LSD (lysergic acid diethylamide) is a chemically produced derivative of lysergic acid, which occurs naturally in ergot alkaloids, and belongs to the group of psychedelics. 

In 2020, 147 felts declared as LSD were handed in for analysis at the Drug Information Centre (DIZ) in Zurich. In a mobile drug checking carried out in the city of Zurich in 2020, eight felts declared as LSD were handed in and analysed. The results published here are not representative for the entire substance market of the city of Zurich. 

Risk assessment

In addition to the dose, the effect of LSD is always strongly dependent on one's own state of mind (set) and the environment (setting). When consuming LSD felts, there is a risk of ingesting misdeclared substances, pharmacologically active extenders and/or high-dose felts. The highly variable active substance content of LSD felts can lead to the unintentional ingestion of high doses, which increases the risk of a negative experience (bad trip). High doses increase this risk even for experienced users. Highly intense psychedelic experiences can be induced, which can be disturbing and frightening. In recent years, misdeclared LSD felts (felts containing another psychoactive substance instead of LSD) have been handed out at the DIZ time and again. Such misdeclarations can pose a high health risk, depending on the substance. Information and recommendations for low-risk consumption can be found at under LSD Safer Use

LSD content

In 2020, the LSD felts analysed in the DIZ contained an average of 79.3 μg LSD. This is 18.9 μg less than in the previous year. The range was from 3.7 μg to 205.5 μg LSD per felt. 72 % of the LSD felts contained less than 100 μg LSD (-12 %) and 18 % contained between 100 and 150 μg (-7 %). A warning was issued for 10 % of the felts because they contained more than 150 μg LSD (-5 %). 

LSD content in tartrate on felts 2011 - 2020, grouped (n=717) 

Unexpected substances and impurities 

In 2020, 12.8 % of the samples (-1.8 %) contained unexpected, potentially pharmacologically active substances. These were false declarations or unintentional contamination (smear contamination in minigrips already used with other substances). Two felts (1.2 % of the samples) were false declarations; of these, one felt each contained an NBOMe compound and DOC. In 2020, 26.9 % of the LSD felts analysed contained the non-psychoactive iso-LSD(-12.3 %). 

Unexpected pharmacologically active substances on LSD felts 2011-2020, in % of samples (n=771)4 For the substances listed here, it is true that they are pharmacologically active per se, but they do not necessarily have to be pharmacologically active in the quantity detected, as they were partly present in too small quantities (e.g. amphetamine, caffeine, MDMA). 

The potentially pharmacologically active substances on LSD felts analysed in 2020 are described below. 

NBOMe connections

NBOMe compounds are psychedelics and belong to the group of phenethylamines. Visual effects do occur, but are less prominent than with LSD. According to users, the effects of NBOMe compounds vary greatly from time to time. In contrast to LSD, felts with NBOMe compounds have a very bitter taste. NBOMe compounds have a more direct and faster effect if they are absorbed sublingually (under the tongue) through the mucous membranes. If the substances are taken orally, there may be a weaker effect and/or a delayed onset of action. This means that there is a risk that a high dose may be taken unintentionally. 

NBOMe compounds have been linked to some deaths in Europe. Various reports indicate that peripheral vasoconstriction may occur, requiring medical treatment. 

In 2020, an NBOMe compound was analysed (-0.2 %) on a felt declared as LSD (0.6 %). 

DOC (4-chloro-2,5-dimethoxy-4-chloroamphetamine) 

DOC is a very intensely effective psychedelic and leads to strong visual effects, euphoria and an intensified perception of music and movements. DOC can cause chest pain, vasoconstriction and nausea. Due to the late onset of action of DOC (up to 3 hours), there is a risk of overdosing, especially if confused with LSD. DOC has a very long duration of action of up to 20 hours. 

In 2020, DOC was analysed on a (0.6 %) felt declared as LSD (-0.6 %). 

LSD analogues 

Besides the long known and intensively researched LSD, there are various LSD analogues. Some of them have been known for a long time (e.g. ALD-52, ETH-LAD, AL-LAD, PRO-LAD etc.) and have been studied pharmacologically as well as psychopharmacologically, at least in part. Others are newer "creations" (e.g. the derivatives 1P-LSD, 1B-LSD, 1cP-LSD etc.) for which only few or no data are available. Certain LSD analogues may (still) be legally produced, traded and consumed in some countries, which is the main reason for their spread. 

Most LSD analogues naturally differ from LSD in their effect and/or potency (e.g. ETH-LAD, AL-LAD, LSZ etc.). In contrast, the so-called 1-acylated LSD compounds (e.g. 1P-LSD, 1B-LSD, ALD-52 etc.) are presumed, on the basis of pharmacological studies, to transform into LSD in the body (they function as so-called prodrugs) and thus have a comparable psychoactive effect to LSD. 

In the case of prodrugs of LSD and LSD analogues, it has not been conclusively clarified whether, in addition to their psychoactive effect, they can cause other pharmacological effects. How potent these prodrugs are in comparison to the resulting substance (e.g. 1P-LSD to LSD), and to what extent a delay in the onset of action occurs in each case, may depend on the substance and cannot be generalised. Thus, it is important to approach the dose/effect carefully in order to avoid overdoses. 

In 2020, a total of two felts declared as LSD analogues were analysed. Both felts unexpectedly contained the LSD analogue 1cP-LSD. 


The non-psychoactive iso-LSD is produced during the manufacture of LSD and/or during prolonged storage under non-destructive conditions (exclusion of light and oxygen); in each case by so-called isomerisation. Some users report that iso-LSD inhibits and/or otherwise influences the effect of LSD. However, there is no scientific evidence to support this hypothesis. Whether iso-LSD can produce non-psychoactive but otherwise pharmacologically relevant effects has not been conclusively clarified. Especially in higher doses, pharmacologically significant effects are conceivable. 

In 2020, iso-LSD was analysed in 26.9 % of the LSD felts analysed (-12.3 %); on average, the LSD felts contained 22.4 μg iso-LSD. 

Other substances 

In addition to the substances described above, small amounts of amphetamine, MDMA, DMT, 2C-B, cocaine, levamisole and caffeine were analysed on individual LSD felts. Since only small, hardly or not effective doses of these substances can be applied to LSD felts, risky interactions are very unlikely. It is assumed that it is mostly a matter of smear contamination (in minigrips already used with other substances) and that these substances were applied to the LSD felts unintentionally, and thus not as extenders. 


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