Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Full Spectrum Onion (Bulb) 400 mg Ingredients & Drug Interactions

by Swanson Premium Brand

Full Spectrum Onion (Bulb) 400 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Full Spectrum Onion (Bulb) 400 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Full Spectrum Onion (Bulb) 400 mg is a dietary supplement by Swanson Premium Brand with 1 active ingredient. Its ingredients are commonly taken for colds and respiratory symptoms, heart and cholesterol health, blood sugar support.Based on those ingredients, 275 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Onion. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand

Ask about any prescription or over-the-counter medication and we check it for interactions with Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 30, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: onion bulb at 400 mg per capsule in full-spectrum form, meaning it includes the whole plant material rather than an isolated extract. The capsule itself is made from gelatin and rice flour, which are inactive ingredients that hold the onion powder together.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded Onion's overall clinical evidence instead.

Moderate

Some clinical evidence supports Onion for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Scarring — rated "Possibly Effective" (Natural Medicines).

The evidence we have is thin. Onion shows possibly effective for scarring, but possibly ineffective for obesity.

For other uses — alopecia areata (patchy hair loss), angina (chest pain), and atherosclerosis (artery narrowing) — we don't have enough reliable evidence to rate it either way.

The evidence, ingredient by ingredient Onion

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Onion as food is generally well tolerated, but concentrated supplement doses haven't been as well studied, so the caution here is real. The most common side effects from taking it by mouth are abdominal pain and heartburn; some people have reported stomach distress or heartburn from onion powder, though it tends to be brief.

Rarely, onion can trigger anaphylaxis in people with a true onion allergy — and there are case reports of allergic reactions ranging from throat tightness to severe hives, and even migraines triggered by onion's smell. The safety data notes there isn't enough evidence on medicinal supplement doses to say they're entirely risk-free.

Side effects, ingredient by ingredient Onion

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Onion.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; lithium.
  • For scale: 275 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take this, double-check with your doctor or pharmacist if you're on blood thinners or antiplatelet drugs (a Moderate risk of increased bleeding), diabetes medications (a Moderate risk of low blood sugar), lithium (a Moderate risk of lithium buildup), or drugs metabolized by the liver enzyme CYP2E1. Also, if you take aspirin and have an onion allergy, the combination may worsen allergic reactions.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This is a single-ingredient supplement that might be worth a try if you're interested in onion for scarring, but the evidence for most other uses just isn't there yet. If you take blood thinners, diabetes medications, lithium, or have an onion allergy, you'll want to talk it over with your doctor or pharmacist before starting.

Even if you don't take any of those, your own healthcare provider can help you decide if a concentrated onion supplement makes sense for you.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated May 24, 2018.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Full Spectrum Onion (Bulb) 400 mg, straight from the product label.

Brand Swanson Premium Brand
Barcode (UPC) 087614112640
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD May 24, 2018
DSLD ID 177130
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
087614112640
IngredientAmount% DV
Onion400 mg--

Other ingredients: Gelatin, Rice Flour, May contain one or both of the following

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Bringing wellness to the world since 1969

To reorder, call toll free 1-800-437-4148 or visit our website at www.swansonvitamins.com

FDA Statement of Identity

Herbal Supplement

Seals/Symbols

Guaranteed purity & potency

Precautions

Do not use if seal is broken.

Keep out of reach of children.

Storage

Store in a cool, dry place.

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take one capsule one to two times per day with water.

General

SW1264 Rev 0 09 22 17

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Full Spectrum Onion (Bulb) 400 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Onion

Interacts with
275 drugs
400 mg per serving

Onion is a common food with a long history in traditional medicine, and it contains antioxidants like quercetin and sulfur compounds. Eating onion as...

Onion monograph & interactions

Other (inactive) ingredients: Gelatin, Rice Flour, May contain one or both of the following. These complete the product’s ingredient list but are not active constituents.

Interaction report

Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand Drug Interactions

Want to check YOUR meds against Full Spectrum Onion (Bulb) 400 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
275Drugs
275 Moderate

Ingredients driving the most interactions

Onion 275

Individual Drug Interactions

The ingredients in Full Spectrum Onion (Bulb) 400 mg interact with 275 drugs. Click any drug to see the details.

