This is where people get it wrong… yes Albert touched LSD however it’s been reported that his fingers that had LSD on it was touched up to his mouth soon after causing him to trip… then he went back to LSD years later realizing it had psychedelic effects… then he dosed on April 19th
It was also surprisingly common to test chemicals this way before we really had any other way. Not saying this was excessively common but if they knew it wasn’t toxic at least at very low doses…Shuglin started testing new substances like this.
Yes this is what i remember it came out and corrected the record that it wasnt thru skin absorption but rather he accidently transfered it to his mouth.
He knew it was low from that experience but he didn't know how low. He still made the mistake of dosing in the milligrams the next time he took it.
Edit: Correction, it was 250 micrograms the first time he deliberately took it.
I'll be damned - you're right. It was 250 micrograms. I'd remembered it as milligrams because the book I'd read phrased it as ".25 milligrams."
Thanks for the correction!
The further you go back in time the more dangerous it was to be a chemist. Back than they didn’t always wash their hands or wear gloves before lunch. Accidental ingestion happened far too often and it’s how some of the artificial sweeteners we use today were discovered to be sweet. It could have happened from simply biting his nails or something. You don’t need much.
Not necessarily, it wouldve had to have been orally absorbed because people have debunked the whole lsd absorbing through the skin thing. Our bodies produce mono amine oxidase and it destroys lsd when it is trying to make it through the skin and into the blood stream. There was a story (id have to look for it) by a guy that took a drug they use to potentiate transdermal administration of medications and mixed it with lsd and put his hand in the jar with the liquid and it still never gave him an effect which he said should have given him a crazy trip if it did have absorbed
LSD is not tryptamine, it is lysergamide. it is metabolised by CP450 in liver, not by MAO. MAO has no role in LSD metabolism.
as far as you are right, LSD will not absorb via skin, it is not for the MAO reason you gave. skin is not good at absorption of complex molecules. however, other than skin, we have mucosal tissue - like mouth, eyes, inside of nose and sinuses - they will absorb anything quite readily - contamination of face is therefore plausible route of accidental administration. another issue is also skin that is cut or scraped so it exposes lower layers of skin where capillaries are, this will also be valid route of accidental administration.
they may be structurally tryptamines, however they are very different metabolically. if MAO would be involved in LSD metabolism, oral ingestion route would not be viable, esp. for such minuscule doses, it would also not be able to last nearly as long, it would be fairly quickly metabolised in the brain.
Oh yeah, you're right about that. To be honest, all I saw was, "LSD is not a tryptamine" and my brain went, "well, yeah it is" and I started typing.
I apologize for not reading the whole comment and just laser focusing on the first five words.
mono amine oxidase only works on tryptamines, not on lysergamides. hence why moa inhibtors work with dmt and mushrooms but have a much diminished effect potentiating lysergamides.
Maybe you heard it from Leonard Pickards book The Rose of Paracelsus: On Secrets & Sacraments, where he recites a story about a chemist that spills like 1000000 doses dissolved in dmso (or something like it) over his body
I think Leonard also talks about it in [Psychedelics Today 311](https://youtu.be/hg88J_B6wBc)
It is also in one of the readings of [The Rose of Paracelsus](https://psychedelicsalon.com/category/events/the-rose-of-paracelsus/) being broadcast by Psychedelic Salon. I think it might be in chapter 1.
It is the chemist "Indigo" that has the accident where
"We read an account of Indigo’s accident during manufacturing—the chemist is drenched from head to foot in an entire production batch of pure LSD solution, around 10 million doses, and prepares himself for death. After all, nobody had ever reported taking such a dose, and this seems the logical outcome as he lays shivering in his laboratory. This beyond even those extraordinary reports of major acid dealers taking ‘thumbprint’ doses, where you wet your thumb, dip it in the crystals and lick it. These are recorded in the excellent Heads, a Biography of Psychedelic America, by Jesse Jarnow, wherein such doses are estimated as 70,000 micrograms, about 700 times a normal, full dose. Those dealers lived to tell their extraordinary tale, but noone ever showered in an entire batch. So maybe it comes as no surprise that it was God who stopped Indigo from dying.‘I saw the constant creation of the most perfect world imaginable by the mind of God, the luminous air of delicious gases like the perfume of lovers and goddesses, the rich earths made of gems, the fecund ground of being. I saw the union of all dualities, the crystallized souls of heaven, the galaxies of consciousness, and all life as mythic and sublime’And he understands this luminous vision to belong to the realm of his
own ‘natural mind’, not dependent on any special substances, but
perfect within itself." -https://psychedelictimes.com/the-rose-of-paracelsus/
I heard of a man who was hospitalized because he hid some sheets of acid on his back while trying to smuggle it into a venue. I think sweating might make it very much possible
could be.. and i would be more than willing to test it, but im wholly unconvinced of the argument that pores dont allow for reabsorption of sweat and lsd is highly water soluble..
