Shallot (Allium ascalonicum)

The shallot is the small, clustered, purple-skinned allium that sits at the base of almost every Southeast Asian curry paste and sambal, and that becomes the crisp fried shallots scattered over noodles, rice porridge and salads from Hanoi to Jakarta. In the West it is better known as the refined onion of French sauce-making. It is milder and sweeter than a common onion raw, and more complex when cooked.

Two honest caveats lead this page. First, the taxonomy: modern botanical treatments regard the shallot as a variety of the common onion — Allium cepa Aggregatum Group — rather than a separate species, though the old name Allium ascalonicum persists in older literature, in seed catalogues and on supplement labels. Second, the evidence: the health literature on alliums is overwhelmingly about garlic and common onion. Shallot-specific human data is thin. This page will not borrow garlic's clinical trials and pin them on the shallot.

Table of Contents

  1. Overview: The Plant and the Bulb
  2. The Taxonomy Problem
  3. Names and Identification
  4. Traditional Use
  5. Active Compounds
  6. Polyphenols: Where Shallots Genuinely Differ From Onions
  7. Antimicrobial Activity
  8. Cardiovascular and Metabolic Evidence — and Its Limits
  9. Antioxidant and Anti-Inflammatory Effects
  10. Culinary Use
  11. Forms and Preparations
  12. Dosage
  13. Cautions and Contraindications
  14. Key Research Papers
  15. Connections

Overview: The Plant and the Bulb

The shallot is a bulbous perennial in the family Amaryllidaceae, subfamily Allioideae — the same family as onion, garlic, leek and chive. Its defining habit is that it is a multiplier onion: plant one bulb and instead of swelling into a single large onion, it divides underground into a cluster of several small bulbs, each sharing a papery outer skin. That is why shallots come in lobed clusters and why a single "shallot" often separates into two or three cloves the way garlic does.

Because they multiply vegetatively, shallots have traditionally been propagated by replanting bulbs rather than by seed. In practice this means many local shallot populations are clonal landraces — regional strains maintained by generations of farmers — which explains a great deal of the variation between "shallots" from different countries.

Two rather different products travel under the name. The Southeast Asian shallot is small, often no bigger than a large marble, with a deep red-purple skin, dense flesh and a sharp, concentrated flavour. It is grown at enormous scale in Indonesia, Vietnam, Thailand and the Philippines and is a daily staple — a genuine dietary foundation rather than a garnish. The European shallot is larger, more elongated, with a coppery-brown or greyish skin and a milder, sweeter character; the French grey shallot (échalote grise) is a separate, more strongly flavoured type prized in French kitchens.

The whole plant is edible. The green tops are used like scallion greens. The bulbs are used fresh, dried, fried, pickled and ground into pastes. In Southeast Asia the crop is harvested, cured in the sun until the skins rustle, and then plaited or bagged for storage; well-cured shallots keep for months, which is one reason they became a year-round backbone of the regional kitchen.

The Taxonomy Problem

Shallot nomenclature is genuinely unsettled, and it is worth stating plainly rather than pretending there is a single right answer.

The old name: Allium ascalonicum Strand. It refers to Ascalon (modern Ashkelon, on the coast of the Levant), which classical and medieval writers believed was the plant's origin. The English word "shallot" descends from the same root — Latin ascalonia caepa, "onion of Ascalon," through Old French eschalotte. The etymology is charming and the geography is almost certainly wrong; the shallot's actual origins are in Central and Southwest Asia along with the rest of the cultivated onions.

The modern treatment: most contemporary botanical and horticultural sources treat the shallot as Allium cepa L., Aggregatum Group — a cultivar group of the ordinary onion, sometimes written Allium cepa var. aggregatum. On that view the shallot is not a separate species at all; it is an onion that multiplies instead of bulking up. The potato onion and the multiplier onion belong to the same group. Genetic and morphological work generally supports this, and the name A. ascalonicum is widely regarded as illegitimate or, at best, a synonym.

