Skip to Content


Scientific Name(s): Allium cepa L.
Common Name(s): Bulbus Allii Cepae, Common onion, Contractubex, Garden onion, Mederma, Onion

Clinical Overview


Onion has potential in treating cardiovascular disease (eg, atherosclerosis), osteoporosis, and certain cancers; however, few quality clinical trials are available to support these uses. Topical preparations have been evaluated for the prevention of surgical scarring with varying results.


Onion-based quercetin 100 to 500 mg per day has been used in limited clinical studies. Average daily doses of 50 g of fresh onion, or 20 g of dried onion have been suggested. Topical onion extract gels have been used in studies evaluating effects on scarring and are generally applied 3 times daily.


Contraindications have not been identified.


Onion has "generally recognized as safe" (GRAS) status when used as food. Avoid amounts greater than those found in foods because safety has not been established.


None well documented.

Adverse Reactions

Few reported.


No data.


The onion plant is a perennial herb growing to about 1.2 m in height, with 4 to 6 hollow, cylindrical leaves. On top of the long stalks, greenish-white flowers in the form of solitary umbels grow to 2.5 cm wide. The seeds of the plant are black and angular. The underground bulb, which is used medicinally and consumed as food, is comprised of fleshy leaf sheaths forming a thin-skinned capsule and varies greatly in size (2 to 20 cm). The shape (flattened, spherical, or pear shaped) and color of the bulb depends on the variety.Blumenthal 1998, Suleria 2015, USDA 2018, WHO 1999


The onion is one of the world's leading vegetable crops, believed to have been domesticated in central and western Asia. Onions were used as early as 5,000 years ago in Egypt, and are depicted on ancient monuments; ancient Greek and Roman records also make references to the onion. Onions were consumed throughout Europe during the Middle Ages and were later thought to guard against evil spirits and the plague, probably because of their strong odor. Folk healers traditionally used onions to prevent infections, and an onion and garlic concoction cooked in milk was used as a European folk remedy for congestion. Onion skin dye has also been used for egg and cloth coloring in the Middle East and Europe. Christopher Columbus is said to have introduced the plant to North America on his 1492 expedition. Onions are routinely used in homeopathic medicine.Blumenthal 1998, Lanzotti 2006, WHO 1999


Onions contain 89% water, 1.5% protein, and vitamins B1, B2, and C, along with potassium and selenium. Polysaccharides such as fructosans, saccharose, and others are also present, as are peptides, flavonoids (mostly quercetin), and essential oil. Methods for the qualitative assessment of the flavonoids have been detailed, and quercetin glycosides have been shown to be heat stable and transferable to cooking water.

Onion contains numerous sulfur compounds, including thiosulfinates and thiosulfonates; cepaenes; S-oxides; S,S-dioxides; mono-, di-, and trisulfides; and sulfoxides. When the onion bulb is minced or crushed, cysteine sulfoxides are released from cellular compartments and make contact with the enzyme alliinase from the adjacent vacuoles. Hydrolysis results in the release of reactive intermediate sulfenic acid compounds and then the various sulfur compounds.Arnault 2006, Blumenthal 1998, Graefe 2001, Lanzotti 2006, Nemeth 2007, Rose 2005, WHO 1999, Wiczkowski 2008

Uses and Pharmacology

Anti-inflammatory effects

Animal and in vitro data

Compounds derived from onion have exerted anti-inflammatory and antihistamine effects in vitro and in animal models.Griffiths 2002, WHO 1999

Antimicrobial effects

In vitro data

In vitro studies have shown onion possesses antibacterial (including against Helicobacter pylori), antiparasitic, and antifungal activity.Elnima 1983, Rose 2005, USDA 2018, Zohri 1995 Clinical applications for this activity have not been determined, and use as a food preservative is limited by the strong odor and instability of sulfur compounds.Griffiths 2002


Animal and in vitro data

In vitro and animal model studies describe inhibition of mutagenesis, modulation of enzyme and cell signaling pathways, free-radical scavenging, apoptosis, and other effects on cell proliferation and tumor growth.Bianchini 2001, Boyle 2000, Fukushima 1997, Herman-Antosiewicz 2004, Izawa 2008, Munday 2004, Nohara 2017, Rose 2005