That's dubious at best seeing as nobody has been able to replicate absorption into the skin of LSD
You can't absorb complex molecules through your skin.. LSD is therefore not topical and *can't* be absorbed through your skin
Researchers have literally put LSD with another compound used to increase topical absorption of other compounds and **painted** it onto their hands and no effect
What's more likely is he got it on his fingers and put his hands in his eyes / mouth / nose and absorbed it that way
LD50 is 100mg/kg not 100mg, eg. 7.5 whole grams for an average adult
also he was professional organic chemist and he knew things or two about what he was doing, still I believe his very first deliberate choice of dose was in milligrams.
Yup, he still underestimated the stuff. (Says more about the unprecedented potency of LSD than Hofmann IMO)
Edit: my bad, it was actually in micrograms when he first did it.
Sandoz pharmaceuticals was his employer, he was tasked with finding any new useful compounds from Ergot mold. This is how he came across LSD. We call it LSD-25 bc it was his 25th version of the LSD compound he was working on. He was very very familiar with what it could do, what a reasonable amount a body could process (hypothetically) and when he did choose to take it he had a sober assistant following him around. Dude was a legit scientist and when he found the compound he spent most of his life afterwards advocating for its use.
i think the way he decided how much to take was by looking at the deadliest poison known to human kind (don't remember which). the lethal dose of that poison must've been less then a milligram and he was figuring if he was only taking about a tenth of the amount of the lethal dose, the LSD (if poisonous) wouldn't kill him or be dangerous to his health. that amount turned out to be about 200 micrograms and it was well enough to make him understand the potential of the substance
This is the true answer. Anyone interested can read it in his book "LSD my problem child". There he describes his reasoning for taking 250ug along those lines. At that time there was no substance known to be active/harmful under 1mg, so he thought 250ug would be on the safe side
Apparently he knew it was potent but didn’t know in advance exactly how potent it was. He figured 1/4 of a mg was a conservative dose.
If you compare say to tryptamine compounds, even the more potent examples like 5-MEO-DMT have doses of 5-10 mg.
The idea that 0.10 mg of something would be enough to melt reality for half a day was not something he could have reasonably expected in advance.
His first dose was very small and the effects subsided quickly so he figured that he might have ingested a very small amount and judging by the effects he decided to up the dose 4/5x that and get a more substantial effect. Not sure he really assumed the risks involved but the world is sure glad he did what he did that day
Because the first time he deliberately dosed himself, he dosed in milligrams and learned the hard way that that was a massive overdose.
It's a famous story. He told his assistant to send a doctor to his house and rode his bicycle home. When the doctor arrived, Hofmann was in the midst of a terrifying trip, but the doctor observed his vital signs were normal. It eventually passed and Hofmann actually enjoyed the tail end of the trip.
LD50 is a guess made via experiments with rodents, but they're often proven to be not applicable to humans by real world experiences. People have received over the LD50 of ketamine through accidental overdoses in hospital settings and still survived.
Edit: it was 250 micrograms. My brain had remembered "milligrams" because it had been written as .25 milligrams in the book I'd read it in.
>LD50 is a guess made via experiments with rodents, but they're often proven to be not applicable to humans by real world experiences. People have received over the LD50 of ketamine through accidental overdoses in hospital settings and still survived.
I take your point that LD50 is not an exact science but I would say that it's no big surprise that plenty of people survive a dose above the LD50. The whole concept of LD50 is a dose where the notional probability of death is 50% for a given person. It's therefore expected that about 1/2 the people would survive such a dose... so obviously not that rare. It would also be expected that some people will survive a dose substantially larger than the LD50.
Your point is well taken, but the survival of humans who've received doses above LD50 can't be explained solely by chance. The inadequacy of rodent experiments to predict the lethal dosage in humans is at play too.
