The Artemisia genus contains more than 500 species, and three of them keep getting tangled together in supplement listings: wormwood, sweet wormwood, and mugwort. We have covered wormwood against sweet wormwood separately, because that pair is separated by artemisinin.
This article covers the harder pair. Wormwood and mugwort are closer to each other in chemistry, in appearance, and in how they are traded, which is precisely why they are easier to mix up. Nothing here is medical advice, and neither plant has been approved by the FDA to diagnose, treat, cure, or prevent any disease.
Key Takeaways
- Wormwood is Artemisia absinthium; mugwort is Artemisia vulgaris. Same genus, different species.
- Both contain thujone. A 49-year-old man was hospitalised in a manic state after drinking a litre of mugwort infusion, with serum thujone measured at 27.7 micrograms per millilitre [1].
- Before that case, adverse effects had been associated only with essential oil from wormwood [1]. The mugwort case widened the concern.
- Species substitution is a documented hypothesis, not a theoretical one: the investigators listed adulteration with another Artemisia species among four possible explanations for that case [1].
- Mugwort is a leading cause of late summer pollinosis in Europe, with more than 95 percent of affected patients sensitized to Art v 1, and cross-reactive structures were found in A. absinthium pollen [2].
- Their polyphenol profiles differ: chlorogenic acid, rosmarinic acid, and rutin in wormwood; chlorogenic acid, luteolin, and rutin in mugwort [3].
- In head-to-head enzyme testing, mugwort inhibited alpha-amylase more strongly than wormwood [3].
Two Species, Two Reputations
The names carry most of the confusion. Both plants are grey-green, aromatic, bitter members of the daisy family, and both have been used for centuries in European folk medicine for digestive complaints and for expelling worms. The English name mugwort and the older English name for wormwood overlap in the popular imagination in a way the botany does not support.
Wormwood, Artemisia absinthium, is the more chemically extreme of the two and the one with a cultural reputation attached. It is the defining botanical of absinthe, which is where the species epithet comes from, and its bitterness is driven by sesquiterpene lactones including absinthin. Its literature is dominated by thujone and by whether traditional digestive and antiparasitic uses hold up.
Mugwort, Artemisia vulgaris, is used more as a culinary and ritual herb across Europe and East Asia, and it is the plant burned in moxibustion. In the medical literature its largest presence by far is as an aeroallergen rather than as a remedy.
Those different centres of gravity mean that reading across from one species to the other, in either direction, produces a wrong answer.
The Thujone Point That Changes the Safety Framing
Anyone who has read about wormwood knows the thujone story. What is less widely known is that thujone is a genus-level issue rather than a wormwood-only one, and one case report makes that unusually concrete.
A 49-year-old man was admitted to a Zurich emergency department in a manic state after ingesting one litre of an infusion of Artemisia vulgaris. Investigators validated an HPLC method with fluorescence detection and confirmed by gas chromatography, measuring serum thujone at 27.7 micrograms per millilitre on admission and 24.1 the next day. Thujone poisoning was confirmed [1].
The paper is explicit that this widened the picture. It notes that both alpha- and beta-thujone are present in various concentrations across Artemisia species, but that adverse effects had previously been associated only with essential oil from Artemisia absinthium, attributed to inhibition of GABA receptors with consequent excitation and convulsions [1].
The four explanations the authors offered are each worth holding onto: an unusually high thujone concentration in the mugwort ingested, chronic exposure, low metabolic efficiency in that particular patient, or contamination or adulteration of the plant material with another Artemisia species, for example A. absinthium [1].
Every one of those is a supply-chain or individual-variation problem rather than a dose problem, and none of them is visible to the person drinking the tea.
Why Substitution Is Plausible and Hard to Catch
Species mix-ups in the herb trade are not exotic. They happen where three conditions hold at once, and they hold here.
The plants resemble each other. Both are aromatic Artemisia species with divided grey-green foliage. Dried and cut for tea, the distinguishing features are largely gone. Our identification guide covers what actually separates them on a living plant.
Both are sold loose and unstandardized. A bag of cut herb carries a name on a label and nothing verifiable behind it.
Thujone content varies within each species anyway. Chemotype, growing conditions, and processing all shift it [4]. Because the natural range is wide, a substituted or contaminated batch does not necessarily look anomalous.
The practical consequence is that a species claim on loose herb is only as good as the supplier’s testing. This is one of the clearer arguments for buying products with third-party verification rather than loose plant material of unverified origin, and it is the same class of problem covered in our comparison of wormwood and wormseed.
The Allergy Connection Runs Both Ways
Mugwort’s main presence in the medical literature is as an allergen, and that turns out to be directly relevant to wormwood.
Artemisia vulgaris is one of the main causes of late summer pollinosis in Europe, and more than 95 percent of sensitized patients react to the glycoallergen Art v 1 [2].
