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Introduction: why people compare 1P-LSD to LSD

Anyone delving into psychedelics will soon encounter the term “LSD analogues,” such as 1P-LSD. Online discussions often revolve around the question of whether 1P-LSD “works differently” than classic LSD-25, or whether the body first converts 1P-LSD into LSD. This is not a purely theoretical discussion: it touches upon expectations regarding duration, onset, intensity, interpretation of experiences, and the way people assess risks.

In this article, we outline in a calm and informative manner what the scientific literature currently states regarding the conversion of 1P-LSD to LSD. We make a clear distinction between research findings, possible explanations, and what people sometimes report in anecdotal accounts. This is not individual medical advice and is not an encouragement to use substances.

What exactly is 1P-LSD?

1P-LSD (full name: 1-propionyl-LSD) is often described as a “prodrug” of LSD. A prodrug is a substance that is (partially) converted in the body into another active substance. The idea is that 1P-LSD itself may be less or differently active, whereas the body releases LSD after ingestion, which subsequently explains the majority of the psychoactive effects.

It is important to note that in chemistry, “analog” simply means that the molecular structure closely resembles that of another substance, with a minor modification. Such a modification may sometimes make little difference, but it can also influence factors such as the rate of absorption, breakdown, and how strongly a substance binds to receptors. Therefore, it is logical that there is a great deal of interest in exactly what happens in the body.

The prodrug mechanism: what does research show?

The core question is: is 1P-LSD converted to LSD in the body, and if so, how quickly and to what extent? Various studies (including publications from around 2019 and 2020 that are frequently referenced in discussions) support the view that 1P-LSD and several related substances can indeed function as prodrugs. Animal models have described that enzymes can “deacylate” 1P-LSD relatively quickly, producing LSD that can subsequently be measured in the blood.

That does not automatically mean that everything proceeds identically in everyone. Animal research can provide clues about mechanisms, but the translation to humans has limitations. At the same time, the prodrug idea here is not merely speculation: it aligns with measurement data in biological samples and with pharmacokinetic observations, which we will return to below.

In practice, it is therefore reasonable to state that the literature supports the prodrug mechanism, with the nuance that the exact rate of conversion and variation between individuals have not always been fully mapped.

Potency and dosage: why “molecular correction” is relevant

A much-discussed point is potency. If 1P-LSD is a prodrug that is (partially) converted into LSD, then molecular mass plays a role. 1P-LSD is heavier than LSD due to the extra chemical group. Consequently, for example, 100 micrograms of 1P-LSD contains less “LSD equivalent” than 100 micrograms of LSD, simply because part of the weight is contained in that extra group.

A number of preclinical studies have reported that 1P-LSD exhibits an LSD-like profile in behavioral models. When researchers correct for the difference in molar mass (the so-called molecular correction), the relative potency often becomes closer. In online discussions, for example, it is stated that approximately 117 micrograms of 1P-LSD could roughly correspond to 100 micrograms of LSD in terms of molarity. These types of calculations are mathematically logical, but they remain approximations: true effects also depend on metabolism, absorption, and individual sensitivity.

Therefore, it is more sensible to think in terms of margins of uncertainty than in exact equivalent doses. Even with the same substance, the experience can vary greatly from person to person and setting to setting.

Pharmacokinetics in humans: what is measured in blood?

Most relevant to the question “does 1P-LSD convert to LSD in the body?” are studies in which blood levels are measured after ingestion. A human study (around 2020, frequently cited in abstracts) described that 1P-LSD can be detected in serum after oral ingestion, but that the concentration drops relatively quickly, while LSD itself remains detectable for longer. That pattern fits a scenario in which 1P-LSD is converted to LSD: you see 1P-LSD appear first, and then LSD dominates in the blood.

It is important to note that nuance here: “detectable” does not automatically mean “responsible for all effects”. It is also possible that both 1P-LSD and LSD contribute to varying degrees. However, the fact that LSD persists longer and 1P-LSD wears off more quickly does support the idea that metabolism plays an important role.

Why some people report a different turnout

In anecdotal accounts, people sometimes report that 1P-LSD has a slightly slower onset than LSD-25, while the subsequent peak experience feels comparable. This cannot be definitively proven based on isolated experiences, but it is a plausible observation if an extra step is indeed required before LSD becomes available in the body. Conversion can take time, and small differences in the rate of absorption and breakdown can be subjectively noticeable.

At the same time, caution is needed when interpreting this type of statement. The perceived “uptake” is also strongly linked to set and setting, expectation, previous experiences, and practical factors such as meals, sleep, stress, and environment. Furthermore, the composition and dosage of blotters or other carriers in the illegal market can be uncertain, which obscures comparisons.

What does this mean for therapy, guidance, and safety?

Although this article focuses primarily on metabolism, context is important: some people approach LSD-like substances with a therapeutic intention. A good therapist (or counselor in a non-medical context) will typically look not only at the substance, but especially at preparation, intention, safety, aftercare, and integration. Precisely because the experience can be intense and because individual reactions vary, counseling is not something that can be reduced to “the substance is the same, so it is the same.”.

In addition, it is important to remain factual regarding the state of affairs surrounding MDMA: MDMA sessions can currently only be discussed within scientific research or in practice via harm reduction. In general, for psychedelic sessions, scientific research and clinical protocols are still under development, and scientific results do not mean that it is suitable or safe for everyone.

Harm reduction is not about glorifying substances, but about minimizing risks wherever possible. Consider attention to mental state, contraindications you might want to discuss with a professional, dosage uncertainty, setting, fasting support, and recognizing signs that things are not going well. These types of principles are substance-independent.

Avoiding legal claims: what we can and cannot say

It is sometimes claimed online that analogues are “legal” and therefore “therapeutically usable”. However, legal status can change and depends on legislation, interpretation, and enforcement. Moreover, legality says nothing about safety or suitability. Therefore, it is wise not to draw firm legal conclusions based on forum claims or outdated information.

What we can say is this: the literature provides indications that 1P-LSD can behave as a prodrug of LSD, and that explains why effects are often experienced as LSD-like. However, legal status, product quality, and the context of use remain separate subjects with their own uncertainties.

In-depth: what does the source this question often refers back to say?

The discussion that many people read about this topic refers to multiple lines of inquiry: animal research, human measurement data, and practical experience. Anyone wishing to view the original Q&A can do so via this source page about LSD analogues and LSD. Please bear in mind that a forum context is usually a mix of literature references and interpretations, and that not every claim is equally verifiable.

Conclusion

The available scientific literature supports the idea that 1P-LSD can be converted to LSD in the body, and that this is a major explanation for the often LSD-like effects. Human pharmacokinetic findings fit this picture, while differences in onset that people sometimes report are plausible but cannot be unequivocally proven from anecdotal evidence alone. Those approaching psychedelics with a therapeutic intent would do well not to focus solely on chemistry, but also on preparation, guidance, and harm reduction.

If you would like to explore guided sessions in a harm-reduction context, you can find more information and express your interest via sign up for an MDMA session. In addition, it should be noted that MDMA sessions can currently only take place within scientific research or in practice via harm reduction, and that the provision of information does not replace a personal medical assessment.