Clinical data

Large epidemiological studies infer a protective effect of onion (as well as garlic and leek) consumption against stomach and colorectal cancers.Bianchini 2001, Griffiths 2002, Rose 2005 Case-control (retrospective) data also suggest an inverse relationship between onion consumption and benign prostatic hypertrophy and endometrial cancer.Galeone 2009, Galeone 2007, Suleria 2015 An overestimation of effect for stomach and colorectal cancers is possible due to publication and recall bias, and insufficient evidence exists for breast, lung, and other cancers.Bianchini 2001, Challier 1998, Griffiths 2002, Rose 2005 In the case of GI-related cancers, proposed mechanisms of action for the Allium species include inhibition of H. pylori and other bacterial activity, as well as general decreases in endogenous production of carcinogenic N-nitroso compounds.Bianchini 2001, Griffiths 2002

Prospective clinical trials are lacking.Nicastro 2015

In a study of women with breast cancer undergoing doxorubicin-based chemotherapy, reductions in tumor markers and hepatic enzymes were demonstrated with 100 to 160 g/day of fresh yellow onion for 8 weeks versus a low-onion (30 to 40 g/day) comparator group.Jafarpour 2015

Cardiovascular disease/Atherosclerosis

Quercetin, onion extract, and onion soup have been evaluated in vitro and in vivo for effects on platelet aggregation in limited studies with mixed results.Griffiths 2002, Hubbard 2006, Hubbard 2004, WHO 1999

Animal data and in vitro data

Hypolipidemic effects of onion sulfur compounds, including S-methyl cysteine sulfoxide and allyl propyl disulfide, have been demonstrated in rats and rabbits, and include effects on diet-induced atherosclerosis, hypolipidemic action, and inhibitory effects on platelet formation. Raw, but not cooked, onion demonstrated antithrombotic effects in rats.Bordia 1996, Chen 2000, Kumari 1995, Lata 1991, Tang 2017, Wilcox 1984

Studies evaluating certain onion genotypes show that those containing higher sulfur content in the bulb correlate with greater antiplatelet activity. Thiosulfinates dimethyl- and diphenyl-thiosulfinate, for example, are known to slow thrombocyte biosynthesis. The least polar fraction of onion extract was associated with the most inhibitory activity against platelet aggregation; thus, a greater inhibition of thromboxane synthesis was reported.Goldman 1996, Griffiths 2002, Miller 1998

Clinical data

Trials have generally been conducted in small populations, and limited substantial evidence supporting claims of cardiovascular benefits exists.

In a clinical trial evaluating raw red onion consumption on metabolic features in overweight or obese women with polycystic ovary syndrome, total cholesterol and low-density lipoprotein cholesterol decreased compared with the control group. Other measures were unaffected.Ebrahimi 2014

In a study on endothelial function (n=72), onion peel extract (quercetin 100 mg/day administered for 12 weeks) improved flow-mediated dilation and circulating endothelial progenitor cells versus placebo.Choi 2015

Other studies have reported equivocal results for effects on hyperlipidemia.McAnlis 1999, O'Reilly 2001, Rose 2005

Dermatological effects

In vitro data

Inhibition of human skin fibroblasts and keloidal fibroblasts has been demonstrated in vitro.WHO 1999

Clinical data

Limited clinical trials evaluating the effects of onion extract gels on scarring have demonstrated equivocal results. In certain populations, reductions in redness, itching, burning, and pain associated with surgical procedures have been demonstrated,Draelos 2008, Ho 2006, Jackson 1999, Koc 2008 while in other populations, there was no difference over standard petroleum-based emollient therapy.Chung 2006, Koc 2008


Animal data

Hypoglycemic effects of onion extracts have been demonstrated in animal models.Akash 2014, Kook 2009, Roman-Ramos 1995, Sheela 1995, WHO 1999

Clinical data

Quality clinical trials are lacking; and limited trials have reported equivocal results. Some studies show decreases in blood glucose levels in healthy volunteers and non-insulin–dependent diabetic subjects with aqueous onion extract and raw dietary onion.Akash 2014, Griffiths 2002, WHO 1999

Glucose metabolism was not affected by supplemental quercetin (162 mg/day over 6 weeks from onion skin extract powder) in one clinical trial (N=70) evaluating the effect of quercetin on cardiovascular biomarkers.Brull 2015 In a similar study by the same researchers, postprandial metabolic and vascular responses induced by a high-fat and high-carbohydrate meal were not attenuated by ingestion of quercetin.Brull 2017