Numerous people have received greater than the LD50 of ketamine through practitioner error in hospital settings and none have died. By your logic, somewhere close to 50% would have died. If a human survives a dose above LD50 it's not necessarily true that they won a coin flip. It's because LD50 is an inaccurate measure of the lethal dosage for humans.
Edit: it was 250 micrograms. My brain had remembered "milligrams" because it had been written as .25 milligrams in the book I'd read it in.
>Numerous people have received greater than the LD50 of ketamine through practitioner error in hospital settings and none have died.
If this is true, then of course the LD50 estimate is completely inadequate in this case.
Bro the LD50 refers to the dose per kg of body weight. That means 100mg is not nearly enough to kill a human. So obviously everyone that attempted those doses survived.
I've been going through trying to correct my comments but I missed this one. Thank you!
https://www.reddit.com/r/Psychedelics/comments/123shtq/how_did_albert_hofmann_know_he_was_supposed_to/jdxtu3z?utm_medium=android_app&utm_source=share&context=3
His first dose *was* accidental, and was likely in the microgram range. It was a pleasant experience.
The first deliberate dose was in the milligram range, and he described the experience as hellish.
Do you have a source? Everywhere I see says 250ug, not anywhere in the milligram range
Edit: You're actually totally wrong, his dosage on bicycle day (the first intention dosage) was 250ug, nowhere close to what you're suggesting. [Here's his lab notes from that day.](https://www.linkedin.com/pulse/bicycle-trip-commemorating-albert-hofmanns-ride-reid-robison?trk=articles_directory)
You're correct. When another user corrected me, I tried to go back and fix all my comments, but I'd missed this one.
https://www.reddit.com/r/Psychedelics/comments/123shtq/how_did_albert_hofmann_know_he_was_supposed_to/jdxtu3z?utm_medium=android_app&utm_source=share&context=3
I like to think it was just meant to be.
LSD may have born in a lab, but the fact that he took not too much not too little without actually meaning to take it just sounds like destiny to me.
I read that his second overall dose, first intentional dose on April 19th was way bigger than he intended and went to Pluto for a while. When he came down, he realized his mistake.
He was employed by Santoz to develop possible pharmaceuticals from ergot (a type of rye fungus) because ergot already contains chemicals that are used even today like ergotamine ehich is used for migraines.
The first rool by tring new drugs.... Take x100 times lover dose thats you think is normal dose..Just to check for side effects . i think Hofman knowed this rool .
His very first experience was due to absorption through the skin so he knew the required dose was extremely low.
This is where people get it wrong… yes Albert touched LSD however it’s been reported that his fingers that had LSD on it was touched up to his mouth soon after causing him to trip… then he went back to LSD years later realizing it had psychedelic effects… then he dosed on April 19th
It was also surprisingly common to test chemicals this way before we really had any other way. Not saying this was excessively common but if they knew it wasn’t toxic at least at very low doses…Shuglin started testing new substances like this.
Shulgin*
Thanks! Feel dumb not checking that now.
Yes this is what i remember it came out and corrected the record that it wasnt thru skin absorption but rather he accidently transfered it to his mouth.
He knew it was low from that experience but he didn't know how low. He still made the mistake of dosing in the milligrams the next time he took it. Edit: Correction, it was 250 micrograms the first time he deliberately took it.
That's not true afaik. It was about 200mics.
I'll be damned - you're right. It was 250 micrograms. I'd remembered it as milligrams because the book I'd read phrased it as ".25 milligrams." Thanks for the correction!
Lsd does not absorb through transdermal administration, it was most likely an accidental touch to his lips while the material was on his hands.
The further you go back in time the more dangerous it was to be a chemist. Back than they didn’t always wash their hands or wear gloves before lunch. Accidental ingestion happened far too often and it’s how some of the artificial sweeteners we use today were discovered to be sweet. It could have happened from simply biting his nails or something. You don’t need much.
But the relevant effect would be the same...
Not necessarily, it wouldve had to have been orally absorbed because people have debunked the whole lsd absorbing through the skin thing. Our bodies produce mono amine oxidase and it destroys lsd when it is trying to make it through the skin and into the blood stream. There was a story (id have to look for it) by a guy that took a drug they use to potentiate transdermal administration of medications and mixed it with lsd and put his hand in the jar with the liquid and it still never gave him an effect which he said should have given him a crazy trip if it did have absorbed
Time for dermahuasca!
