Interactions on record — worth a quick check against your medications. Based on 2 of 3 ingredients. Check your meds →
Dietary supplement

Barley Grass 500 mg Ingredients & Drug Interactions

by Thompson

Tablet Or Pill Category: Botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Barley Grass 500 mg is a dietary supplement by Thompson with 3 active ingredients. Its ingredients are commonly taken for constipation, diarrhea, high cholesterol.Based on those ingredients, 2,025 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Dietary Fiber, organic Barley. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Barley Grass 500 mg by Thompson

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

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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product has one active ingredient: organic barley at 500 mg per tablet. The inactive ingredients are cellulose, magnesium stearate, and silica — standard tablet binders and flow agents.

Barley is a whole grain that's been used as both a food and a supplement. In this concentrated form, you're getting the nutrient profile of barley in a single dose.

Does it work?

Strong 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 its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients 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 ingredients' overall clinical evidence instead.
  • On file: Constipation — rated "Effective" (Black Psyllium) (Natural Medicines).
  • On file: Coronary heart disease (CHD) — rated "Likely Effective" (Black Psyllium) (Natural Medicines).
  • On file: Hypercholesterolemia — rated "Likely Effective" (Barley) (Natural Medicines).

Barley has strong evidence behind it for two uses: it's likely effective for lowering cholesterol (hypercholesterolemia) and for supporting heart health in coronary heart disease. The data we hold doesn't establish effectiveness for other conditions, though barley has been studied for various other uses.

The evidence, ingredient by ingredient Black Psyllium Barley

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Barley as a food is well tolerated and safe for most people. The supplement form, though, hasn't been studied as thoroughly — especially in pregnancy and while breastfeeding.

The main caution is that barley contains gluten, which can trigger reactions in people with celiac disease or gluten sensitivity. Common side effects from barley supplements are mild: bloating, gas, abdominal distension, and an unpleasant taste.

Allergic reactions are rare but possible in sensitive individuals — symptoms can range from tingling around the mouth and lips to angioedema (swelling under the skin), hives, chest tightness, shortness of breath, and in severe cases, anaphylaxis. If you have a history of cereal allergies or asthma triggered by grain dusts, mention this before starting.

Side effects, ingredient by ingredient Black Psyllium Barley

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?
  • 2 of the 2 matched ingredients can interact with medications — Black Psyllium, Barley.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: heart-rhythm medications; lithium.
  • For scale: 2,026 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.

Check with your pharmacist before taking this if you're on triclabendazole (Egaten), an antiparasitic medication — barley may reduce how well it works. No other medication interactions are documented for the ingredients we could check.

Check your own medication Run your meds through the checker above

The bottom line

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

If you're looking to support cholesterol and heart health, barley has solid evidence behind it. Skip this if you take triclabendazole, or talk with your pharmacist about timing.

Not suitable if you have celiac disease or gluten sensitivity. Pregnant or breastfeeding?

There isn't enough safety data on the concentrated supplement form — talk with your doctor or pharmacist first.

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

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 26, 2014.

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 Barley Grass 500 mg, straight from the product label.

Brand Thompson
Barcode (UPC) 031315191701
Net contents 100 Tablet(s)
Market status On market
Date entered into DSLD Aug 26, 2014
DSLD ID 36463
Product type Botanical
Supplement form Tablet Or Pill
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Organic
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 Barley Grass 500 mg by Thompson, 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 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
UPC/BARCODE
031315191701
IngredientAmount% DV
Calories2 {Calories}--
Total Carbohydrates0.5 Gram(s)1%
Protein0.087 Gram(s)1%
Dietary Fiber0.5 Gram(s)2%
organic Barley500 mg--

Other ingredients: Cellulose, Magnesium Stearate, Silica

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.
Precautions

Caution: Barely grass is a powerful natural food. For some, it may cause slight detoxification symptoms. We suggest starting with a lower amount, then increasing gradually as desired.

WARNING: Do not use if safety seal is broken or missing.

Keep out of reach of children.

Do not use if pregnant or nursing.

Brand IP Statement(s)

Our own laboratory analysis guarantees purity and freshness of all Thompson(R) products.

(C)2012

Formulation

Certified organic by QAI

General Statements

Product of Canada

SINCE 1932

ORGANICALLY GROWN

FRESH HEALTHY

ONCE DAILY

Keep your licensed health car practitioner informed when using this product.

General

1121554 0112

Suggested/Recommended/Usage/Directions

Directions: Use only as directed. Take one tablet up to seven times daily with a meal or glass of water.

Storage

Store in a cool, dry place.

FDA Statement of Identity

DIETARY SUPPLEMENT

See for yourself

Barley Grass 500 mg by Thompson label

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

What’s inside

The Ingredients in Barley Grass 500 mg by Thompson

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Tablet(s) Dosage formTablet Or Pill Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Protein

0.087 Gram(s) per serving

Dietary Fiber

Interacts with
2,025 drugs
0.5 Gram(s) per serving

Black psyllium is a soluble-fiber supplement made from the seeds of a Plantago plant, used mostly to ease constipation and support digestive health. I...