The levels of fasting blood sugar were unaffected in a trial evaluating effects of raw red onion consumption on metabolic features in overweight or obese women with polycystic ovary syndrome.Ebrahimi 2014


Clinical data

Findings from a clinical study suggest quercetin supplementation (500 mg/day for 4 weeks) reduces elevated plasma uric acid concentrations in healthy males.Shi 2016


Clinical data

In one study, quercetin, but not raw onion, decreased blood pressure (BP) in hypertensive subjects.Edwards 2007

In a subgroup analysis of hypertensive subjects using supplemental quercetin 162 mg/day over 6 weeks (from onion skin extract powder), 24-hour systolic BP was reduced by −3.6 mm Hg (P=0.022) compared with placebo (mean treatment difference, −3.9 mm Hg; P=0.049). Hypertension was unaffected in the total group analysis (N=70 overweight to obese patients with prehypertension and stage I hypertension), and other biomarkers of cardiovascular disease and glucose metabolism were not affected by quercetin.Brull 2015

In a similar study by the same researchers, postprandial metabolic and vascular responses induced by a high-fat and high-carbohydrate meal were also not attenuated by ingestion of quercetin.Brull 2017


In vitro data

Studies evaluating inhibitory effects on the differentiation of osteoclasts in the cell line indicate that onion extract effectively inhibits osteoclastogenesis and differentiation.Law 2016

Clinical data

A study evaluating the impact of onion juice intake on bone mineral density and bone loss in corroboration with antioxidant effects in middle-aged, postmenopausal healthy subjects showed a positive modulatory effect on bone loss and bone mineral density due to improvement in antioxidant activity.Law 2016


An average daily dose of 50 g of fresh onion, or 20 g of dried onion has been suggested for a variety of uses.Blumenthal 1998, WHO 1999

Pharmacokinetic studies in rodents and healthy participants suggest greater bioavailability of quercetin from onion powder over apple peel,Lee 2012 of fresh red onion over dietary supplementation (aglycone quercetin),Shi 2015 of onion peel powder over onion peel extract,Kashino 2015 and of onion skin extract over pure quercetin dihydrate powder–filled hard capsules.Burak 2017

Based on a study in healthy adult males, it has been suggested that supplemental quercetin 166 mg would be comparable to about 10 mg of quercetin aglycone equivalent from red onion (in soup).Shi 2015

Cardiovascular disease/atherosclerosis

Onion peel extract (quercetin 100 mg/day for 12 weeks) has been used in a study evaluating effects on endothelial function.Choi 2015

Dermatological use

Topical onion extract gels have been used in studies evaluating effects on scarring and are generally applied 3 times daily.Chung 2006, Koc 2008


Quercetin 500 mg/day for 4 weeks (bioavailable amount of quercetin present in approximately 100 g of red onions) has been studied for treatment of hyperuricemia.Shi 2016


Supplemental quercetin 162 mg/day over 6 weeks (from onion skin extract powder) has been studied for treatment of hypertension.Brull 2015

Pregnancy / Lactation

Onion has GRAS status when used as food. Avoid amounts greater than those found in foods because safety has not been established.


None well documented. No potentiation of antiplatelet effects has been reported.

Adverse Reactions

Ingestion of onion and onion extract appears to be relatively safe.Blumenthal 1998, WHO 1999 Excessive consumption of onion has been associated with GI upset (burning sensation and diarrhea), flatulence, and changes in intestinal flora.Suleria 2015

Onion seeds have been reported as occupational allergens, but frequent contact with onion rarely causes allergic reaction.Navarro 1995 Certain sulfur compounds, such as propanethial-S-oxide, escape from onion in vapor form and hydrolyze to sulfuric acid when cut, causing eye irritation and lacrimation.Chan 1972 Using a sharp knife minimizes the crushing of onion tissue and liberation of volatiles, and cutting an onion under running water reduces lacrimation.


