A reference sheet for journalists, editors and fact-checkers covering mad honey. Every figure is attributed to a named source and links to the page carrying the underlying study. Material on this page may be quoted with attribution to the Cliff Mad Honey Index.
The 60-second version
Mad honey is honey containing grayanotoxins, a class of diterpenoid polyol compounds produced by plants in the family Ericaceae, chiefly rhododendrons. Bees foraging predominantly on grayanotoxin-bearing nectar carry the compounds through to the jar. Grayanotoxins act on voltage-gated sodium channels in nerve and cardiac tissue, so the effects are cardiovascular and neurological: slowed heart rate, low blood pressure, nausea, dizziness. Concentration varies enormously between batches, which is the single most important fact for anyone writing about it.
The error that appears most often in coverage
Commonly written: that mad honey is psychedelic, hallucinogenic, or psychoactive in the recreational sense.
What the pharmacology supports: grayanotoxins bind receptor site 2 on voltage-gated sodium channels and interfere with channel inactivation. They do not act on serotonergic receptors, which is the mechanism behind classical psychedelics. The reported human experience is dominated by bradycardia, hypotension, nausea and dizziness rather than by perceptual change.
The accurate framing is that mad honey is a cardiotoxic and neurotoxic food, historically used as a folk medicine and as a weapon, not a plant psychedelic. Sources: Jansen et al. 2012; What Are Grayanotoxins; Mechanism and Clinical Presentation of Mad Honey Poisoning: What Jansen et al. (2012) Established.
Figures that can be cited
Each figure below is reproduced from the named study or assessment. Cite the primary paper; this site is the secondary reference.
Range in grayanotoxin I concentration across 60 Nepalese mad honey samples analysed by LC-MS/MS, from 0.75 to 64.86 micrograms per gram. A claim about the strength of mad honey in general is not supportable.
Share of 1,199 published cases showing sinus bradycardia on the ECG, in the largest systematic review of mad honey intoxication. Hypotension, nausea and vomiting, and dizziness are the other common presenting signs.
Deaths reported across the 1,199 cases in the largest systematic review of mad honey intoxication. Most patients were treated with atropine and intravenous fluids and discharged within 24 hours of recovery.
Structurally distinct grayanotoxins characterised to date. GTX I and GTX III dominate Rhododendron nectar and are the most biologically active; GTX I is the 14-O-acetyl derivative of GTX III.
Species in the Rhododendron genus. Grayanotoxin production is not universal across the genus, and among producing species the concentration differs.
The European Food Safety Authority found that every concentration it assessed, from 0.1 mg/kg up to the 1 and 10 mg/kg measured in mad honeys, raised health concerns for acute toxicity, and based its protective concentration on toddlers.
Two further points that change a story
Most documented poisonings follow deliberate use, not accidental contamination. The typical patient in the Turkish case series is a middle-aged man who ate deli bal on purpose, often as a folk remedy (Silici and Atayoglu 2015; EFSA 2023); the poisoning itself is unintended. Coverage framing poisoning as accidental contamination misdescribes the literature.
Grayanotoxins are stable in stored honey. Concentration does not decrease meaningfully over normal storage. Age is not a mitigating factor, and a claim that older honey is weaker is not supported.
How concentration is reported
Laboratory results are reported in milligrams per kilogram of honey, or equivalently in micrograms per gram; the two units are numerically identical. Concentration describes the honey. Dose describes the exposure.
The only formula that matters
delivered dose (mg) = concentration (mg/kg) x serving (kg)
Honey at 20 mg/kg in a 20 g serving delivers 0.4 mg of grayanotoxin. Honey at 50 mg/kg in the same serving delivers 1.0 mg. The concentration on a certificate describes the honey; only the serving decides the exposure. Use the dose calculator.
| Band | Total GTX I + III (mg/kg) | Grayanotoxin in a 20 g serving |
|---|---|---|
| Trace | under 1 | under 0.02 mg |
| Low | 1 to 10 | 0.02 to 0.2 mg |
| Moderate | 10 to 30 | 0.2 to 0.6 mg |
| High | over 30 | over 0.6 mg |
Serving column is concentration multiplied by a 20 g serving, shown to make the difference between concentration and delivered dose concrete. Bands are documented ranges drawn from the clinical and laboratory literature. They are not safe-versus-unsafe categories, and no concentration has been shown safe for everyone: the level EFSA judged protective for all age groups, 0.05 mg/kg (GTX I and III combined), covers acute poisoning only, not genotoxicity or other grayananes.