Dietary Fiber monograph & interactions

Organic Barley

Interacts with
1 drug
500 mg per serving

Barley is a nutritious whole grain that is a good source of soluble fiber called beta-glucan, which has solid evidence for modestly lowering LDL ('bad...

Organic Barley monograph & interactions

Other (inactive) ingredients: Cellulose, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Barley Grass 500 mg by Thompson Drug Interactions

Want to check YOUR meds against Barley Grass 500 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
2,025Drugs
24 Moderate 2,001 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in Barley Grass 500 mg with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Dietary Fiber7 drug types · 2,025 drugs

Carbamazepine (Tegretol)

Theoretically, black psyllium might reduce the effects of carbamazepine and increase the risk for convulsions.
Theoretically, black psyllium might reduce carbamazepine absorption. A preliminary study using blond psyllium reported decreased carbamazepine bioavailability due to binding of the drug to psyllium, as well as reduction of available fluid in the gut for dissolution of the drug. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Lithium

Theoretically, taking black psyllium at the same time as lithium might reduce lithium absorption.
The fiber in black psyllium might reduce lithium absorption and plasma levels. Some case reports describe a reduction in plasma lithium levels with concomitant administration of blond psyllium. This was reversed when psyllium was stopped. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Metformin (Glucophage)

Theoretically, black psyllium might increase the therapeutic and adverse effects of metformin.
Animal research shows that concurrent consumption of blond psyllium with metformin slows and increases the absorption of metformin. This interaction may also occur with black psyllium. To avoid changes in absorption, take psyllium 30-60 minutes after metformin.

Likelihood Possible Evidence D
Olanzapine (Zyprexa)

Theoretically, taking black psyllium at the same time as olanzapine might reduce olanzapine absorption.
The fiber in black psyllium might decrease the absorption of olanzapine. A single case report describes a reduction in the effectiveness of olanzapine when it was concomitantly administered with an unspecified type of psyllium 3 grams orally twice daily. This effect was reversed when psyllium was stopped.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Theoretically, taking black psyllium at the same time as digoxin might reduce digoxin absorption and decrease digoxin levels.
Psyllium might bind digoxin in the gut. However, some clinical evidence suggests that psyllium does not impact digoxin absorption.

Likelihood Unlikely Evidence B
Ethinyl Estradiol

Theoretically, taking black psyllium at the same time as ethinyl estradiol might alter levels of estradiol.
Concurrent use of blond psyllium with ethinyl estradiol results in a slight increase in the extent of ethinyl estradiol absorption and a slower rate of absorption. This is unlikely to be clinically significant.

Likelihood Unlikely Evidence D
Oral Drugs

Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.
Psyllium seems to have variable effects on drug absorption. To avoid changes in absorption, take psyllium 30-60 minutes after oral medications. Animal research shows that blond psyllium delays and increases the absorption of metformin and ethinyl estradiol. Case reports and animal research suggest that blond psyllium might reduce absorption of lithium, digoxin, olanzapine, and carbamazepine. Finally, some pharmacokinetic studies show that psyllium does not affect the absorption of levothyroxine or warfarin. Although many of these studies evaluated blond psyllium, the fiber content in black psyllium may have similar effects.

Likelihood Possible Evidence B

organic Barley1 drug type · 1 drug

Triclabendazole (Egaten)

Theoretically, barley might decrease the clinical effects of triclabendazole.
Animal research suggests that a diet supplemented with barley can reduce the bioavailability of triclabendazole when taken concomitantly. This effect has not been shown in humans.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Barley Grass 500 mg, from the product label.

Thompson

See all Thompson products
Name
NutraPure, Inc.
Web Address
www.reachforlife.com
Pharmacist Counseling Corner

Barley Grass 500 mg by Thompson: Common Questions

Does Barley Grass 500 mg by Thompson interact with any medications?
Yes. Based on its ingredients, Barley Grass 500 mg has a known interaction with 2,025 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Barley Grass 500 mg contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
Does barley grass have gluten in it?
Yes. Barley naturally contains gluten, so this product isn't suitable if you have celiac disease or gluten sensitivity.
Is it safe to take while pregnant?
Barley as a food is fine during pregnancy, but there isn't enough safety data on concentrated barley supplements. Talk with your doctor or pharmacist about whether this particular product is right for you.
Is it safe while breastfeeding?
There's little safety data on concentrated barley supplements during breastfeeding. Check with your doctor or pharmacist before starting.
What side effects might I experience?
Most common are mild: bloating, gas, abdominal distension, and unpleasant taste. Allergic reactions are rare but possible — if you have a history of grain allergies, mention it to your pharmacist first.
What does this supplement actually do?
Barley is likely effective for lowering cholesterol and supporting heart health. The evidence supports these two uses; we don't have established effectiveness for other conditions.

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

Not sure if Barley Grass 500 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.

Barley Grass 500 mg label
Sources

Sources & How We Checked

Barley Grass 500 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 33 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.