Why the old name survives. Seed catalogues, agricultural extension documents, supplement labels and a large slice of the published research still say Allium ascalonicum. If you search the literature you must search both names or you will miss half of it. This page uses the traditional binomial in its title for exactly that reason, while stating the modern position.

Complications you should know about:

Names and Identification

Accepted name: Allium cepa L. Aggregatum Group. Traditional binomial: Allium ascalonicum Strand. Family: Amaryllidaceae.

A translation trap

Indonesian and Malay bawang merah translates literally as "red onion," and English recipe translations routinely render it that way. In an Indonesian, Malaysian or Singaporean recipe, bawang merah means shallot, not the large red salad onion. Substituting red onion in a rempah or sambal gives a wetter, sweeter, less concentrated paste. The parallel terms are worth memorising: bawang putih ("white onion") is garlic, and bawang bombay is the large common onion.

Telling shallots apart in the shop

A shallot has a papery skin like an onion but the bulb is elongated or teardrop-shaped rather than round, usually lobed, and cutting it lengthwise reveals two or three distinct bulbs sharing one skin. The flesh is denser and tighter-ringed than an onion's, often with a violet flush. Southeast Asian shallots are small and deep red-purple; European ones are bigger and browner. Pearl onions and small red onions are the usual imposters — both are single-bulbed with concentric rings all the way through.

Traditional Use

The shallot's traditional identity is overwhelmingly culinary. Its medicinal reputation is mostly inherited from the alliums as a class rather than earned separately, and it is usually described in the same breath as onion and garlic.

Southeast Asia. In Indonesian jamu and Malay traditional practice, shallot is a warming, digestive ingredient and appears in preparations for colds and fevers. A widespread and still-common Indonesian home practice is to rub a mixture of grated shallot and coconut oil onto a feverish child's body — a comforting ritual with no evidence of any antipyretic effect. In Vietnamese folk practice, shallot appears in preparations for colds, coughs and digestive complaints, and in the New Year tradition of pickled shallots (dưa hành) eaten with rich Tết food, a use that is at least partly digestive in intent.

Thailand. Shallot is one of the standard components of Thai traditional medicine formulas for cold and respiratory symptoms, generally in combination rather than alone.

South Asia and the Middle East. Small onions and shallots are used in Ayurvedic and Unani preparations, again largely interchangeably with onion, for digestion, cough and topical application to boils and stings.

Europe. Shallots were grown in medieval European gardens and appear in herbals as a milder alternative to onion, with the same general reputation: digestive, warming, applied to bites and swellings.

All of this is history. None of it is evidence that the shallot treats anything.

Active Compounds

Organosulfur compounds

Like all alliums, shallots store their sulfur chemistry in an inactive form and detonate it on damage. Intact cells hold non-volatile cysteine sulfoxides in the cytoplasm and the enzyme alliinase in the vacuole, kept apart. Cutting, crushing or chewing breaks the compartments, alliinase meets its substrates, and within seconds you get reactive thiosulfinates plus the smell.

An accuracy point that matters. Garlic's dominant cysteine sulfoxide is alliin, which converts to allicin. Onion-type alliums — including shallots — are dominated instead by isoalliin (trans-S-1-propenyl-L-cysteine sulfoxide), along with methiin and propiin. These yield a different family of propenyl- and propyl-derived thiosulfinates, and they also feed a second enzyme, lachrymatory factor synthase, which produces the volatile compound that makes you cry. Shallots therefore produce allicin-family thiosulfinates but very little allicin proper. Any label claiming a shallot product is standardised for allicin content should be read sceptically.

Downstream of the thiosulfinates come the compounds usually credited with allium bioactivity: diallyl and dipropyl sulfides, ajoene-type compounds, vinyldithiins and various polysulfides. They are unstable, and how you treat a shallot changes what you get. Chopping and waiting a few minutes before heating allows the enzymatic step to run to completion; dropping whole shallots straight into hot oil denatures alliinase before much happens.

