The LD50 (dose at which 50% of administrations are fatal) of LSD is approximately 55mg/KG in mice. Assuming that the human body is reasonably similar in metabolism, that means that in order to kill an average human weighing 70KG (~155lb), they would have to ingest 3,850mg of LSD to die half of the time.

LSD is -the- most potent psychoactive currently known, and the psychotropic threshold is about 35-70ug (micrograms). Street doses are around 100ug.

A subject would have to ingest 38,500 street doses of unadulterated LSD* to die half of the time. If street prices are $5 per hit (conservative), it would cost $192,500 to obtain this much LSD.

Can you die from LSD poisoning? Yes, but it has yet to be documented in a human. Can you die from self-injury or recklessness while out of your mind on LSD? Absolutely, it happens all the time.

* LSD is often mixed with amphetamine derivatives, methamphetamine, caffeine, phencyclidine, pseudoephedrine, all of which are cardiotoxic and will kill you thousands of times faster than LSD itself, which is a remarkably safe drug, systemically.

You could die of heart failure caused by intense fear. I believe fear can kill you.
A very intense LSD rush caused by multiple tabs can speed the heart up to 200 beats a minute and theoretically could be dangerous to a weak heart.
I once thought I was going to die on LSD as my heart was beating too fast.I was in an ambulance rigged up to a heart monitor reading 190 beats a minute. The more I worried about my heart rate the higher it got and I had extreme palpitations.
Im sure you could die in rare instances from this overload on the heart.
LSD can also cause fatal dehydration theoretically, thought it is probably not the LSD itself but what it is laced with that can dry one out too much.

I knew someone who died whilst on LSD. Whilst it was not the LSD itself that killed him it was the use of the drug that caused him to jump from a high building resulting in a coma and eventual death.
Your choices are your own, this isn't the place for moralising, but yes, you can definetely die through taking LSD.

It is totally possible to die from an LSD overdose.

While I am not going to get on my soapbox and scream to the heavens to either use or not use any drugs, LSD can be a very powerful drug.

It is quite correct to say that most people who die having used LSD do so as a result of the poor decisions they make while strung out on a trip, this usually amounts to things like getting behind the wheel of a car ETC. (I’ve never seen a DOCUMENTED case of someone believing they can fly and jumping off a building)

However, there have been a number of people who have died as a result of Cardiac Arrest due to a bad trip. They just have such a scary trip that they almost literally “talk” themselves in to a Heart Attack. In this case, it isn't the drug per se that cause the Heart Attack though.

Even worse than this are the people that have gone catatonic. I couldn’t tell you if this was because of a bad trip or bad Acid, but to me, it’s a fate WORSE than death.

As far as I know people don't usually die as a physical result of the drugs, although people can kill themselves and others while on the drugs. LSD will make you crazy. DO NOT TRY LSD.

This is patently absurd from a logical standpoint (self-induced cardiac arrest under the influence of LSD).
It's in that same category wherein someone is asleep and dreaming that they are on a high cliff or building and in that dream they fall to their death -- whereupon they are alleged to die in their sleep.
Who came back from the dead to tell anyone the tale?
Who "talked themself" into a cardiac arrest, died and told the tale?
There is no supporting documentation regarding such a phenomenon and is as relevant here as any other imaginary "old wives tale." It never happened.

All of these answers are correct. If you are perfectly healthy human being above the age of 16 years old, you probably wont even die if you take LSD hundreds of times. Anyone who would tell you that you could die from a just 1 or 2 hits your first time is just one of those nazi anti drug DARE program people. They have never done it, never researched it, and are only trying to stike the fear of some sort of 'God' into you. LSD can be frightful or dangerous if takin in the wrong place and in the wrong state of mind, but as far as physically dropping dead from a hit of LSD? COMPLETELY REDICULOUS.... Have fun, trip well.
P.S. : definatly listen to the people that said 'clear your mind and enjoy the ride'. You MUST relax and go into it with a carefree positive attitude or you will just end up tripping balls and wishing you were sober again.

Last had LSD in 1986.Suffered horribly that night,22yrs later still have not recovered,and certain now, I never will. YOU HAVE BEEN WARNED

LSD is one strange drug. You seem to build "resistance" to it incredibly rapidly, almost as you are taking it. I knew a very few people who took it on consecutive days or more and they all told me the same thing. They were up to doses about 3-5 times higher to get the same effects in no time.

One dealer I knew was busted in his home with LSD on himself. He ate a 50 sheet before being loaded into the back of a police cruiser. I tried this stuff and 3 was a huge trip. My buddy told me he got off incredibly rapidly, but he really could not distinguish the intensity from the 10 he usually took of this particular batch. He was one of those folks I knew that did take LSD daily for a short time.

If ever someone was gonna OD on LSD this should have done it. This article is correct. The actual chemical cannot kill you in the types of doses any user would ingest.

It is one of the only recreational drugs I know of that has no real OD amount. I had heard that well before my buddy took his 50 but never really bought it till after that event.

The people that may have reportedly / supposedly died from cardiac arrest as a result of LSD use...
Most likely had an underlying cardiac or heart disease or problem.

That, or they could have been on a variety of medications that may have caused the heart rate to speed up before hand [speed or ADD medicine such as adderall, caffeine, nicotine, marijuana, ecstasy, etc.] which, when combined with the LSD, could have caused the heart rate to sky rocket rapidly.

Also, I've read that LSD increases body temperature and blood pressure. So, if the person taking it unknowingly has an underlying cardiac or heart problem, this may kick them into cardiac arrest or some blood pressure-related problem.

I've read that if LSD is taken with certain antidepressants, then the user goes into a state where they may or may not be aware at all of their state, in which they may endanger themselves and others. This, along with the possibility that the user unknowingly had an underlying mental illness, could cause someone to harm themselves or others, or do stupid things like jump off of buildings [which is reported, as I've noticed while watching a video on YouTube of an interview with Timothy Leary where a man -- I believe he was a Senator or something -- confronted Leary about how LSD caused the man's daughter to jump out of the 2nd story window to her death].

Basically, if you're scared of taking LSD, I can only give a basic little suggestion:
Look for the book "The Psychedelic Experience: A Guide Based on the Tibetan Book of the Dead" by Timothy Leary, and read it. It gives plenty of information about LSD and other psychedelic "trips" and how to have a good trip, and how to calm and pull yourself out of a bad trip. It was written by a variety of authors, including Timothy Leary -- who was one of the psychologists who led the LSD tests at Harvard University in the 1960s.

Also, read Aldous Huxley's "The Doors of Perception" and "Heaven and Hell", which are both philosophical studies of perception and psychedelic drug use [as Huxley himself used mescalin and LSD, and detailed the accounts and experiences in the books].

Reading guides and other users' experiences [from the 1950s and 1960s, as those who used it back then detailed it in a more research, and interesting way] would calm some fears, and would also allow for a more relaxing experience, in my opinion.

Like the Beatles song [and "Psychedelic Experience"] says,
"..Turn off your mind, relax, and float down stream."