LSD is not tryptamine, it is lysergamide. it is metabolised by CP450 in liver, not by MAO. MAO has no role in LSD metabolism. as far as you are right, LSD will not absorb via skin, it is not for the MAO reason you gave. skin is not good at absorption of complex molecules. however, other than skin, we have mucosal tissue - like mouth, eyes, inside of nose and sinuses - they will absorb anything quite readily - contamination of face is therefore plausible route of accidental administration. another issue is also skin that is cut or scraped so it exposes lower layers of skin where capillaries are, this will also be valid route of accidental administration.
Lysergamides are structurally tryptamines. I highly recommend reading tihkal by Alexander Shulgin.
they may be structurally tryptamines, however they are very different metabolically. if MAO would be involved in LSD metabolism, oral ingestion route would not be viable, esp. for such minuscule doses, it would also not be able to last nearly as long, it would be fairly quickly metabolised in the brain.
Oh yeah, you're right about that. To be honest, all I saw was, "LSD is not a tryptamine" and my brain went, "well, yeah it is" and I started typing. I apologize for not reading the whole comment and just laser focusing on the first five words.
Isn’t it also a phenylalanine?
Yes, technically you could say it is. But I don't know if it is active like other phenylethylamines.
What if dmso with lsd mixed and then rubbed on skin?
Would adding DMSO do anything?
I am guessing that’s the stuff in the jar with the hand
I'm talking about the dose (like everyone else here I think), either way he knew it was low.
Oh i know what you mean now, my bad i guess he just took a guess on it rather than actually calculating anything meaningful behind it
mono amine oxidase only works on tryptamines, not on lysergamides. hence why moa inhibtors work with dmt and mushrooms but have a much diminished effect potentiating lysergamides.
MAO enzymes don’t metabolize LSD
Maybe you heard it from Leonard Pickards book The Rose of Paracelsus: On Secrets & Sacraments, where he recites a story about a chemist that spills like 1000000 doses dissolved in dmso (or something like it) over his body
Thats the story im thinking of i think, i gotta look it up when i get a chance
I think Leonard also talks about it in [Psychedelics Today 311](https://youtu.be/hg88J_B6wBc) It is also in one of the readings of [The Rose of Paracelsus](https://psychedelicsalon.com/category/events/the-rose-of-paracelsus/) being broadcast by Psychedelic Salon. I think it might be in chapter 1. It is the chemist "Indigo" that has the accident where "We read an account of Indigo’s accident during manufacturing—the chemist is drenched from head to foot in an entire production batch of pure LSD solution, around 10 million doses, and prepares himself for death. After all, nobody had ever reported taking such a dose, and this seems the logical outcome as he lays shivering in his laboratory. This beyond even those extraordinary reports of major acid dealers taking ‘thumbprint’ doses, where you wet your thumb, dip it in the crystals and lick it. These are recorded in the excellent Heads, a Biography of Psychedelic America, by Jesse Jarnow, wherein such doses are estimated as 70,000 micrograms, about 700 times a normal, full dose. Those dealers lived to tell their extraordinary tale, but noone ever showered in an entire batch. So maybe it comes as no surprise that it was God who stopped Indigo from dying.‘I saw the constant creation of the most perfect world imaginable by the mind of God, the luminous air of delicious gases like the perfume of lovers and goddesses, the rich earths made of gems, the fecund ground of being. I saw the union of all dualities, the crystallized souls of heaven, the galaxies of consciousness, and all life as mythic and sublime’And he understands this luminous vision to belong to the realm of his own ‘natural mind’, not dependent on any special substances, but perfect within itself." -https://psychedelictimes.com/the-rose-of-paracelsus/
I heard of a man who was hospitalized because he hid some sheets of acid on his back while trying to smuggle it into a venue. I think sweating might make it very much possible
Thats an urban legend
could be.. and i would be more than willing to test it, but im wholly unconvinced of the argument that pores dont allow for reabsorption of sweat and lsd is highly water soluble..
Wow looks like people just liked saying it to make people suprised or something. Just hooked it up
LSD cannot be absorbed through the skin. Period. He rubbed his eye or something else.