1 of the 1 ingredient in Full Spectrum Onion (Bulb) 400 mg interact with drugs. Each result below shows which ingredient is responsible. Onion

Each ingredient & the kinds of drugs it affects

For each ingredient in Full Spectrum Onion (Bulb) 400 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Onion5 drug types · 275 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, concomitant use of anticoagulant or antiplatelet drugs with onion might increase the risk of bleeding.
In vitro research shows that onion inhibits platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Concomitant use of antidiabetes drugs with onion may increase the risk of hypoglycemia.
Animal research and clinical research shows that taking onion can lower blood glucose levels. Monitor blood glucose levels closely.

Likelihood Possible Evidence B
Aspirin

Concomitant use of aspirin with onion may worsen onion allergy.
In one case report, a patient with a mild onion allergy reported worsening allergy, including swelling and severe urticaria, after taking aspirin.

Likelihood Probable Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, taking onion might increase the levels and clinical effects of drugs metabolized by CYP2E1.
Animal research shows that taking onion powder inhibits CYP2E1. However, this interaction has not been reported in humans.

Likelihood Possible Evidence B
Lithium

Onion is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, onion might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Onion full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Full Spectrum Onion (Bulb) 400 mg, from the product label.

Swanson Premium Brand

See all Swanson Premium Brand products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
www.swansonvitamins.com
Pharmacist Counseling Corner

Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand: Common Questions

Does Full Spectrum Onion (Bulb) 400 mg by Swanson Premium Brand interact with any medications?
Yes. Based on its ingredients, Full Spectrum Onion (Bulb) 400 mg has a known interaction with 275 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Full Spectrum Onion (Bulb) 400 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm on aspirin?
If you have a mild onion allergy, aspirin and onion together may make allergic symptoms worse — swelling and hives have been reported. If you don't have an onion allergy, the data we hold doesn't flag aspirin use as a barrier, but talk it over with your doctor or pharmacist to be sure.
What are the most common side effects?
Abdominal pain and heartburn are the most common. Some people report stomach distress, which usually passes quickly. Rarely, onion can trigger a serious allergic reaction like anaphylaxis in people with a true onion allergy.
Is this safe to take while pregnant or breastfeeding?
The facts on file don't include pregnancy or breastfeeding safety data for this product, so there isn't enough information to know either way. Talk with your doctor or pharmacist about whether it's right for you in that situation.
Does onion actually work for weight loss?
No — the evidence shows onion is possibly ineffective for obesity. There are better-studied options if weight loss is your goal.
What is full-spectrum onion?
Full-spectrum means the supplement contains the whole onion bulb material rather than a single isolated compound extracted from it. It's meant to give you the onion as close to its natural form as possible.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Full Spectrum Onion (Bulb) 400 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Full Spectrum Onion (Bulb) 400 mg label
Go deeper

The Full Monographs Behind Full Spectrum Onion (Bulb) 400 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Onion

Interacts with 275 drugs

Onion is a common food with a long history in traditional medicine, and it contains antioxidants like quercetin and sulfur compounds. Eating onion as part of a balanced diet is safe for most...