Flavonoids

Nutrients and fibre

Shallots supply modest amounts of vitamin C, vitamin B6, folate, potassium and manganese, and a meaningful quantity of fructans — inulin-type prebiotic fibres that feed colonic bacteria. Those fructans are also, as the Cautions section explains, why shallots are a high-FODMAP food.

Polyphenols: Where Shallots Genuinely Differ From Onions

Most claims that food A is "healthier" than food B do not survive checking. This one largely does.

The finding. Yang, Meyers, van der Heide and Liu, publishing in the Journal of Agricultural and Food Chemistry in 2004, compared phenolic content, antioxidant activity and antiproliferative activity across a range of onion varieties and shallots. Shallots ranked at or near the top for total phenolic content and antioxidant capacity, well above the mild, sweet onion types. Later work has generally been consistent with the pattern: the pungent, deeply pigmented alliums carry the most polyphenol, and shallots are pungent and deeply pigmented.

Why it is true. Flavonols concentrate in the outer layers of an allium bulb, and a shallot is essentially all outer layer — small bulbs have a much higher surface-to-volume ratio than a big onion. Add the anthocyanins of the purple skin and flesh, which sweet yellow onions simply do not have, and the difference is structural rather than accidental.

Bioavailability. Onion-family quercetin is unusually well absorbed for a flavonoid, because the glucoside forms are efficiently taken up in the small intestine — better than the rutinoside form found in tea and buckwheat. Nemeth and Piskula reviewed onion flavonoid content, processing and metabolism in 2007. Mullen and colleagues traced quercetin metabolites in human plasma and urine after onion ingestion. Lee and Mitchell compared quercetin pharmacokinetics from apples and onions in healthy people. And Wiczkowski and colleagues, publishing in the Journal of Nutrition in 2008, worked specifically with shallots (which they identified as Allium cepa L. var. aggregatum) to compare the bioavailability of quercetin aglycone against its glucosides in humans.

What this does and does not mean. It means that if you are eating alliums partly for polyphenols, shallots are a better vehicle than a sweet white onion, and that the quercetin in them actually reaches your bloodstream. It does not mean shallots have been shown to prevent any disease. Higher polyphenol intake is associated with better cardiovascular outcomes in observational nutrition research, but that is a population-level association across whole dietary patterns, not a demonstrated effect of shallots.

Antimicrobial Activity

Mechanism. Thiosulfinates are electrophilic and react with thiol groups on microbial enzymes, disabling them. This is old and well-characterised chemistry, and it is why crushed alliums inhibit a wide range of bacteria and fungi in the laboratory.

Evidence: cell culture and in vitro, with a long history. Dankert and colleagues compared the antimicrobial activity of crude juices of Allium ascalonicum, Allium cepa and Allium sativum as far back as 1979. Amin and Kapadnis reported heat-stable antimicrobial activity of A. ascalonicum against bacteria and fungi in 2005. Saenthaweesuk and colleagues investigated antimicrobial and wound-healing potential in 2015. Mobin and colleagues characterised the antibacterial and antioxidant activity of phenolic extracts from shallot peel in 2022 — a reminder that a good deal of allium research is done on the part you throw away. There is also applied animal work: Surasorn and colleagues fed shallot powder to broiler chickens and reported effects on gut morphology, immune measures and intestinal bacteria.

What is missing. Human trials. There is no evidence that eating shallots treats a bacterial infection, and no evidence that shallot preparations applied to human wounds outperform standard care. Allium antimicrobial chemistry is real; allium antibiotics are not a thing. Never delay antibiotics for a genuine infection in favour of food.

Cardiovascular and Metabolic Evidence — and Its Limits

This is where the temptation to borrow is strongest, so this section says clearly what belongs to which plant.

