Yellow Adonis (Adonis vernalis): Uses, Safety, and What the Evidence Shows

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The short answer is that this is not a plant to experiment with at home. Yellow adonis — Adonis vernalis, also called spring pheasant’s eye — contains cardiac glycosides, the same family of compounds that make foxglove both a life-saving medicine and a lethal poison. European medicine used it for over a century as a heart stimulant, and that history is real. But the amount that steadies a failing heart and the amount that stops one sit uncomfortably close together, and the plant itself does not come with a label telling you which you have.

This page covers what the plant actually is, what it was historically used for, what modern research does and does not support, and where the safety lines fall. If you are here because you or someone you know may have swallowed part of this plant, skip to the poisoning section below — or call Poison Control at 1-800-222-1222 now.

What Yellow Adonis Is

Yellow adonis is a perennial in the Ranunculaceae (buttercup) family, the same family as pasque flower and buttercups. It grows roughly 10 to 45 cm tall, with finely divided feathery leaves and large, bright yellow flowers that open in early spring — sometimes with up to twenty petals [Shang et al., Frontiers in Pharmacology, 2019]. It favors dry, calcium-rich grassland and is distributed across a long band of Eurasia, from Spain east into Russia.

Other names you will see include pheasant’s eye, spring pheasant’s eye, and false hellebore. The medicinal material in European practice was Adonidis herba — the dried aerial parts of the flowering plant, not the roots, which contain little or no active compound [EMEA summary report on Adonis vernalis, 1998].

One practical note for US readers: this plant is not native to North America and is uncommon here. If you have encountered a yellow spring flower in a US garden or field, it is far more likely to be a buttercup, celandine, or marsh marigold. Do not assume an identification. Both the leaves and roots of Adonis species are documented as poisonous to humans and livestock [Shang et al., 2019].

The Compounds That Make It Active — and Dangerous

The pharmacology here is well characterized, and it explains everything else on this page. The aerial parts contain cardenolides — cardiac glycosides that inhibit the Na⁺/K⁺-ATPase pump in heart muscle cells. Blocking that pump raises intracellular calcium, which makes each contraction stronger. That is the same mechanism digoxin uses [EMEA, 1998].

Around 30 cardenolides have been identified in this species. By proportion, the dominant ones are adonitoxin (roughly 15–20% of total cardenolides), k-strophanthin-β (15–18%), k-strophanthoside (5–8%), and cymarin (5–6%) [EMEA, 1998]. Across the wider Adonis genus, researchers have cataloged more than 120 compounds in total, of which 54 are cardiac glycosides, alongside flavones, carotenoids, and coumarins [Shang et al., 2019].

Here is the number that matters most. The total cardenolide content of the dried aerial parts ranges from 0.2% to 1.0% of dry weight [EMEA, 1998]. That is a fivefold spread between a weak batch and a strong one, driven by where the plant grew, when it was harvested, and how it was dried. Two visually identical spoonfuls of dried herb can differ in potency by a factor of five — and there is no way to tell by looking.

How Yellow Adonis Has Been Used Historically

The plant entered formal European medicine in 1879, when a Russian physician introduced alcoholic extracts as a cardiac stimulant. In 1898 the neurologist Vladimir Bekhterev proposed combining it with bromide salts for mild heart failure and related complaints. Through the twentieth century, ethanolic extracts of the aerial parts were prepared as cardiac agents in the former Soviet Union and Germany, and the plant appears in the German Homoeopathic Pharmacopoeia [Shang et al., 2019]. In Siberia, aqueous preparations were traditionally used for edema and kidney complaints.

Two things are worth separating here. Standardized pharmaceutical preparations were made from adonis — powder adjusted to a fixed cymarin-equivalent activity, dispensed under medical supervision [EMEA, 1998]. That is a manufacturing process with assay equipment behind it. It is not the same activity as steeping dried flowers in a kitchen, and the history of the former does not license the latter.

What the Research Actually Shows

Honest summary: the cardiotonic activity is real and mechanistically well understood, but the modern clinical evidence base in humans is thin to the point of being unusable for treatment decisions. Shang and colleagues, reviewing the entire genus, note that only a small number of in vitro and in vivo studies of cardioprotective effects are available, and that the clinical studies that do exist are roughly fifty years old and no longer considered valid [Shang et al., 2019]. The EMEA committee reached a similar conclusion from the other direction: it could not establish a complete pharmacological and toxicological profile from the available information [EMEA, 1998].

One older comparison is often repeated and deserves a careful reading. Turova and Sapozhnikova reported in 1989 that adonis is as effective as digitalis in heart failure with conduction disturbance, and that its effects are not cumulative [cited in Shang et al., 2019]. The non-accumulation point has some mechanistic support — the main adonis glycosides are relatively polar and are excreted predominantly in urine [EMEA, 1998] — but this is a single secondary citation from a 1989 source, not a finding you should treat as settled. It also does not make the plant safer to self-administer: a compound that clears quickly can still cause a dangerous arrhythmia on the way through.

