Methysergide is capable of producing a state of mind like LSD, judging by human reports and its effect on the fish surfacing reaction, though methysergide is less potent than LSD. Another interesting fact, according to Abramson, is that a methysergide trip is slightly longer-lasting - by 2-3 hours - than a typical LSD reaction. Like LSD, tolerance develops quickly to methysergide so that patients taking it for headaches usually do not report significant side effects, except for the first few times they take it. A trip on methysergide produces mental disorientation, insomnia, giddiness, a dreamy state, distortion of body image and apprehension. Methysergide, psilocybin, and LSD were compared in the same 4 patients. One of them felt that the experience was about half as severe as a LSD reaction, but in another subject, 3.5 milligrams of methysergide produced a full blown, typical LSD reaction equal to 25 micrograms of LSD.The table below lists the threshold dose of methysergide, felt to be equivalent to a 25 ug dose of LSD.
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| From other human hallucinogens, LSD derivatives |
Methysergide is about as potent as psilocybin. Human subjects responded to an average threshold dose of 3.4 mg psilocybin, and an average threshold dose of 4.3 mg or more of methysergide. When the the effects of LSD, methysergide, and psilocybin were compared in humans, psilocybin was 135X less potent than LSD, and methysergide was 170X less potent than LSD. A diminishment of potency is also seen in fish. Methysergide produces the LSD fish surfacing reaction, but it is 250X less potent than LSD.
Methysergide is also referred to UML-491, or 1-methyl-d-lysergic acid-butanolamide. Methysergide is prescribed for migraine headaches and it is sold commercially as Sansert or Deseril. A 2 mg dose of methysergide is effective for reducing migraine headaches; Sansert comes in 2 mg pills. The psychotomimetic dose of methysergide was 4.3 mg in human volunteers (above), that would be 3 pills of Sansert. Since the therapeutic dose of Sansert is about half the psychotomimetic dose, methysergide doesn't have much reputation for causing far-out trips. Mental changes caused by methysergide would be expected to be strongest at the onset of treatment, before the development of tolerance. When side effects appeared it was frequently noted that the symptoms abated or remained mild if patients could tolerate them for several days.
Reference
Abramson, H. A. and A. Rolo 1965. Lysergic acid diethylamide (LSD-25). 38. comparison with action of methysergide and psilocybin on test subjects. J. Asthma Res. 3, 81-96. DOI:10.3109/02770906509106904