A 2009 study set out to map how far that reactivity extends. Using monoclonal antibodies against a cysteine-stabilized epitope of the Art v 1 defensin domain and against carbohydrates attached to its proline domain, alongside polyclonal Art v 1-specific rabbit sera, the investigators identified cross-reactive structures in pollen from botanically related Asteraceae weeds, naming Artemisia absinthium, sunflower, and ragweed. Homologous allergens were recognised by IgE from mugwort-sensitized patients, and that reactivity could be reduced by pre-incubating the serum with Art v 1 [2].
Two qualifications keep this accurate. The study examined pollen, not leaf extracts or supplements, and the exposure route for hay fever is inhalation rather than ingestion. And the authors concluded that Art v 1 is poorly involved in cross-reactivity between mugwort pollen and the foods associated with mugwort pollinosis, because no cross-reactive structures were found in those foods [2].
What it does establish is that these two species share antigenic structures at the molecular level. Anyone with known Asteraceae or mugwort sensitivity has a concrete reason to raise wormwood with a clinician before using it, which is covered further in who should avoid wormwood.
Where the Chemistry Actually Diverges
One study put the two species through identical processing and identical assays, which makes it the cleanest available comparison.
Extracts of A. absinthium, A. vulgaris, and fenugreek were concentrated by micro- and ultrafiltration and profiled by HPLC. Wormwood yielded chlorogenic acid, rosmarinic acid, and rutin. Mugwort yielded chlorogenic acid, luteolin, and rutin. Two shared markers, one distinct compound each [3].
On function, the concentrated mugwort extract inhibited alpha-amylase with an IC50 of 8.57 micrograms per millilitre against acarbose at 3.5, while fenugreek matched acarbose closely at 3.22. Fenugreek also led on lipoxygenase inhibition at 19.69 micrograms per millilitre [3]. Wormwood did not top either measure.
Read carefully, that is a useful corrective in both directions. Mugwort is not a weaker cousin of wormwood; on this particular measure it performed better. And neither Artemisia was the strongest herb in its own study. Our article on wormwood and blood sugar covers what that means for metabolic claims, which is less than the marketing suggests.
What to Do With This
Three practical takeaways.
Confirm the binomial, not the common name. Wormwood, absinthe wormwood, green ginger, and mugwort circulate loosely as labels. Artemisia absinthium and Artemisia vulgaris are unambiguous, and a supplier who will not print the binomial is telling you something.
Do not treat thujone as a wormwood-only issue. The measured poisoning case involved mugwort [1]. Volume and duration matter for both.
Take Asteraceae sensitivity seriously across the genus. Shared antigenic structures between the two species are documented [2], so a known mugwort allergy is a reason to ask a clinician before trying wormwood rather than to assume they are unrelated.
A Note on the Evidence
Both species contain thujone and both are sold as loose herb, which makes substitution plausible and hard to detect. Species-level identity claims should be verified rather than assumed.
Frequently Asked Questions
Are wormwood and mugwort the same plant?
No. Wormwood is Artemisia absinthium and mugwort is Artemisia vulgaris. They are separate species in the same genus, with different chemistry and different traditional uses.
Which one is in absinthe?
Wormwood, Artemisia absinthium. The species name is the origin of the drink’s name. Mugwort has its own culinary and ritual uses and is not the defining absinthe botanical.
Do both contain thujone?
Yes, and that is the important safety point. A documented poisoning case involved mugwort infusion with serum thujone measured at 27.7 micrograms per millilitre [1]. Thujone is not a wormwood-only concern.
Can one be sold as the other?
It is a documented possibility. In that same case the investigators listed contamination or adulteration of the plant material with another Artemisia species, giving A. absinthium as the example, among four candidate explanations [1].
Is mugwort allergy relevant to wormwood?
Yes. Mugwort pollen is a major cause of late summer hay fever in Europe, with over 95 percent of affected patients sensitized to the allergen Art v 1, and cross-reactive structures have been identified in wormwood pollen [2].
Which is stronger for blood sugar in lab testing?
Mugwort, in the one direct comparison. Its extract inhibited alpha-amylase with an IC50 of 8.57 micrograms per millilitre; wormwood did not lead on that measure [3]. Both were beaten by fenugreek.
References
- Di Lorenzo C et al. Identification and Quantification of Thujone in a Case of Poisoning Due to Repeated Ingestion of an Infusion of Artemisia vulgaris L. Journal of Food Science (2018). PMID 30044501
- Gruber P et al. Role of the polypeptide backbone and post-translational modifications in cross-reactivity of Art v 1, the major mugwort pollen allergen. Biological Chemistry (2009). PMID 19361284
- Neagu E et al. In Vitro Assessment of the Antidiabetic and Anti-Inflammatory Potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum Extracts Processed Using Membrane Technologies. Molecules (2023). PMID 37894635
- Lachenmeier DW. Wormwood (Artemisia absinthium L.), a curious plant with both neurotoxic and neuroprotective properties? Journal of Ethnopharmacology (2010). PMID 20542104
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.