LSA

LSA, also known as ergine or lysergic acid amide, is a naturally occurring ergot alkaloid found in several plants of the Convolvulaceae family. It is structurally related to LSD, but its carboxamide group is unsubstituted. Human reports describe psychoactive effects alongside nausea and other physical reactions. A 2025 systematic review found that the evidence base remains small and that severe adverse outcomes have been documented.

Chemistry and natural occurrence

LSA is the primary amide of lysergic acid. It shares the ergoline framework with LSD, but LSD carries two ethyl groups on the amide nitrogen. LSA has also been detected in seeds from morning glory species and Hawaiian baby woodrose, together with other ergot alkaloids. The amount and composition vary between plant species and individual batches.

LSA should not be confused with LAE-32, or lysergic acid monoethylamide. The names have occasionally been confused in older discussions, but they refer to different chemical structures.

Pharmacology

LSA is generally considered a serotonergic ergoline, but its receptor pharmacology is less thoroughly characterised than that of LSD. Available in-vitro comparisons indicate lower affinity at several serotonin receptor subtypes than LSD. This difference may contribute to the distinct profile reported in humans, although the mechanism is not fully established.

Human effects and adverse outcomes

A 2025 systematic review identified 17 studies containing original human data. Reported effects included euphoria, perceptual changes and hallucinations, but nausea, anxiety and other unpleasant physical reactions were also common. The review included reports of hypertension, psychosis and hospitalisation, showing that LSA exposure is not necessarily benign (Castro and colleagues, 2025).

Some reports describe the use of LSA-containing plant preparations in connection with cluster headaches. The evidence is based largely on self-reported outcomes and uncontrolled observations. It does not establish clinical efficacy or a standardised medical application.

Variability and toxicology

Interpreting LSA reports is difficult because plant material contains mixtures of ergot alkaloids, rather than a uniform preparation of purified ergine. Concentrations can vary substantially, and other constituents may contribute to the effects or adverse reactions. This makes it difficult to compare cases or establish a reliable relationship between exposure and clinical outcome.

The 2025 review concluded that the available human literature is insufficient to define a clear safety profile. Long-term effects and dependence potential also remain poorly characterised.

Related lysergamides

LSA is related to LAE-32, LSH and LSD. It is the primary amide of lysergic acid, whereas LAE-32 is the monoethylamide and LSD is the diethylamide.