Mutagenicity of Bulbus Allii Cepae was not demonstrated in vitro.WHO 1999 Low doses of onion (50 mg/kg) given to rats had little effect on lung and liver tissues, but high doses (500 mg/kg) resulted in histological changes in these organs. Intraperitoneal administration was more damaging than oral administration, resulting in 25% mortality in rats.Thomson 1998 Poisoning in cattle fed large quantities of onion has been reported.Verhoeff 1985 Food colorant extracted from the tan onion bulb covering had no acute or subacute toxic effects in mice.Kojima 1993


Akash MS, Rehman K, Chen S. Spice plant Allium cepa: dietary supplement for treatment of type 2 diabetes mellitus. Nutrition. 2014;30(10):1128-1137.25194613
Arnault I, Auger J. Seleno-compounds in garlic and onion. J Chromatogr A. 2006;1112(1-2):23-30.16480995
Bianchini F, Vainio H. Allium vegetables and organosulfur compounds: do they help prevent cancer? Environ Health Perspect. 2001;109(9):893-902.11673117
Blumenthal M, Busse WR, Goldberg A, eds. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin, TX: American Botanical Council; 1998.
Bordia T, Mohammed N, Thomson M, Ali M. An evaluation of garlic and onion as antithrombotic agents. Prostaglandins Leukot Essent Fatty Acids. 1996;54(3):183-186.8860105
Boyle SP, Dobson VL, Duthie SJ, Kyle JA, Collins AR. Absorption and DNA protective effects of flavonoid glycosides from an onion meal. Eur J Nutr. 2000;39(5):213-223.11131368
Brüll V, Burak C, Stoffel-Wagner B, et al. Acute intake of quercetin from onion skin extract does not influence postprandial blood pressure and endothelial function in overweight-to-obese adults with hypertension: a randomized, double-blind, placebo-controlled, crossover trial. Eur J Nutr. 2017;56(3):1347-1357.26924303
Brüll V, Burak C, Stoffel-Wagner B, et al. Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial. Br J Nutr. 2015;114(8):1263-1277.26328470
Burak C, Brüll V, Langguth P, et al. Higher plasma quercetin levels following oral administration of an onion skin extract compared with pure quercetin dihydrate in humans. Eur J Nutr. 2017;56(1):343-353.26482244
Challier B, Perarnau JM, Viel JF. Garlic, onion and cereal fibre as protective factors for breast cancer: a French case-control study. Eur J Epidemiol. 1998;14(8):737-747.9928867
Chan RS, Mandell RB. Corneal swelling caused by Allium cepa. Am J Optom Arch Am Acad Optom. 1972;49(9):713-715.4507457
Chen JH, Chen HI, Tsai SJ, Jen CJ. Chronic consumption of raw but not boiled Welsh onion juice inhibits rat platelet function. J Nutr. 2000;130(1):34-37.10613763
Choi EY, Lee H, Woo JS, et al. Effect of onion peel extract on endothelial function and endothelial progenitor cells in overweight and obese individuals. Nutrition. 2015;31(9):1131-1135.26233871
Chung VQ, Kelley L, Marra D, Jiang SB. Onion extract gel versus petrolatum emollient on new surgical scars: prospective double-blinded study. Dermatol Surg. 2006;32(2):193-197.16442038
Draelos ZD. The ability of onion extract gel to improve the cosmetic appearance of postsurgical scars. J Cosmet Dermatol. 2008;7(2):101-104.18482012
Ebrahimi-Mamaghani M, Saghafi-Asl M, Pirouzpanah S, Asghari-Jafarabadi M. Effects of raw red onion consumption on metabolic features in overweight or obese women with polycystic ovary syndrome: a randomized controlled clinical trial. J Obstet Gynaecol Res. 2014;40(4):1067-1076.24612081
Edwards RL, Lyon T, Litwin SE, Rabovsky A, Symons JD, Jalili T. Quercetin reduces blood pressure in hypertensive subjects. J Nutr. 2007;137(11):2405-2411.17951477
Elnima EI, Ahmed SA, Mekkawi AG, Mossa JS. The antimicrobial activity of garlic and onion extracts. Pharmazie. 1983;38(11):747-748.6669596
Fukushima S, Takada N, Hori T, Wanibuchi H. Cancer prevention by organosulfur compounds from garlic and onion. J Cell Biochem Suppl. 1997;27:100-105.9591199