What is not established
Reporters are frequently offered claims in this category. None is currently supported by evidence that would meet a clinical standard.
Medicinal benefit in humans
Grayanotoxins have a documented mechanism, and mad honey has a long ethnographic record of traditional use. Neither establishes clinical benefit. The therapeutic-potential literature is preclinical and exploratory, and there are no controlled human trials showing benefit at a defined dose with an acceptable safety margin. See the review.
A safe serving size
Because concentration varies by batch to the degree documented above, a serving described in spoons carries no fixed grayanotoxin content.
Aphrodisiac effect
Frequently claimed in marketing and in coverage. Not established in the literature.
A reliable sensory test
There is no colour, taste or texture cue that indicates concentration. Only laboratory analysis of the specific batch does.
Consistency within a producer or region
A tested batch says nothing about the next batch from the same source.
Questions worth asking about any specific claim
- Which batch does this laboratory result refer to, and is the batch identifier on both the certificate and the jar?
- Which grayanotoxin isoforms were measured, and was a total reported?
- Which analytical method was used, and what were its limits of detection and quantification?
- Is a health claim supported by a mechanism, by traditional use, or by a controlled trial in humans? Only the third supports the claim.
- Is a quoted toxicity figure an animal LD50? If so, which isoform, which species, which route of administration, and has the extrapolation caveat been stated?
Terminology and geography
Deli bal
The Turkish name, associated principally with the Black Sea provinces of Rize and Trabzon, the source of most published clinical case series.
Himalayan mad honey
Produced in Nepal, and the subject of most published quantitative concentration work, including the 60-sample LC-MS/MS study above.
GTX honey
An informal trade and laboratory shorthand for the same material. It carries no separate technical meaning and is not a grade.
Full definitions for every term used here are in the grayanotoxin glossary.
Primary sources referenced on this page
| Authors | Title | Publication | DOI |
|---|---|---|---|
| Ahn SY, Kim S, Cho H | Determination of Grayanotoxin I and Grayanotoxin III in mad honey from Nepal using liquid chromatography-tandem mass spectrometry | Analytical Science and Technology 2022;35(2):82-91 | 10.5806/ast.2022.35.2.82 |
| Jansen SA, Kleerekooper I, Hofman ZLM, Kappen IFPM, Stary-Weinzinger A, van der Heyden MAG | Grayanotoxin Poisoning: ‘Mad Honey Disease’ and Beyond | Cardiovascular Toxicology 2012;12(3):208-215 | 10.1007/s12012-012-9162-2 |
| Ullah S, Khan SU, Saleh TA, Fahad S | Mad honey: uses, intoxicating/poisoning effects, diagnosis, and treatment | RSC Advances 2018;8:18635 to 18646 | 10.1039/c8ra01924j |
| Aryal M | Grayanotoxins in Mad Honey: Mechanisms of Toxicity, Clinical Management, and Therapeutic Implications | Journal of Applied Toxicology 2025;45(11):2240–2256 | 10.1002/jat.4855 |
| Aygun A, Sahin A, Karaca Y, et al. | Grayanotoxin levels in blood, urine and honey and their association with clinical status in patients with mad honey intoxication | Turkish Journal of Emergency Medicine 2018;18(1):29-33 | 10.1016/j.tjem.2017.05.001 |
| Demir H, Denizbasi A, Onur O | Mad honey intoxication: a case series of 21 patients | ISRN Toxicology 2011;2011:526426 | 10.5402/2011/526426 |
| EFSA CONTAM Panel | Risks for human health related to the presence of grayanotoxins in certain honey | EFSA Journal 2023;21(3):7866 | 10.2903/j.efsa.2023.7866 |
| Silici S, Atayoglu AT | Mad honey intoxication: a systematic review on the 1199 cases | Food and Chemical Toxicology 2015;86:282-290 | 10.1016/j.fct.2015.10.018 |
The full annotated set, including the studies not cited directly above, is in the research references index.
Using this material
Figures and definitions on this page may be quoted with attribution to the Cliff Mad Honey Index, with a link to the page carrying the underlying source. Where a figure originates in a peer-reviewed paper, cite the paper as the primary source; this site is the secondary reference.
The Cliff Mad Honey Index is an independent, non-commercial reference on mad honey and grayanotoxin. It does not sell mad honey, certify products, or designate any concentration as safe.
Scope note. This page is a reference for reporting. It is not medical advice and not a dosing guide. Anyone who suspects mad honey poisoning should seek emergency medical care.