What the allium literature actually contains. There is a large body of human research — including randomised trials and meta-analyses — on garlic and blood pressure, lipids and platelet function, with generally modest effects. There is a smaller but real human literature on common onion and on isolated quercetin supplementation, again with modest and inconsistent effects on blood pressure and lipid markers. Observational studies of overall allium consumption and cardiovascular or cancer risk exist and mostly point in a favourable direction, with all the usual confounding that dietary epidemiology carries.

What exists specifically for shallots. Very little in humans. Most shallot-specific work is animal or cell-based. Wongmekiat and colleagues reported that shallot extract reduced cyclosporine-induced kidney injury in rats — interesting, but rats. Chuljerm and colleagues reported that shallot extracts protected human nasal epithelial cells against oxidative stress from polycyclic aromatic hydrocarbons — cell culture. Arpornchayanon and colleagues investigated antiallergic activity of shallot and its effects in allergic rhinitis, which is one of the few shallot studies to reach into the clinical space at all.

A trap to avoid. A double-blind randomised trial published in 2025 reported effects of "Persian shallot" extract on serum markers and blood pressure in metabolic syndrome. That is a genuine trial, but Persian shallot (moosir) is Allium hirtifolium / A. stipitatum, not the shallot in your kitchen. Marketers cite it anyway. This is exactly the kind of species substitution that makes allium claims unreliable.

The honest position. Shallots are a nutritious, polyphenol-rich vegetable and a sensible part of a diet associated with good cardiovascular health. There is no trial showing that eating shallots lowers your blood pressure, your cholesterol or your blood sugar. Anyone selling shallot capsules on the strength of the garlic literature is selling you someone else's evidence.

Antioxidant and Anti-Inflammatory Effects

Mechanism. Two separate systems. Quercetin and the anthocyanins are direct radical scavengers in chemical assays, and quercetin also modulates inflammatory signalling — inhibiting NF-κB activation and reducing cytokine output in cell models. The organosulfur compounds work differently and, arguably, more interestingly: rather than mopping up radicals directly, they activate the Nrf2 pathway, which switches on the cell's own antioxidant enzymes such as glutathione S-transferase and NAD(P)H quinone dehydrogenase. That indirect mechanism is a better explanation for allium effects than the simple "antioxidant" framing.

Evidence level: cell culture and animal. The nasal epithelial cell work by Chuljerm and colleagues is a good example of the genre — a plausible protective effect against a real environmental toxin, demonstrated in cultured human cells. Rodent studies of shallot extract on oxidative-stress markers exist in reasonable number. Human outcome data does not.

Processing changes the chemistry. Ratseewo and colleagues, in Food Chemistry: X in 2025, measured how different drying methods change the chemical composition, volatiles and retention of bioactive compounds in shallots. This is directly relevant to how most people actually eat them: deep-frying shallots into crisp bawang goreng destroys alliinase, drives off volatiles and browns the sugars. Fried shallots are delicious. They are not the same food, chemically, as a raw one.

Culinary Use

The shallot's real claim on your attention is culinary, and it is a strong one.

Southeast Asia: the base of everything

Shallot is the first ingredient in the mortar across the region. Thai curry pastes (krueang gaeng) begin with shallot, garlic, galangal, lemongrass and chilli. Malay and Indonesian rempah — the pounded spice paste underlying rendang, gulai, laksa and countless sambals — is built on shallot. Indonesian sambal, in its hundreds of regional forms, is usually shallot, chilli and salt at minimum. Vietnamese cooking uses hành tím in marinades, braises, dipping sauces and pickles. Nyonya, Burmese, Cambodian and Filipino cooking all lean on it the same way.

The technique matters: the paste is fried slowly in oil until the raw sharpness cooks off and the mixture darkens and separates — tumis in Indonesian. This is where the flavour actually gets built, and it takes longer than most Western recipes suggest.