Read the full Onion monograph →
Sources

Sources & How We Checked

Full Spectrum Onion (Bulb) 400 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 26 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Onion 26 references
  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Bruynzeel DP. Bulb dermatitis. Dermatological problems in the flower bulb industries. Contact Dermatitis 1997;37:70-7.
  4. Eberhard P, Gall HM, Muller I, Moller R. Dramatic augmentation of a food allergy by acetylsalicylic acid. J Allergy Clin Immunol 2000;105:844 PubMed
  5. Teyssier, C., Amiot, M. J., Mondy, N., Auger, J., Kahane, R., and Siess, M. H. Effect of onion consumption by rats on hepatic drug-metabolizing enzymes. Food Chem.Toxicol. 2001;39(10):981-987. PubMed
  6. Moneret-Vautrin, D. A., Morisset, M., Lemerdy, P., Croizier, A., and Kanny, G. Food allergy and IgE sensitization caused by spices: CICBAA data (based on 589 cases of food allergy). Allerg.Immunol.(Paris) 2002;34(4):135-140.
  7. van Ketel, W. G. and de Haan, P. Occupational eczema from garlic and onion. Contact Dermatitis 1978;4(1):53-54. PubMed
  8. Mathew, P. T. and Augusti, K. T. Hypoglycaemic effects of onion, Allium cepa Linn. on diabetes mellitus - a preliminary report. Indian J.Physiol Pharmacol. 1975;19(4):213-217.
  9. Campos, K. E., Diniz, Y. S., Cataneo, A. C., Faine, L. A., Alves, M. J., and Novelli, E. L. Hypoglycaemic and antioxidant effects of onion, Allium cepa: dietary onion addition, antioxidant activity and hypoglycaemic effects on diabetic rats. Int J Food S
  10. Bajaj, J. S., Shaker, R., and Hogan, W. J. Esophageal veggie spasms: a food-specific cause of chest distress. Am.J Gastroenterol. 2004;99(7):1396-1398. PubMed
  11. El Demerdash, F. M., Yousef, M. I., and El Naga, N. I. Biochemical study on the hypoglycemic effects of onion and garlic in alloxan-induced diabetic rats. Food Chem.Toxicol. 2005;43(1):57-63. PubMed
  12. Hubbard, G. P., Wolffram, S., de Vos, R., Bovy, A., Gibbins, J. M., and Lovegrove, J. A. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pil
  13. Kook, S., Kim, G. H., and Choi, K. The antidiabetic effect of onion and garlic in experimental diabetic rats: meta-analysis. J Med Food 2009;12(3):552-560. PubMed
  14. Sharma, K. K., Gupta, R. K., Gupta, S., and Samuel, K. C. Antihyperglycemic effect of onion: effect on fasting blood sugar and induced hyperglycemia in man. Indian J.Med.Res. 1977;65(3):422-429.
  15. Jain, R. C., Vyas, C. R., and Mahatma, O. P. Letter: Hypoglycaemic action of onion and garlic. Lancet 12-29-1973;2(7844):1491.
  16. Jain, R. C. and Vyas, C. R. Letter: Hypoglycaemia action of onion on rabbits. Br.Med.J. 6-29-1974;2(5921):730. PubMed
  17. Veien, N. K., Hattel, T., Justesen, O., and Norholm, A. Causes of eczema in the food industry. Derm.Beruf.Umwelt. 1983;31(3):84-86.
  18. Tjokroprawiro, A., Pikir, B. S., Budhiarta, A. A., Pranawa, Soewondo, H., Donosepoetro, M., Budhianto, F. X., Wibowo, J. A., Tanuwidjaja, S. J., Pangemanan, M., and . Metabolic effects of onion and green beans on diabetic patients. Tohoku J Exp Med 1983; PubMed
  19. Brenner, S. and Wolf, R. Possible nutritional factors in induced pemphigus. Dermatology 1994;189(4):337-339. PubMed
  20. Roussos AP, Hirsch AR. Alliaceous migraines. Headache 2014;54(2):378-82. PubMed
  21. Akash MS, Rehman K, Chen S. Spice plant Allium cepa: dietary supplement for treatment of type 2 diabetes mellitus. Nutrition 2014;30(10):1128-37. PubMed
  22. 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 PubMed
  23. Eldin IM, Ahmed EM, HM AE. Preliminary study of the clinical hypoglycemic effects of Allium cepa (red onion) in type 1 and type 2 diabetic patients. Environmental health insights 2010;4:71. PubMed
  24. Albanesi M, Pasculli C, Giliberti L, et al. Immunological characterization of onion (Allium cepa) allergy. Postepy Dermatol Alergol. 2019;36(1):98-103. PubMed
  25. Armentia A, Martín-Armentia S, Pineda F, et al. Allergic hypersensitivity to garlic and onion in children and adults. Allergol Immunopathol (Madr). 2019. pii: S0301-0546(19)30091-6. PubMed
  26. Nishimura M, Muro T, Kobori M, Nishihira J. Effect of daily ingestion of quercetin-rich onion powder for 12 weeks on visceral fat: A randomised, double-Blind, placebo-controlled, parallel-group study. Nutrients. 2019 Dec 28;12(1):91. PubMed

See these in context on the Onion monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team