1Fe-LSD and 1BP-LSD: Differences & Similarities of the two LSD Alternatives

1Fe-LSD and 1BP-LSD belong to a current generation of LSD derivatives that are of particular interest in the context of jurisprudence, research, and within the psychonaut community.

Like many of their predecessors, these research chemicals are based on the well-known lysergamide basic structure but differ due to specific chemical modifications of their side chains. These structural subtleties could influence both their pharmacological properties and their legal classification.

Initial experience reports and theoretical conclusions suggest that both the course of action and metabolism could differ in nuances from classic LSD-25 and earlier derivatives.

The following article takes a closer look at these aspects and highlights both similarities and differences between 1BP-LSD and 1Fe-LSD to enable the most objective classification possible.

Enjoy reading the following blog post!

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

With the entry into force of the New Psychoactive Substances Act (NpSG) in 2016, German drug policy pursued the aim of countering the constant emergence of new research chemicals more effectively. Since then, further substances and their structural variants have been continuously added to the respective prohibition catalogs by regulation.

In practical implementation, however, this approach by the Federal Ministry of Health has increasingly proven to be an inscrutable game of cat and mouse between the legislator and the psychonaut scene.

Numerous LSD derivatives have been banned in recent years, including 1D-LSD, 1V-LSD, 1T-LSD, 1cP-LSD and 1SB-LSD [1]. Almost every ban was accompanied by the timely emergence of a new, legally still permissible variant that again allowed the handling of LSD-related substances outside of criminal consequences. This interplay has characterized the situation for about a decade now.

The abbreviation 1BP-LSD stands for 1-(3-(tetramethyldioxaborolane)propionyl)-LSD. Behind this complicated-sounding name lies a modern LSD analogue that first attracted the attention of the research community at the end of 2025.

As with many previously available LSD derivatives, 1BP-LSD also has an additional side chain coupled to the basic molecule via an amide bond on the indole ring.

The molecule 1BP-LSD contains a side group with a boron-containing heterocycle at the indole nitrogen. This means that a boron atom is present in the side chain.

The abbreviation 1Fe-LSD refers to the research chemical 1-(Ferrocenecarbonyl)-LSD, an LSD prodrug that was introduced in December 2025 roughly at the same time as 1BP-LSD as a successor to already banned LSD derivatives.

As with the previous and now illegal LSD alternatives, 1Fe-LSD also has an additional side chain bound to the basic molecule via an amide bond. The special feature of 1Fe-LSD is the attachment of the metallocene ferrocene to the indole ring.

Nice to know: The organometallic, iron-containing compound ferrocene is considered to be the cause of the striking orange color of the 1Fe-LSD pellets, blotters and drops.

The effect of legal LSD products like 1Fe-LSD, 1BP-LSD, 1D-LSD, or 1S-LSD fundamentally resembles the effects caused by the illegal substance lysergic acid diethylamide (LSD).

Legal LSD alternatives are specifically designed to act as so-called prodrugs in the human body. Their actual psychoactive effect therefore only unfolds after undergoing certain metabolic processes.
Specifically, the respective LSD analog is gradually converted into classic LSD in the organism, and as a result, produces comparable effects.

Additional molecular attachments in the side chains, such as the additional boron atom in 1BP-LSD or the ferrocene in 1Fe-LSD, must first be cleaved off and can lead to a slightly delayed onset of action compared to LSD-25.

After completed metabolism, these derivatives influence specific receptor systems in the brain. A central role is played by the activation of the 5-HT2A serotonin receptor, which is considered crucial for the hallucinogenic effect and, according to experience reports, can manifest as an expanded consciousness and a psychedelically altered perception [2].
Under unfavorable circumstances, subjectively distressing, temporary experiences are also possible, which users often refer to as "bad trips."

Important: Due to the relative novelty of both substances, official scientific data from the fields of chemistry and toxicology are currently still lacking.

Due to the added groups in the side chains, the molar mass of both LSD derivatives 1Fe-LSD and 1BP-LSD changes compared to conventional LSD-25.

This has direct implications for the dosage that researchers should consider:

The LSD-25 molecule has a molar mass of 323.4 g/mol.

The 1BP-LSD molecule, due to its side group with the boron-containing heterocycle, is significantly heavier with a molar mass of 609.6 g/mol. To achieve the effect of a 100 µg dose of LSD-25, theoretically about 188 µg of 1BP-LSD would have to be used. For researchers, this means that the dose of 1BP-LSD must be increased by approximately 1.9 times to achieve a roughly similar effect to LSD.

1Fe-LSD has a molar mass of 535.5 g/mol, making it slightly lighter than 1BP-LSD, but still heavier than LSD-25 due to the ferrocene attached as a side chain. To achieve the effect of a 100 µg dose of LSD-25, approximately 165 µg of 1Fe-LSD would be necessary. A psychonaut would therefore have to use 1.65 times the dose of 1Fe-LSD to achieve an effect comparable to regular LSD.

1Fe-LSD and 1BP-LSD are the two currently legally available LSD derivatives on the German market.

Both LSD alternatives were introduced at roughly the same time, after legislators decided to ban 1S-LSD and 1SB-LSD in November 2025. This amendment to the NpSG made the legal distribution of previously legal LSD versions impossible as of December 2025.

Both 1Fe-LSD and 1BP-LSD are currently (01/2026) legally available in Germany, as they are not covered by the New Psychoactive Substances Act (NpSG), the Medicines Act, or the Narcotics Act (BtMG) [3, 4].

However, legal problems could still arise if LSD derivatives are detected in traffic or in a professional environment.

The development of research chemicals such as 1T-LSD, 1P-LSD, 1BP-LSD, or 1Fe-LSD can be understood as a direct consequence of drug policy regulations [5].

Their production follows the so-called "legal-by-design" approach: the focus is not on pharmacological criteria or safety issues, but primarily on the goal of creating a substance that falls outside existing prohibition regulations.

In order to continuously offer new, legally unclassified substances, the basic molecular scaffold is specifically modified without significantly altering the original psychoactive effect. This exact approach also enabled specialized laboratories to develop 1BP-LSD and 1Fe-LSD.

New LSD derivatives like 1BP-LSD or 1Fe-LSD constantly open up possibilities for psychonautics enthusiasts and other researchers to explore psychedelic effects with reliable dosages without having to resort to a prohibited substance and thus risk criminal prosecution.

• [1] 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.

• [2] Vargas M. V., Dunlap L. E., Dong C., 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.

• [3] https://www.gesetze-im-internet.de/npsg/

• [4] https://www.gesetze-im-internet.de/btmg_1981/

• [5] 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.