Fried shallots

Crisp fried shallots — hành phi, bawang goreng, hom jiao — are one of the great garnishes of world cooking, scattered over pho, congee, nasi goreng, laksa, salads and steamed vegetables. Slice thinly and evenly, start in cool oil, fry slowly over moderate heat, and pull them out while still golden rather than brown, because they keep cooking after they leave the pan. Save the shallot-infused oil — it is as valuable as the crisps. Store the crisps airtight; they go soft fast in humidity.

Elsewhere

French cooking uses shallot where onion would be too coarse: minced raw in vinaigrette, in mignonette for oysters, reduced in wine for beurre blanc and sauce bordelaise, and in butter compounds. Shallots are also excellent roasted whole until sweet and collapsing, pickled in vinegar, or confited slowly in oil or duck fat.

Practical notes

Forms and Preparations

Dosage

There is no established medicinal dose of shallot, because there is no condition for which shallot has been shown to work in humans. No dose-ranging study exists, and no standardised shallot extract has an accepted potency measure.

What can be said sensibly:

Cautions and Contraindications

1. FODMAPs and IBS. Shallots are high in fructans and are classified as a high-FODMAP food. For people with irritable bowel syndrome they are one of the more reliable triggers of bloating, wind and pain, and they are excluded during the elimination phase of a low-FODMAP diet. Because fructans are water-soluble but not oil-soluble, shallot-infused oil with the solids strained out is generally tolerated — a genuinely useful trick that lets people with IBS keep the flavour. Fried shallot crisps, being the solids themselves, are not a workaround.

2. Reflux and gastritis. Alliums, particularly raw, are a common trigger for gastro-oesophageal reflux. If onions bother you, shallots will too.

3. Allergy and contact dermatitis. Allium allergy is uncommon but real, and can cause oral allergy symptoms, rhinitis, asthma or anaphylaxis in sensitised people. Occupational contact dermatitis from handling alliums is well documented in cooks and food handlers.

4. Bleeding and surgery. Garlic's antiplatelet effect is reasonably well documented and is the basis of standard advice to stop concentrated garlic supplements before surgery. Shallot-specific data is sparse, so this is extrapolation rather than evidence — but it is prudent extrapolation. Culinary amounts are not a concern. If you take a concentrated allium supplement, stop it one to two weeks before planned surgery and tell your surgical team.

5. Anticoagulants and antiplatelets. If you are on warfarin, a direct oral anticoagulant, clopidogrel or aspirin, culinary shallots are fine; concentrated allium supplements are worth clearing with your prescriber first, on the same extrapolated-from-garlic reasoning.

6. Botulism risk from alliums in oil. This one is not theoretical. Alliums stored in oil at room temperature create the anaerobic, low-acid conditions Clostridium botulinum requires, and garlic-in-oil has caused documented outbreaks. Home-made shallot oil or shallot confit must be refrigerated and used within a few days, or frozen. Do not leave a jar of shallots in oil on the counter.

7. Toxic to dogs and cats. All alliums — shallot, onion, garlic, leek, chive — cause oxidative damage to red blood cells in dogs and cats, producing Heinz-body haemolytic anaemia. Cats are especially sensitive. This includes cooked shallots, shallot powder, fried shallots and leftovers containing them. Do not share food seasoned with shallots with pets, and contact a vet if a pet eats a meaningful quantity.

8. Pregnancy and breastfeeding. Culinary amounts are safe and traditional worldwide. Concentrated extract supplements have no safety data in pregnancy and should be avoided. Strongly flavoured foods do pass into breast milk, which is normal and generally beneficial for infant taste development.

9. Species substitution in supplements. As covered above, "shallot" products may contain Persian shallot (Allium hirtifolium/stipitatum), a different species with a different chemistry and a different (small) evidence base. Read the Latin name on the label, and be aware that A. ascalonicum and A. cepa Aggregatum Group refer to the same plant while A. hirtifolium does not.