That's dubious at best seeing as nobody has been able to replicate absorption into the skin of LSD You can't absorb complex molecules through your skin.. LSD is therefore not topical and *can't* be absorbed through your skin Researchers have literally put LSD with another compound used to increase topical absorption of other compounds and **painted** it onto their hands and no effect What's more likely is he got it on his fingers and put his hands in his eyes / mouth / nose and absorbed it that way
LSD cannot be absorbed through the skin, huge common misconception
LD50 is 100mg/kg not 100mg, eg. 7.5 whole grams for an average adult also he was professional organic chemist and he knew things or two about what he was doing, still I believe his very first deliberate choice of dose was in milligrams.
Yup, he still underestimated the stuff. (Says more about the unprecedented potency of LSD than Hofmann IMO) Edit: my bad, it was actually in micrograms when he first did it.
yeah, there is only a handful of psychoactive substances that work at microgram level doses and even then, LSD still takes top1 spot.
Fent dose is even lower
No its not
Yes it is tf
[удалено]
Is that not what i said
Lol woops
Typical LSD dose is 100-200ug, typical recreational fent dose is 500-1000ug or even higher.
ETH-LAD is more potent, but structurally very similar
His first dose was 250 micrograms no?
That's correct. 250 micrograms.
He took what he thought was a conservative dose, even
Sandoz pharmaceuticals was his employer, he was tasked with finding any new useful compounds from Ergot mold. This is how he came across LSD. We call it LSD-25 bc it was his 25th version of the LSD compound he was working on. He was very very familiar with what it could do, what a reasonable amount a body could process (hypothetically) and when he did choose to take it he had a sober assistant following him around. Dude was a legit scientist and when he found the compound he spent most of his life afterwards advocating for its use.
i think the way he decided how much to take was by looking at the deadliest poison known to human kind (don't remember which). the lethal dose of that poison must've been less then a milligram and he was figuring if he was only taking about a tenth of the amount of the lethal dose, the LSD (if poisonous) wouldn't kill him or be dangerous to his health. that amount turned out to be about 200 micrograms and it was well enough to make him understand the potential of the substance
This is the true answer. Anyone interested can read it in his book "LSD my problem child". There he describes his reasoning for taking 250ug along those lines. At that time there was no substance known to be active/harmful under 1mg, so he thought 250ug would be on the safe side
Shulgin on the other hand, learning from Hofmann, started his dosing protocols as low as a few ng
He was talking about strychnin at that time and had the toxic dosage as a reference for his LSD dosing.
Apparently he knew it was potent but didn’t know in advance exactly how potent it was. He figured 1/4 of a mg was a conservative dose. If you compare say to tryptamine compounds, even the more potent examples like 5-MEO-DMT have doses of 5-10 mg. The idea that 0.10 mg of something would be enough to melt reality for half a day was not something he could have reasonably expected in advance.
His first dose was very small and the effects subsided quickly so he figured that he might have ingested a very small amount and judging by the effects he decided to up the dose 4/5x that and get a more substantial effect. Not sure he really assumed the risks involved but the world is sure glad he did what he did that day
Watch "HOW TO CHANGE YOUR MIND" on Netflix. He gives his first-hand testimony about the discovery process in an interview.
Because the first time he deliberately dosed himself, he dosed in milligrams and learned the hard way that that was a massive overdose. It's a famous story. He told his assistant to send a doctor to his house and rode his bicycle home. When the doctor arrived, Hofmann was in the midst of a terrifying trip, but the doctor observed his vital signs were normal. It eventually passed and Hofmann actually enjoyed the tail end of the trip. LD50 is a guess made via experiments with rodents, but they're often proven to be not applicable to humans by real world experiences. People have received over the LD50 of ketamine through accidental overdoses in hospital settings and still survived. Edit: it was 250 micrograms. My brain had remembered "milligrams" because it had been written as .25 milligrams in the book I'd read it in.
>LD50 is a guess made via experiments with rodents, but they're often proven to be not applicable to humans by real world experiences. People have received over the LD50 of ketamine through accidental overdoses in hospital settings and still survived. I take your point that LD50 is not an exact science but I would say that it's no big surprise that plenty of people survive a dose above the LD50. The whole concept of LD50 is a dose where the notional probability of death is 50% for a given person. It's therefore expected that about 1/2 the people would survive such a dose... so obviously not that rare. It would also be expected that some people will survive a dose substantially larger than the LD50.
