What is 1Fe-LSD? – One of many LSD derivatives

In the research chemical market, there are numerous legal LSD derivatives, whose names often consist of confusing combinations of numbers and letters.

While popular LSD analogs such as 1V-LSD, 1cP-LSD, or 1P-LSD have been banned for some time, reports on 1BP-LSD and 1Fe-LSD are currently circulating in the psychonautic community.

This article addresses the question of what 1Fe-LSD actually is from a chemical perspective, how this substance works, and what its current legal status is.

Happy reading!

Note: 1Fe-LSD is not intended for human consumption. All described content is based on scientific sources or subjective experience reports and should not be understood as instructions or recommendations.

The abbreviation LSD stands for "Lysergic Acid Diethylamide", which is a simplified form of the full chemical name. LSD, often colloquially referred to as "Acid", is a semi-synthetic hallucinogen developed by Albert Hofmann and is one of the most potent known drugs.

1-(Ferrocenecarbonyl)-LSD or in short 1Fe-LSD is a modification of classic LSD-25, which is metabolized in the body and can cause psychedelic effects such as pseudo-hallucinations and perceptual disturbances. Due to the addition of the iron compound ferrocene, this LSD analog is currently legal (01/2026), as it does not fall under the regulations of the NpSG (New Psychoactive Substances Act).

Fun Fact: Ferrocene is very likely responsible for the noticeable orange coloring of 1Fe-LSD blotters and pills.

1Fe-LSD, 1BP-LSD and all their now banned predecessors have one thing in common: they are all research chemicals not intended for human consumption.

Since they do not have marketing authorization, these substances may also not be used in therapeutic settings.

The substance 1Fe-LSD, which can be acquired in the form of pills or as impregnated paper pieces with a typical orange coloration, is intended exclusively for research.

Pharmacology has so far provided little concrete knowledge about the specific effects of 1Fe-LSD. However, comparison with earlier LSD derivatives such as 1D-LSD or 1B-LSD suggests that 1Fe-LSD could also be a so-called prodrug to LSD.

An LSD prodrug is metabolized in the body into the base substance LSD, leading to the typical LSD intoxication known as a "trip".

At the biochemical level, it can be assumed that 1Fe-LSD mediates its psychedelic effects through an agonistic interaction with the so-called 5-HT2A receptors in the brain. These receptors belong to the serotonin system and are significantly involved in the regulation of mood, emotional processing, perception, and the sleep-wake cycle. Furthermore, they play a central role in neuroplasticity.

By binding to these receptors, neuronal signal transmission in the brain changes. The result is an altered way of information processing, often described as more intense, emotionally condensed, or cognitively expanded, which creates the "out-of-the-norm experience" typical of psychedelic substances.

As profound as these subjective effects may seem, the underlying mechanism remains comparatively sober: LSD and related derivatives modulate the serotonin system, thus interfering with fundamental neurobiological processes that shape perception, emotions, and cognitive flexibility.

New research chemicals are constantly appearing on the market, including substances that act analogously to LSD because they are so-called prodrugs.

This cat-and-mouse game between chemical laboratories and legislators has a very specific background: the New Psychoactive Substances Act (NpSG).

The so-called NpSG was introduced in Germany in 2016 as a tool of drug policy to be able to react more quickly to novel legal highs. Through amendments and updated regulations, more and more substances are being covered and thus banned. For this reason, manufacturers are dedicating themselves to the development of ever new LSD derivatives that can legally re-enter the market through clever structural modifications.

With the entry into force of the sixth ordinance amending the annex to the NpSG, which was adopted on November 21, 2025, 1S-LSD and 1SB-LSD became illegal in December 2025.

However, soon after this ban, two novel LSD alternatives not affected by the ban came onto the market: 1BP-LSD and 1Fe-LSD. How long these LSD derivatives will remain legal is currently not foreseeable; a ban could be initiated at any time.

1Fe-LSD joins a long line of LSD derivatives created through targeted chemical modifications to continue to be researched despite strict legislation.

The combination of a classic LSD backbone and the ferrocene side group makes 1Fe-LSD particularly interesting from a chemical perspective and at the same time explains why the substance, as it stands, does not fall under the New Psychoactive Substances Act.

At the same time, a look at the pharmacology and mechanism of action shows that 1Fe-LSD and 1BP-LSD are conceptually strongly based on earlier LSD prodrugs. Even though reliable scientific data is still lacking, structural comparisons and biochemical considerations suggest that similar processes in the serotonin system could be triggered as with already known LSD derivatives.

It should not be overlooked that 1Fe-LSD is a research chemical that is neither intended for human consumption nor approved for therapeutic use. The legal grey area in which such substances operate remains dynamic and can change at any time.

1Fe-LSD and 1BP-LSD thus exemplify the tension between scientific interest, regulatory control, and the ongoing development of new psychoactive substances. How long these derivatives will remain available and what role they will play in future research remains to be seen.

• Tanaka R., Kawamura M., Mizutani S., Kikura-Hanajiri R. (2023). Identification of LSD analogs, 1cP-AL-LAD, 1cP-MIPLA, 1V-LSD and LSZ in sheet products. Forensic Toxicol. 2023 Jul; 41(2): 294-303. doi: 10.1007/s11419-023-00661-1.

• Vargas M. V., Dunlap L. E. et al. (2023). Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors. Science. 2023 Feb 17;379(6633): 700-706. doi: 10.1126/science.adf0435.

• Brandt S. D., Kavanagh P. V., Gare S., Elliott S. P., Stratford A., Halberstadt A. L. (2025). Analytical and Pharmacological Characterization of 1-(Furan-2-Carbonyl)-LSD (1F-LSD) and Comparison With 1-(Thiophene-2-Carbonyl)-LSD (1T-LSD). Drug Test Analy. 2025 Aug;17(8): 1283-1293. doi: 10.1002/dta.3829.