10. What shallots are not. They are not a treatment for high blood pressure, high cholesterol, diabetes, infection or cancer. They are an excellent, polyphenol-rich vegetable that makes food taste better, and the case for eating them is a food case, not a medical one.

Key Research Papers

  1. Yang J, Meyers KJ, van der Heide J, Liu RH. Varietal differences in phenolic content and antioxidant and antiproliferative activities of onions. Journal of Agricultural and Food Chemistry. 2004;52(22):6787–6793.
  2. Wiczkowski W, Romaszko J, Bucinski A, et al. Quercetin from shallots (Allium cepa L. var. aggregatum) is more bioavailable than its glucosides. The Journal of Nutrition. 2008;138(5):885–888.
  3. Major N, Perković J, Palčić I, et al. The phytochemical and nutritional composition of shallot species (Allium × cornutum, Allium × proliferum and A. cepa Aggregatum) is genetically and environmentally dependent. Antioxidants. 2022;11(8):1547.
  4. Nemeth K, Piskula MK. Food content, processing, absorption and metabolism of onion flavonoids. Critical Reviews in Food Science and Nutrition. 2007;47(4):397–409.
  5. Mullen W, Edwards CA, Crozier A. Absorption, excretion and metabolite profiling of methyl-, glucuronyl-, glucosyl- and sulpho-conjugates of quercetin in human plasma and urine after ingestion of onions. British Journal of Nutrition. 2006;96(1):107–116.
  6. Lee J, Mitchell AE. Pharmacokinetics of quercetin absorption from apples and onions in healthy humans. Journal of Agricultural and Food Chemistry. 2012;60(15):3874–3881.
  7. Chuljerm H, Nualsriwoa T, Iadnut A, et al. Protective effects of shallot (Allium ascalonicum) extracts against PAH-induced oxidative stress in human nasal epithelial cells. International Journal of Molecular Sciences. 2026;27(13):5855.
  8. Arpornchayanon W, Klinprung S, Chansakaow S, et al. Antiallergic activities of shallot (Allium ascalonicum L.) and its therapeutic effects in allergic rhinitis. Asian Pacific Journal of Allergy and Immunology. 2022;40(4):393–400.
  9. Wongmekiat O, Leelarugrayub N, Thamprasert K. Beneficial effect of shallot (Allium ascalonicum L.) extract on cyclosporine nephrotoxicity in rats. Food and Chemical Toxicology. 2008;46(5):1844–1850.
  10. Ratseewo J, Chumroenphat T, Li H, et al. Changes in chemical composition, volatile compound, and bioactive compounds retention in shallots (Allium ascalonicum L.) under different drying methods. Food Chemistry: X. 2025;27:102419.
  11. Mobin L, Haq MA, Ali R, et al. Antibacterial and antioxidant potential of the phenolic extract and its fractions isolated from Allium ascalonicum (onion) peel. Natural Product Research. 2022;36(12):3163–3167.
  12. Amin M, Kapadnis BP. Heat stable antimicrobial activity of Allium ascalonicum against bacteria and fungi. Indian Journal of Experimental Biology. 2005;43(8):751–754.
  13. Dankert J, Tromp TF, de Vries H, et al. Antimicrobial activity of crude juices of Allium ascalonicum, Allium cepa and Allium sativum. Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. 1979;245(1–2):229–239.

Live PubMed Searches

  1. Allium ascalonicum
  2. Allium cepa Aggregatum Group (shallot)
  3. Shallot quercetin bioavailability
  4. Onion flavonoids and cardiovascular outcomes
  5. Allium organosulfur and thiosulfinate chemistry
  6. Allium hirtifolium (Persian shallot)
  7. Fructans, FODMAPs and IBS
  8. Allium toxicity in dogs and cats
  9. Anthocyanins in red onion and shallot
  10. Allium compounds and Nrf2 induction

Connections

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