Galeone C, Pelucchi C, Dal Maso L, et al. Allium vegetables intake and endometrial cancer risk. Public Health Nutr. 2009;12(9):1576-1579.18986589
Galeone C, Pelucchi C, Talamini R, et al. Onion and garlic intake and the odds of benign prostatic hyperplasia. Urology. 2007;70(4):672-676.17991535
Goldman IL, Kopelberg M, Debaene JE, Schwartz BS. Antiplatelet activity in onion (Allium cepa) is sulfur dependent. Thromb Haemost. 1996;76(3):450-452.8883285
Graefe EU, Wittig J, Mueller S, et al. Pharmacokinetics and bioavailability of quercetin glycosides in humans. J Clin Pharmacol. 2001;41(5):492-499.11361045
Griffiths G, Trueman L, Crowther T, Thomas B, Smith B. Onions—a global benefit to health. Phytother Res. 2002;16(7):603-615.12410539
Herman-Antosiewicz A, Singh SV. Signal transduction pathways leading to cell cycle arrest and apoptosis induction in cancer cells by Allium vegetable-derived organosulfur compounds: a review. Mutat Res. 2004;555(1-2):121-131.15476856
Ho WS, Ying SY, Chan PC, Chan HH. Use of onion extract, heparin, allantoin gel in prevention of scarring in chinese patients having laser removal of tattoos: a prospective randomized controlled trial. Dermatol Surg. 2006;32(7):891-896.16875470
Hubbard GP, Wolffram S, de Vos R, Bovy A, Gibbins JM, Lovegrove JA. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study. Br J Nutr. 2006;96(3):482-488.16925853
Hubbard GP, Wolffram S, Lovegrove JA, Gibbins JM. Ingestion of quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in humans. J Thromb Haemost. 2004;2(12):2138-2145.15613018
Izawa H, Kohara M, Aizawa K, et al. Alleviative effects of quercetin and onion on male reproductive toxicity induced by diesel exhaust particles. Biosci Biotechnol Biochem. 2008;72(5):1235-1241.18460802
Jackson BA, Shelton AJ. Pilot study evaluating topical onion extract as treatment for postsurgical scars. Dermatol Surg. 1999;25(4):267-269.10417579
Jafarpour-Sadegh F, Montazeri V, Adili A, et al. Effects of fresh yellow onion consumption on CEA, CA125 and hepatic enzymes in breast cancer patients: A double-blind randomized controlled clinical trial. Asian Pac J Cancer Prev. 2015;16(17):7517-7522.26625755
Kashino Y, Murota K, Matsuda N, et al. Effect of processed onions on the plasma concentration of quercetin in rats and humans. J Food Sci. 2015;80(11):H2597-H2602.26375490
Koc E, Arca E, Surucu B, Kurumlu Z. An open, randomized, controlled, comparative study of the combined effect of intralesional triamcinolone acetonide and onion extract gel and intralesional triamcinolone acetonide alone in the treatment of hypertrophic scars and keloids. Dermatol Surg. 2008;34(11):1507-1514.18798752
Kojima T, Tanaka T, Mori H, Kato Y, Nakamura M. Acute and subacute toxicity tests of onion coat, natural colorant extracted from onion (Allium cepa L.), in (C57BL/6 × C3H)F1 mice. J Toxicol Environ Health. 1993;38(1):89-101.8421325
Kook S, Kim GH, Choi K. The antidiabetic effect of onion and garlic in experimental diabetic rats: meta-analysis. J Med Food. 2009;12(3):552-560.19627203
Kumari K, Mathew BC, Augusti KT. Antidiabetic and hypolipidemic effects of S-methyl cysteine sulfoxide isolated from Allium cepa Linn [published correction appears in Indian J Biochem Biophys. 1995;32(2):111]. Indian J Biochem Biophys. 1995;32(1):49-54.7665195
Lanzotti V. The analysis of onion and garlic. J Chromatogr A. 2006;1112(1-2):3-22.16388813
Lata S, Saxena KK, Bhasin V, Saxena RS, Kumar A, Srivastava VK. Beneficial effects of Allium sativum, Allium cepa and Commiphora mukul on experimental hyperlipidemia and atherosclerosis—a comparative evaluation. J Postgrad Med. 1991;37(3):132-135.1784023
Law YY, Chiu HF, Lee HH, Shen YC, Venkatakrishnan K, Wang CK. Consumption of onion juice modulates oxidative stress and attenuates the risk of bone disorders in middle-aged and post-menopausal healthy subjects. Food Funct. 2016;7(2):902-912.26686359