Evidence Summary

Claimed use	Best available evidence	Evidence grade
Increases force of heart contraction	Well-established Na⁺/K⁺-ATPase mechanism; animal and isolated-tissue studies	Mechanism well established
Treatment for heart failure	Historical clinical use in USSR/Germany; trials are ~50 years old and not considered valid	Insufficient modern evidence
Antiarrhythmic effect	Animal electrophysiology studies, mostly in related Adonis species	Animal only
Diuretic effect	Traditional use plus animal data; no controlled human trials	Traditional / animal only
Coronary artery dilation / angina	Asserted in older herbal literature; no controlled human data located	Insufficient evidence
Mild sedative effect	Historical combination use with bromides; no isolated human data	Traditional only
Safe substitute for foxglove	Rests on a single 1989 secondary source; not independently confirmed	Insufficient evidence

Why the Dose Margin Is the Central Problem

Every cardiac glycoside has a narrow therapeutic index. For this class as a general rule, toxic effects appear at doses exceeding the therapeutic dose by a factor of only 1.5 to 3 [EMEA, 1998]. Put plainly: roughly double the helpful amount can be the harmful amount.

Now combine that with the fivefold variability in the raw plant. If your dried herb happens to be a strong batch rather than a weak one, you have already crossed the margin without changing anything about how you measured. This is why the plant’s historical use was always tied to standardized, assayed preparations and physician supervision — the standardization was doing the safety work, not the plant.

This is also why no home-preparation instructions appear on this page. There is no way to make a cardiac glycoside infusion safe in a domestic kitchen, and older herbal texts that print gram-and-spoonful recipes for this plant were written before that was well understood. Absorption adds a further layer of unpredictability: the more polar strophanthin-type cardenolides are absorbed at under 10% from the gut, while the more hydrophobic cymarin has been reported at up to 47% in humans [EMEA, 1998]. The proportion of each varies between batches too.

Side Effects and Signs of Cardiac Glycoside Poisoning

Documented human poisonings from adonis preparations have occurred during therapy, at doses above the intended one. The earliest signs of oral overdose were gastrointestinal: nausea, vomiting, stomach upset, and diarrhea [EMEA, 1998]. Those symptoms are easy to dismiss as something you ate, which is part of what makes this class of poisoning dangerous.

Cardiac glycoside overdose more broadly can affect the heart, gut, eyes, and nervous system. Reported effects include blurred vision and colored halos around lights, nausea and vomiting, abdominal pain, loss of appetite, an irregular or abnormally slow heartbeat, weakness and fainting, confusion, drowsiness, headache, and in severe cases shock. Outcomes can be poor when heart rhythm is disturbed, and deaths do occur, particularly in young children and older adults [MedlinePlus, National Library of Medicine, 2025].

Red flags — get help immediately If someone has swallowed any part of this plant or a preparation made from it, do not wait for symptoms. In the United States, call Poison Control at 1-800-222-1222 (free, 24/7) or call 911 for a medical emergency. Call 911 rather than waiting if there is: a slow, racing, or irregular pulse; fainting or near-fainting; chest pain; confusion; visual changes such as yellow-green halos; or persistent vomiting after ingestion. Do not induce vomiting unless Poison Control or a doctor tells you to. Take the plant material or product container with you to the emergency room if you can — identifying the exact species changes treatment.

Drug Interactions

This is the section that matters most if you already take medication. Because yellow adonis acts on the heart the same way digoxin does, the interaction risks are substantial and clinically plausible rather than theoretical [Therapeutic Research Center via WebMD, 2026].

Medication or class	Why it matters
Digoxin (Lanoxin) and other cardiac glycosides	Additive effect on the same target. Do not combine — this stacks two sources of the same toxicity.
Diuretics (“water pills”)	Lower potassium, which increases the risk of serious cardiac side effects from glycosides.
Corticosteroids	Can also lower potassium, with the same compounding risk.
Stimulant laxatives	Diarrhea and potassium loss raise cardiac risk.
Macrolide and tetracycline antibiotics	May increase how much of the plant’s active compounds the body absorbs.
Quinine	May increase how long the active compounds remain in the body.

Low blood potassium is the thread running through most of these. If you take a diuretic or have any reason to run low on potassium, the risk from a cardiac glycoside rises accordingly [Therapeutic Research Center via WebMD, 2026]. Talk to your doctor or pharmacist before combining any herbal product with heart medication — pharmacists are often the fastest route to a clear answer on interactions.

