MBL-61, or MOB-61, also known as 1-methyl-2-bromo-LSD, is a serotonin receptor modulator of the lysergamide family related to lysergic acid diethylamide (LSD). https://www.erowid.org/library/books_online/tihkal/tihkal26.shtml "BOL-148. 2-Bromo-N,N-diethyllysergamide. This synthetic ergot derivative, along with its 1-methyl homologue MBL-61 (mentioned below) should be used as powerful tools for studying the mechanism of action of LSD in the human animal. It does not have LSD-like effects in man. At 6 to 10 milligrams orally, there are some mental changes noted. But in another study, 20 milligrams was administered a day to a subject for 7 days, and there were no reported effects. And yet it is as potent a serotonin agonist as is LSD. How can serotonin be argued as a neurotransmitter that is a major player in explaining the action of psychedelic drugs, when this compound is nearly without activity. [...] MBL-61. 2-Bromo-N,N-diethyl-1-methyllysergamide. This is the compound BOL-148 (mentioned above) with a methyl group attached to the 1-position of the indole ring (LSD has a hydrogen there). This would be an even more tantalizing challenge to the serotonin theory for central activity of the psychedelics, in that it is without any activity in man at an oral dose of 14 milligrams (similar to the inactivity of the BOL-61 compound, but it is some five times more potent as a serotonin agonist. With it, as with the iodinated analogue MIL, there are many examples of the compromising of scientific integrity in the quest for funds and recognition. Both compounds are as effective as LSD itself in displacing labelled LSD that is bound to the post-synaptic serotonin receptor sites in animal brains. But neither of them show any LSD-like activity. But both have been labelled with 11C or 122I to give positron emitting forms that can be administered to man and localized in a positron emission tomography instrument (a PET scanner). It is the 1-methyl derivative of 2-bromo-LSD (BOL-148). Extensive metabolism of other 1-methylated lysergamides to their secondary amine derivatives, for instance methysergide (1-methylmethylergometrine) conversion into methylergometrine, has been observed. Similarly to the case of 2-bromo-LSD, MBL-61 was inactive as a psychedelic in humans at doses of up to 10 to 14mg orally. However, whereas 2-bromo-LSD can reportedly still produce some hallucinogenic effects at high doses, such effects are said to be completely lost in the case of MBL-61. In any case, both drugs are still potent serotonin receptor modulators like LSD, with MBL-61 having 5.3-fold the antiserotonergic activity of LSD in vitro and the highest degree of antiserotonergic activity of any other assessed lysergamide. MBL-61 was first described in the scientific literature by Albert Hofmann and colleagues in 1957.
See also Substituted lysergamide BOL-148 (2-bromo-LSD) 1P-BOL-148 1-Methyl-2-iodo-LSD (MIL) 2-Iodo-LSD MLD-41 (1-methyl-LSD) Methysergide
References
External links 2-Bromo-1-methyl-LSD (MBL-61) - Isomer Design LSD-25 (Discusses MBL-61) - TiHKAL - Erowid LSD-25 (Discusses MBL-61) - TiHKAL - Isomer Design