Lee J, Mitchell AE. Pharmacokinetics of quercetin absorption from apples and onions in healthy humans. J Agric Food Chem. 2012;60(15):3874-3881.22439822
McAnlis GT, McEneny J, Pearce J, Young IS. Absorption and antioxidant effects of quercetin from onions, in man. Eur J Clin Nutr. 1999;53(2):92-96.10099940
Miller LG, Murray WJ, eds. Herbal Medicinals, A Clinician's Guide. New York: Pharmaceutical Products Press; 1998:195-202.
Munday R, Munday CM. Induction of phase II enzymes by aliphatic sulfides derived from garlic and onions: an overview. Methods Enzymol. 2004;382:449-456.15047116
Navarro JA, del Pozo MD, Gastaminza G, Moneo I, Audícana MT, Fernández de Corres L. Allium cepa seeds: a new occupational allergen. J Allergy Clin Immunol. 1995;96(5, pt 1):690-693.7499687
Nemeth K, Piskula MK. Food content, processing, absorption and metabolism of onion flavonoids. Crit Rev Food Sci Nutr. 2007;47(4):397-409.17457724
Nicastro HL, Ross SA, Milner JA. Garlic and onions: their cancer prevention properties. Cancer Prev Res (Phila). 2015;8(3):181-189.25586902
Nohara T, Fujiwara Y, El-Aasr M, et al. Antitumor allium sulfides. Chem Pharm Bull (Tokyo). 2017;65(3):209-217.28250342
O'Reilly JD, Mallet AI, McAnlis GT, et al. Consumption of flavonoids in onions and black tea: lack of effect on F2-isoprostanes and autoantibodies to oxidized LDL in healthy humans. Am J Clin Nutr. 2001;73(6):1040-1044.11382657
Roman-Ramos R, Flores-Saenz JL, Alarcon-Aguilar FJ. Anti-hyperglycemic effect of some edible plants. J Ethnopharmacol. 1995;48(1):25-32.8569244
Rose P, Whiteman M, Moore PK, Zhu YZ. Bioactive S-alk(en)yl cysteine sulfoxide metabolites in the genus Allium: the chemistry of potential therapeutic agents. Nat Prod Rep. 2005;22(3):351-368.16010345
Sheela CG, Kumud K, Augusti KT. Anti-diabetic effects of onion and garlic sulfoxide amino acids in rats. Planta Med. 1995;61(4):356-357.7480182
Shi Y, Williamson G. Comparison of the urinary excretion of quercetin glycosides from red onion and aglycone from dietary supplements in healthy subjects: a randomized, single-blinded, cross-over study. Food Funct. 2015;6(5):1443-1448.25832541
Shi Y, Williamson G. Quercetin lowers plasma uric acid in pre-hyperuricaemic males: a randomised, double-blinded, placebo-controlled, cross-over trial. Br J Nutr. 2016;115(5):800-806.26785820
Suleria HA, Butt MS, Anjum FM, Saeed F, Khalid N. Onion: nature protection against physiological threats. Crit Rev Food Sci Nutr. 2015;55(1):50-66.24915405
Tang GY, Meng X, Li Y, Zhao CN, Liu Q, Li HB. Effects of vegetables on cardiovascular diseases and related mechanisms. Nutrients. 2017;9(8). pii: E857.28796173
Thomson M, Alnaqeeb MA, Bordia T, Al-Hassan JM, Afzal M, Ali M. Effects of aqueous extract of onion on the liver and lung of rats. J Ethnopharmacol. 1998;61(2):91-99.9683339
Allium cepa L. USDA, NRCS. 2018. The PLANTS Database (, April 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA. Accessed April 2018.
Verhoeff J, Hajer R, van den Ingh TS. Onion poisoning of young cattle. Vet Rec. 1985;117(19):497-498.4082398
Bulbus Allii Cepae. In: WHO Monographs on Selected Medicinal Plants. Vol. 1. Geneva, Switzerland: World Health Organization; 1999:5.
Wiczkowski W, Romaszko J, Bucinski A, et al. Quercetin from shallots (Allium cepa L. var. aggregatum) is more bioavailable than its glucosides. J Nutr. 2008;138(5):885-888.18424596
Wilcox BF, Joseph PK, Augusti KT. Effects of allylpropyl disulphide isolated from Allium cepa Linn on high-fat fed rats. Indian J Biochem Biophys. 1984;21(3):214-216.6519679
Zohri AN, Abdel-Gawad K, Saber S. Antibacterial, antidermatophytic and antitoxigenic activities of onion (Allium cepa L.) oil. Microbiol Res. 1995;150(2):167-172.7600010


This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

More about onion

Consumer resources

Related treatment guides