemicals are ones called prostaglandins. So very basically,
(05:52):
you smash your thumb and the nerve endings involved send
now strong signals up through your nervous system and into
your brain, which which decides that these signals mean hey,
that hurts. The pain you experience is useful information because
it tells you that your thumb is damaged and that
you should put the hammer down and be careful with
(06:12):
the thumb until it's healed. Prostaglandins contribute only a portion
of the total pain signal, but it's an important portion,
and prostaglandins also help cause the site of the injury
to swell up. This bathes the injured tissue in blood
and helps rush immune system resources into protect it and
(06:33):
start the healing process. Basically, it's a good system, but
a few problems can arise. First Off, pain is not
a neutral feeling. It's emotionally upsetting, so once you've registered
your bodily damage, having that pain signal continue isn't fun
or even particularly useful. Secondly, something's hurt without there being
(06:59):
a hammer or or open flame, or some other source
of damage that you can avoid. You might get a
headache because your scalp and neck muscles are contracted from stress,
or because a blood vessel in your brain has a spasm. Thirdly,
as we've talked about before on the show, autoimmune conditions
like arthritis or psoriasis can cause your immune system to
(07:21):
turn on healthy tissue, causing too much inflammation, which itself
can be painful and even damaging. These processes appear to
involve prostaglandins as well. Aspirin helps with these problems by
stopping your tissue from releasing prostaglandins by preventing your cells
from making them. Okay, cells working in damaged tissues produce
(07:46):
prostaglandins using an enzyme called cyclooxygenase two, or COX two.
COX two can be found and lots of normal tissues,
but much more of it is made in tissue that's
been hurt in some way. Aspirin, as it turns out,
sticks to COX two and won't let it do its job.
It's like sticking gum in a lock instead of a key.
(08:10):
Don't try this at home either, take my word for it.
The lock will not open with gum in it, and
COX two can't work with aspirin stuck in it. So
by taking aspirin you don't stop the problem that's causing
the pain, like the tight muscles in your scalp or
the hammer damaged finger. But it does lower the volume
(08:30):
on the pain signals going through your nerves to your
brain and will prevent some inflammation from happening. This is
not a targeted therapy. Aspirin doesn't know where to go
in your body. When you take a tablet, it dissolves
in your stomach or small intestine, and your body absorbs
it from there into your bloodstream, which carries it through
(08:50):
your entire body. Although it circulates pretty much everywhere, it
only works where there are prostaglandins being made, including the
area where it hurts. But the solution is not permanent.
As with almost all chemicals, your body has a way
of getting rid of aspirin. In this case, your liver, stomach,
and other organs convert aspirin to salicylic acid. Your liver
(09:15):
then sticks other chemicals onto the salisilic acid so that
your kidneys can filter it out of your blood and
send it out through your urine. The whole process takes
about four to six hours, so you have to take
another pill at that time if you want to keep
the effect going. This is also a good but imperfect system.
(09:37):
There are places in your body that need prostaglandins for
various reasons. For example, in your stomach, a related enzyme
COX one makes a prostaglandin that seems to keep your
stomach lining nice and thick. Aspirin prevents that too, meaning
that taking aspirin over time can cause your stomach lining
(09:57):
to get thin, allowing your digestive juices to irritate it.
This is probably the biggest reason why aspirin upsets stomachs,
not only because it's an acid, as Bayer's chemists thought.
There are other places in the body where prostaglandins have
a job. In normal tissues, such as the blood. Some
(10:18):
types of prostaglandins cause tiny particles in your blood known
as platelets, to stick together in forming blood clots. By
inhibiting prostaglandin production, aspirin slows down clot production. This can
be bad, like if you have a bloody nose or
a cut, in which cases you absolutely want a clot
(10:38):
to form, so maybe avoid taking aspirin there. But blood
clots can hurt us, as can happen in heart attacks
when clots clog the blood vessels that carry oxygen through
your hard working heart. That's why aspirin is recommended by
healthcare providers to some people looking to prevent a heart
(10:59):
attack or to recover from one. The way that aspirin
lowers fevers also has something to do with its inhibition
of prostaglandins, this time in the hypothalamus, which is a
part of the brain that helps control body temperature, among
other things. This one might be more complicated, though research
is ongoing. But okayke anything you can take in. There
(11:23):
is such thing as too much aspirin, and it can
cause some unwonted side effects like bleeding or bruising if
it prevents blood clots and upset or damage to the stomach.
A risk of these side effects increases when you take
aspirin alongside some other drugs like other painkillers, plus blood thinners,
and many antidepressants. Additionally, aspirin is not recommended for bringing
(11:47):
down the fever of kids with virus infections like the
flu or chicken pox, because aspirin is associated with a
deadly condition called rhye syndrome. In cases like those, drome
causes brain damage, so aspirin should not be given to
children and less directed by a healthcare provider for a
specific condition. But for these reasons, scientists have found other
(12:12):
chemicals related to aspirin that have some of its good
effects and lack some of its bad ones. For example, abuprofin,
sold under the brand names advil or motrin, and nepoxin
or a leave can also treat pain, swelling and fever,
but seem to have less of effect on platelets than
aspirin does. All three of these are in a class
(12:33):
called non steroidal antiinflammatory drugs because they decrease swelling, but
they're not steroids, which are the most potent antiin inflammatories
that we have. A Different class of medicines related to
aspirin includes acetaminifin or tailanol, which decreases fevers and pain
but doesn't affect inflammation or your stomach as much as
(12:54):
nonsteroidal anti inflammatories do, and all of these options are
generally safer for kids. Even with different options, asprin is
still something of a wonder drug today. More research is
being done to see if it might be able to
help with other conditions, like some forms of cancer. As always,
human bodies are complicated, so talk to a healthcare provider
(13:16):
if you have any questions. But the next time you
get out a hammer, think of those thousands of years
of willow use and maybe set aside an aspirin or two.
It's best to be prepared just in case you hit
the wrong nail. Today's episode is based on the article
(13:37):
asprin one oh one on HowStuffWorks dot com, written by
doctor Lucas Hoffman. Brain Stuff is a production of iHeartRadio
in partnership with HowStuffWorks dot com, and it's produced by
Tyler Playing. For more podcasts from my heart Radio, visit
the iHeartRadio app, Apple Podcasts, or wherever you listen to
your favorite shows.
BrainStuff News
Host
Lauren Vogelbaum
Popular Podcasts
Betrayal Weekly
Betrayal Weekly is back for a new season. Every Thursday, Betrayal Weekly shares first-hand accounts of broken trust, shocking deceptions, and the trail of destruction they leave behind. Hosted by Andrea Gunning, this weekly ongoing series digs into real-life stories of betrayal and the aftermath. From stories of double lives to dark discoveries, these are cautionary tales and accounts of resilience against all odds. From the producers of the critically acclaimed Betrayal series, Betrayal Weekly drops new episodes every Thursday. If you would like to share your story, you can reach out to the Betrayal Team by emailing them at betrayalpod@gmail.com and follow us on Instagram at @betrayalpod and @glasspodcasts. Please join our Substack for additional exclusive content, curated book recommendations, and community discussions. Sign up FREE by clicking this link Beyond Betrayal Substack. Join our community dedicated to truth, resilience, and healing. Your voice matters! Be a part of our Betrayal journey on Substack.
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com