O-Acetylpsilocin is a synthetically produced psychoactive drug and has been
suggested by David Nichols to be a potentially useful alternative to
psilocybin for pharmacological studies, as they are both believed to be prodrugs
of psilocin. However, some users report that O-acetylpsilocin's subjective
effects differ from that of psilocybin and psilocin. It is the acetylated form
of the psilocybin mushroom alkaloid psilocin and is a lower homolog of
4-AcO-DET, 4-AcO-MiPT and 4-AcO-DiPT. History
O-Acetylpsilocin and several other esters of psilocin were patented on
January 16, 1963 by Sandoz Ltd. via Albert Hofmann & Franz Troxler. Despite
this fact, psilacetin remains a psychedelic with a limited history of
use. It is theorized to be a prodrug for psilocin, as is psilocybin, which is
naturally occurring in various mushrooms. Psilacetin is O-acetylated
psilocin, whereas psilocybin is O-phosphorylated.
Chemistry O-Acetylpsilocin can be obtained by
acetylation of psilocin under alkaline or strongly acidic conditions. It is a
synthetic compound. However, it is believed to be a prodrug of psilocin,
which is natural and occurs in many mushrooms along with psilocybin.
O-Acetylpsilocin is more resistant than psilocin to oxidation under basic
conditions due to its acetoxy group. While O-acetylpsilocin is not well
researched, it is not as difficult to produce as psilocybin, and may be an
appropriate substitute for psilocybin in psychedelic research because of their
similar mechanism of action. Pharmacology
See psilocin for more details. In the body O-acetylpsilocin is
deacetylated to psilocin by deacetylases/acetyltransferases during
first pass metabolism and during subsequent passes through the liver. Its
ability to alter cellular metabolism by competing for the deacetylase enzyme
causes a perceptible loss of cellular heat generation capacity at doses
between 0.4 and 0.8mmol. Claims of subjective differences in
effect between the acetylated and not acetylated forms of psilocin; some users
report that O-acetylpsilocin lasts slightly longer; others report that it
lasts for a considerably shorter time. Many users report less body load and
nausea compared to psilocin. Some users find that the visual distortions
produced by O-acetylpsilocin more closely resemble those produced by DMT
than those produced by psilocin. These differences could be possible if
psilacetin is active itself and not merely as a prodrug.
Dosage A dose of O-acetylpsilocin is 8 mg - 30
mg. These are slightly lower than that of psilocin. Some report very strong
effects with 15 mg. A dose of 15 mg can produce a very profound experience, with
effects such as ego loss, strong visuals, and other effects similar to a
high dose of psilocin. Comparison to psilocin dosage suggests that
O-acetylpsilocin is somewhat more potent, and possibly more variable in
terms of subjective susceptibility. O-Acetylpsilocin seems to have a more
steep dose-effect curve than psilocin; therefore, caution should be taken,
especially with higher doses. There is no known LD50, as there are no reported
cases of fatal overdose. Dosages vary slightly depending on the
type of salt. The hydrochloride has a higher molecular mass and is therefore
less potent on a per weight basis than its freebase form; however, freebase
O-acetylpsilocin is relatively unstable and will degrade quickly at room
temperature. O-Acetylpsilocin is now most commonly distributed as the fumaric
acid salt. The fumarate is even less potent on a per weight basis, but is
also considerably more stable and will not degrade substantially at room
temperature. The ratio of hydrochloride to fumarate is approximately .93:1.
These above doses are taken from the site erowid.org, which advises potential
users of this chemical as a psychedelic drug: "Please note that the above doses
should only be used as a general outline. This chemical is still
relatively new, with a short history of human use. Every individual reacts
differently to every chemical." Effects
O-Acetylpsilocin is theorized to be metabolized into psilocin, as such is
the case with psilocybin; however, reports indicate that O-acetylpsilocin
may be active on its own. The effects of O-acetylpsilocin are therefore somewhat
similar to the effects of psilocybin and psilocin.
= Positive = Brightened colors / enhanced visual
perception Introspection and philosophical insights
Stimulation/ sensation / tingling Euphoria
Perceptual enhancement Empathy
Sexual arousal = Neutral =
Coldness/cold sensations Mydriasis
Hyperarousal Colour alteration/fluorescent
patterns/tracers Time dilation and nonlinearity
Synesthesia Dissociation
Sedation / Somnolence Lethargy, fatigue
Auditory hallucinations = Negative effects =
Mild to severe anxiety Shivering
Paranoia Stomach discomfort
Insomnia Overly-intense experience
Overwhelming ideas and/or racing thoughts
Difficulty speaking Motor impairment, vertigo
Confusion Significantly elevated heart rate
Hypothermia Legality
O-Acetylpsilocin is unscheduled in the United States. It may be considered an
analog of psilocin, which is a Schedule I drug under the Controlled Substances
Act of the USA, and as such sale for human consumption or possession to
ingest or use for illicit non-medical or industrial intents and purposes could be
prosecuted as crimes under the Federal Analog Act.
O-Acetylpsilocin is illegal in the UK under the Misuse of Drugs Act 1971.
O-Acetylpsilocin is illegal in Italy as it is an ester of a prohibited
substance. See also
4-MeO-DMT ALD-52
Ayahuasca Psilocybin
Psilocybin mushroom Psychedelic drug
Serotonergic psychedelic Tryptamine
References External links
Nichols, David; Fescas, Stewart. "Improvements to the Synthesis of
Psilocybin and a Facile Method for Preparing the O-Acetyl Prodrug of
Psilocin". Synthesis: 935–938. doi:10.1055/s-1999-3490. ISSN 0039-7881.
Retrieved 17 January 2012. 4-AcO-DMT information at
IsomerDesign.com Erowid 4-Acetoxy-DMT Vault
"Esters of Indoles" US Patent # 3,075,992 - Awarded to Sandoz Ltd. on
January 29, 1963.