science

Isoergine

Isoergine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Isoergine rather than just read about it. In short: Isoergine, also known as isolysergic acid amide (iso-LSA or iso-LA-819), isolysergamide, or erginine, is a serotonergic psychedelic of the ergoline and lysergamide families related to ergine (lysergic acid amide; LSA) and lysergic acid diethylamide (LSD). It is the epimer of ergine inverted at the 8 position.

Key takeaways

Isoergine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Isoergine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Isoergine from memory before moving on to harder problems.

Reference excerpt

Isoergine, also known as isolysergic acid amide (iso-LSA or iso-LA-819), isolysergamide, or erginine, is a serotonergic psychedelic of the ergoline and lysergamide families related to ergine (lysergic acid amide; LSA) and lysergic acid diethylamide (LSD). It is the epimer of ergine inverted at the 8 position. Along with ergine and other ergolines, isoergine occurs naturally in morning glories. It is thought to be primarily responsible for the hallucinogenic effects of morning glory seeds.

Use and effects Isoergine occurs naturally in morning glory species, including Ipomoea tricolor (tlitliltzin), Ipomoea corymbosa (ololiuhqui), and Argyreia nervosa (Hawaiian baby woodrose). It has been found to constitute 8 to 35% of total alkaloid content relative to 5 to 58% for ergine. Albert Hofmann, the discoverer of LSD's psychedelic effects, tried 2 mg isoergine orally and experienced feelings of unreality, detachment from the outside world, feelings of mental emptiness, tiredness, and apathy, though no specific sensory distortions were mentioned. He described its effects as similar to those of ergine, which he had tested at doses of up to 2 mg. Subsequently Heim and colleagues assessed ergine at higher doses of 3 to 6 mg orally and observed toxic-like effects, while isoergine at 2 to 5 mg orally produced notable hallucinogenic effects. The psychedelic effects of isoergine observed in this study included some euphoria, synaesthesia, and altered time perception. However, although hallucinogenic, isoergine's effects have been described as not LSD-like. The presence of hallucinogenic effects of isoergine has been described as quite unusual for an isolysergamide derivative. It is thought that ergine and isoergine together may account for most or all of the effects of morning glory seeds, with ergine producing intoxication, sedation, and autonomic side effects and isoergine producing hallucinogenic effects. Conversely, other notable constituents, including elymoclavine, lysergol, and chanoclavine, produced no psychoactive or hallucinogenic effects in humans. Ergometrine, which is a minor constituent representing up to 8% of total alkaloids, is known to produce psychedelic effects only in higher amounts (2–10 mg) than those in typical doses of morning glory seeds and hence is thought to not contribute to the effects of the seeds either. Moreover, ergometrine is present in Ipomoea tricolor and Argyreia nervosa but not in Ipomoea corymbosa. Isoergine being responsible for the hallucinogenic effects of morning glory seeds is also supported by animal studies. According to Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved) however, both ergine and isoergine are "probably correctly dismissed" as not contributing to the effects of morning glory seeds. The poorly-stable lysergic acid hydroxyethylamides (LSHs) might alternatively be involved in the psychedelic effects of morning glory seeds per Shulgin.

Interactions

The interactions of isoergine and of morning glory seeds have been discussed.

Pharmacology

Pharmacodynamics Isoergine shows affinity for serotonin receptors labeled with serotonin or LSD in rat brain membranes. It has about 10- to 25-fold lower affinity for these receptors than serotonin or LSD and has the same affinity as ergine and iso-LSD (IC50Tooltip half-maximal inhibitory concentration = 100–200 nM for isoergine, 200 nM for ergine and iso-LSD, and 8–10 nM for LSD). No other receptor interaction data are available for isoergine as of 2020. However, computer-predicted receptor affinities are available for ergine/isoergine (stereochemistry not taken into account). The drug is said to have about 4.3% of LSD's antiserotonergic potency in vitro. It is 5- to 33-fold less potent than LSD in producing behavioral changes in the conditioned avoidance test in rodents.

Pharmacokinetics The pharmacokinetics of isoergine in rodents have been studied. Isoergine is much less lipophilic than LSD, with log P values of 0.95 and 2.95, respectively. This might influence its pharmacological properties, for instance reducing its blood–brain barrier permeability. However, isoergine showed a similar ratio of brain-to-plasma levels as LSD in rodents.

Chemistry

Derivatives Derivatives of isoergine include isolysergic acid diethylamide (iso-LSD), isolysergic acid hydroxyethylamide (iso-LSH), and ergometrinine (isoergometrine; isolysergic acid propanolamide), among others. With the apparent exception of isoergine, isolysergamides, such as iso-LSD, have been found to be inactive as psychedelics in humans.

History Isoergine was first identified by Sidney Smith and Geoffrey Timmis in 1936 via hydrolysis of ergot alkaloids. This followed the identification of ergine in the same way in 1932. Isoergine was first synthesized by Albert Hofmann and colleagues by 1949. Subsequently, it was isolated by Hofmann and colleagues in morning glory seeds in 1960. The psychoactive effects of isoergine were first described by Hofmann in 1963. Heim and colleagues more clearly substantiated the hallucinogenic effects of isoergine and its role in producing the psychedelic effects of morning glory seeds in 1968.

Society and culture

Legal status

Canada Isoergine is not a controlled substance in Canada as of 2025.

United States Ergine is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.

See also Ergine (lysergic acid amide; LSA; lysergamide) Aztec use of entheogens § Ololiuqui and Tlitliltzin Morning glory § Chemistry and ethnobotany List of entheogens List of psychoactive plants

References

External links Isoergine - Isomer Design LSD-25 (Discusses Isoergine) - TiHKAL - Erowid LSD-25 (Discusses Isoergine) - TiHKAL - Isomer Design

Illustrations

Worked examples

Example 1 — a first encounter with Isoergine

Start with the simplest possible case. Write down what Isoergine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Isoergine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Isoergine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Isoergine

In research: Isoergine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Isoergine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Isoergine is common in secondary-school and first-year university syllabi. It links to neighbouring topics 5-HT2A agonists, Alkaloids found in fungi, Drugs not assigned an ATC code, so understanding it makes those chapters shorter.
In everyday life: Look for Isoergine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Isoergine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Isoergine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Isoergine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Isoergine in simple terms?

Why does Isoergine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Isoergine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Isoergine.