Who Should Avoid Yellow Adonis Completely

• Anyone taking digoxin or another cardiac glycoside.
• Anyone with diagnosed heart disease or an arrhythmia. Self-medicating an unstable heart with an unmeasured glycoside is the highest-risk scenario there is.
• People who are pregnant or breastfeeding. The plant is considered poisonous and likely unsafe in pregnancy and lactation, and should be avoided [Therapeutic Research Center via WebMD, 2026]. Reproductive and teratogenicity studies have never been performed on this species [EMEA, 1998] — the absence of a documented harm signal here reflects the absence of research, not a clean safety record.
• Children and adolescents under 18.
• Anyone with low blood potassium, or on medication that lowers it.
• Anyone with kidney impairment or who becomes dehydrated easily, since clearance of cardiac glycosides depends on kidney function.
• Anyone who cannot verify exactly what species and preparation they have.

Homeopathic Preparations Are a Separate Question

Adonis vernalis appears in homeopathic pharmacopeias, including in the United States, typically as a mother tincture and as 1:100 or greater dilutions [EMEA, 1998]. The toxicity described on this page applies to herbal-strength material — dried herb, teas, and concentrated extracts — not to high homeopathic dilutions, which contain little or no plant material. Whether homeopathic dilutions do anything therapeutically is a separate scientific debate and outside the scope of this article. What matters here is not confusing the two categories: a mother tincture is not a high dilution.

A Protected Species

There is a conservation dimension worth knowing. Yellow adonis was added to Appendix II of the Convention on International Trade in Endangered Species (CITES) at the eleventh Conference of the Parties, with the listing taking effect on July 19, 2000; the annotation covers dried specimens, whole or in part. The United States supported the listing and entered no reservation [US Fish and Wildlife Service, Federal Register 66 FR 27601, 2001]. Appendix II covers species that are not necessarily threatened with extinction now but may become so unless trade is closely controlled [CITES]. Wild populations have declined across Central Europe, and commercially traded dried adonis herb requires CITES export documentation. Wild-harvesting this plant is not a casual act.

When to Talk to a Doctor

If you came to this page because of a heart symptom, that symptom deserves a diagnosis rather than an herb. Palpitations, breathlessness on mild exertion, ankle swelling, unusual fatigue, or a pulse that feels irregular can all point to conditions that are very treatable when identified — and that get worse when self-managed.

• Book with your primary care doctor for new or worsening palpitations, shortness of breath, swelling in the legs or ankles, or unexplained fatigue.
• Go to urgent care or the ER for fainting, a persistently slow or racing pulse, or new chest discomfort that resolves with rest.
• Call 911 for chest pain lasting more than a few minutes, chest pain with sweating or nausea, severe breathlessness, or collapse.

If your interest is in herbs with a cardiac reputation more generally, the evidence picture differs a great deal from plant to plant — our overview of herbs for the heart and the wider cardiovascular health section cover that ground. Bring any herbal product you are considering to your doctor or pharmacist before starting it, especially if you take prescription medication.

Health Disclaimer: This article is for general education only and is not medical advice. Yellow adonis (Adonis vernalis) is a poisonous plant containing cardiac glycosides with a narrow margin between an active and a toxic dose. Nothing here should be read as a recommendation to gather, prepare, take, or give this plant in any form. No home-preparation or dosing instructions are provided, and none should be inferred. Do not use yellow adonis if you are pregnant or breastfeeding, if you take digoxin or any heart medication, or if you have heart disease, kidney disease, or low potassium. Do not give it to children. Talk to your doctor or pharmacist before using any herbal product, particularly alongside prescription medication. If someone has swallowed this plant or a preparation of it, contact Poison Control at 1-800-222-1222 or call 911 immediately — do not wait for symptoms to appear.

Frequently Asked Questions

References

1. Shang X, Miao X, Yang F, Wang C, Li B, Wang W, Pan H, Guo X, Zhang Y, Zhang J. “The Genus Adonis as an Important Cardiac Folk Medicine: A Review of the Ethnobotany, Phytochemistry and Pharmacology.” Frontiers in Pharmacology, 2019;10:25. DOI 10.3389/fphar.2019.00025. PMID 30778296. → View source
2. European Agency for the Evaluation of Medicinal Products, Committee for Veterinary Medicinal Products. “Adonis vernalis: Summary Report.” EMEA/MRL/543/98-FINAL, December 1998. → View source
3. MedlinePlus Medical Encyclopedia. “Cardiac glycoside overdose.” US National Library of Medicine, National Institutes of Health. Review date July 1, 2025. → View source
4. Therapeutic Research Center. “Pheasant’s Eye (Adonis vernalis).” Natural Medicines monograph, published via WebMD, 2026. → View source
5. US Fish and Wildlife Service, Department of the Interior. “Changes in List of Species in Appendices to the Convention on International Trade in Endangered Species of Wild Fauna and Flora.” Federal Register, 66 FR 27601, May 18, 2001. → View source
6. Convention on International Trade in Endangered Species of Wild Fauna and Flora. “The CITES Appendices.” CITES Secretariat. → View source