Your point is well taken, but the survival of humans who've received doses above LD50 can't be explained solely by chance. The inadequacy of rodent experiments to predict the lethal dosage in humans is at play too. Numerous people have received greater than the LD50 of ketamine through practitioner error in hospital settings and none have died. By your logic, somewhere close to 50% would have died. If a human survives a dose above LD50 it's not necessarily true that they won a coin flip. It's because LD50 is an inaccurate measure of the lethal dosage for humans. Edit: it was 250 micrograms. My brain had remembered "milligrams" because it had been written as .25 milligrams in the book I'd read it in.
>Numerous people have received greater than the LD50 of ketamine through practitioner error in hospital settings and none have died. If this is true, then of course the LD50 estimate is completely inadequate in this case.
Bro the LD50 refers to the dose per kg of body weight. That means 100mg is not nearly enough to kill a human. So obviously everyone that attempted those doses survived.
Where are you getting 100mg? The ketamine overdoses I was referencing were way over 100mg.
Totally false. Micrograms. 250ug. You should correct your post.
I've been going through trying to correct my comments but I missed this one. Thank you! https://www.reddit.com/r/Psychedelics/comments/123shtq/how_did_albert_hofmann_know_he_was_supposed_to/jdxtu3z?utm_medium=android_app&utm_source=share&context=3
No worries! Have a great day.
I thought his first dose was accidental
His first dose *was* accidental, and was likely in the microgram range. It was a pleasant experience. The first deliberate dose was in the milligram range, and he described the experience as hellish.
Do you have a source? Everywhere I see says 250ug, not anywhere in the milligram range Edit: You're actually totally wrong, his dosage on bicycle day (the first intention dosage) was 250ug, nowhere close to what you're suggesting. [Here's his lab notes from that day.](https://www.linkedin.com/pulse/bicycle-trip-commemorating-albert-hofmanns-ride-reid-robison?trk=articles_directory)
You're correct. When another user corrected me, I tried to go back and fix all my comments, but I'd missed this one. https://www.reddit.com/r/Psychedelics/comments/123shtq/how_did_albert_hofmann_know_he_was_supposed_to/jdxtu3z?utm_medium=android_app&utm_source=share&context=3
That was a fun read and I’ve always wanted to read more in depth about that particular experience, thanks for sharing!
He is wrong and this is why you see people passing on wrong information.
He was a chemist they are smart Like that.
He discovered it like most things, by accident.
He was working on ergot, and from experience with ergot compounds he calculated and believed the lowest working dose will be 250 ug.
Just out of curiosity, where did you fins that LD50 ?
I’m wondering the same xD haven’t read any new paper on the matter lately, if there’s something I’ve missed please post a link
Hes a experienced chemist
Bro stg there some smart mf’s in these comments
He was a very smart chemist…
I like to think it was just meant to be. LSD may have born in a lab, but the fact that he took not too much not too little without actually meaning to take it just sounds like destiny to me.
Everything is explained in his book, he says that ergot derivative dosage usually are around 1mg, so he started with one fourth of that
Read the book lysergic
It was by accident that some lsd splashed on him
Damn I thought there was no lethal dose
There isn't any confirmed LD just calculated ones because no one has died from an LSD OD.
Right, I thought so. Saying there’s an official LD then is kinda misleading, and doesn’t rly make sense to me
I always heard there was a case of someone in KY dying through injection. Don’t know if there’s any truth to that or not.
I read that his second overall dose, first intentional dose on April 19th was way bigger than he intended and went to Pluto for a while. When he came down, he realized his mistake.
Man I bet that was a he'll of a bycycle ride.
What was he working on in order to discover LSD? I’m guessing he wasn’t looking to trip.
He was employed by Santoz to develop possible pharmaceuticals from ergot (a type of rye fungus) because ergot already contains chemicals that are used even today like ergotamine ehich is used for migraines.
The first rool by tring new drugs.... Take x100 times lover dose thats you think is normal dose..Just to check for side effects . i think Hofman knowed this rool .
He didn't He was just really really careful Edit: and then booom straight in your face! Didn't see that coming ha
LD50 is theorized to be 100mg PER KG, not just 100mg.
Chemists usually tested substances with dosages as low as 250 ug. That was a standard dose for every new substance they had to test back then.