Black Psyllium 18 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  4. Etman M. Effect of a bulk forming laxative on the bioavailablility of carbamazepine in man. Drug Dev Ind Pharm 1995;21:1901-6.
  5. Perlman BB. Interaction between lithium salts and ispaghula husk. Lancet 1990;335:416.
  6. Vaswani SK, Hamilton RG, Valentine MD, Adkinson NF. Psyllium laxative-induced anaphylaxis, asthma, and rhinitis. Allergy 1996;51:266-8. PubMed
  7. Lantner RR, Espiritu BR, Zumerchik P, Tobin MC. Anaphylaxis following ingestion of a psyllium-containing cereal. JAMA 1990;264:2534-6. DOI
  8. Kaplan MJ. Anaphylactic reaction to "Heartwise." N Engl J Med 1990;323:1072-3. DOI
  9. Nordstrom M, Melander A, Robertsson E, Steen B. Influence of wheat bran and of a bulk-forming ispaghula cathartic on the bioavailability of digoxin in geriatric in-patients. Drug Nutr Interact 1987;5:67-9..
  10. Robinson DS, Benjamin DM, McCormack JJ. Interaction of warfarin and nonsystemic gastrointestinal drugs. Clin Pharmacol Ther 1971;12:491-5. PubMed
  11. Garcia JJ, Fernandez N, Diez MJ, et al. Influence of two dietary fibers in the oral bioavailability and other pharmacokinetic parameters of ethinyloestradiol. Contraception 2000;62:253-7. PubMed
  12. Fernandez N, Lopez C, Díez R, et al. Drug interactions with the dietary fiber Plantago ovata husk. Expert Opin Drug Metab Toxicol 2012;8(11):1377-86.
  13. Semen plantaginis in: WHO Monographs on Selected Medicinal Plants, volume 1. World Health Organization, Geneva, 1999. Available at http://apps.who.int/medicinedocs/en/d/Js2200e/. Accessed November 26, 1026.
  14. Code of Federal Regulations, Title 21 (21CFR 101.17). Food labeling warning, notice, and safe handling statements. Available at www.ecfr.gov/cgi-bin/text-idx?SID=20f647d3b74161501f46564b915b4048&mc=true&node=se21.2.101_117&rgn=div8. Accessed December 3, 2
  15. Code of Federal Regulations, Title 21 (21CFR 201.319). Specific labeling requirements - water-soluble gums, hydrophilic gums, and hydrophilic mucilloids. Available at www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=201.319. Accessed Dece
  16. Diez R, Garcia JJ, Diez MJ, Sierra M, Sahagun AM, Fernandez N. Influence of Plantago ovata husk (dietary fiber) on the bioavailability and other pharmacokinetic parameters of metformin in diabetic rabbits. BMC Complement Altern Med. 2017 Jun 7;17(1):298. PubMed
  17. Chiu AC, Sherman SI. Effects of pharmacological fiber supplements on levothyroxine absorption. Thyroid. 1998;8(8):667-71. PubMed
  18. Merrick C, Madden CA, Capurso NA. A Case of Blunted Orally Disintegrating Olanzapine Effect Due to Coadministered Psyllium. J Clin Psychiatry 2021;82(2):20cr13633. PubMed

See these in context on the Black Psyllium monograph →

Barley 15 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Fernandez-Anaya S, Crespo JF, Rodriguez JR, et al. Beer anaphylaxis. J Allergy Clin Immunol 1999;103:959-60.
  3. Lembo A, Camilleri M. Chronic constipation. N Engl J Med 2003;349:1360-8. . PubMed
  4. Ferre, I., Giraldez, F. J., Alvarez-Bujidos, M. L., and Mantecon, A. R. Influence of barley supplement on plasma concentration of triclabendazole metabolites in sheep. Vet.Rec. 11-22-1997;141(21):549-551. PubMed
  5. Curioni, A., Santucci, B., Cristaudo, A., Canistraci, C., Pietravalle, M., Simonato, B., and Giannattasio, M. Urticaria from beer: an immediate hypersensitivity reaction due to a 10- kDa protein derived from barley. Clin Exp Allergy 1999;29(3):407-413. PubMed
  6. Fernandez-Anaya, S., Crespo, J. F., Rodriguez, J. R., Daroca, P., Carmona, E., Herraez, L., and Lopez-Rubio, A. Beer anaphylaxis. J Allergy Clin Immunol. 1999;103(5 Pt 1):959-960.
  7. Cronin, E. Contact dermatitis from barley dust. Contact Dermatitis 1979;5(3):196. PubMed
  8. Block, G., Tse, K. S., Kijek, K., Chan, H., and Chan-Yeung, M. Baker's asthma. Studies of the cross-antigenicity between different cereal grains. Clin Allergy 1984;14(2):177-185.
  9. van Ketel, W. G. Immediate type allergy to malt in beer. Contact Dermatitis 1980;6(4):297-298. PubMed
  10. Ellis, H. J., Doyle, A. P., Day, P., Wieser, H., and Ciclitira, P. J. Demonstration of the presence of coeliac-activating gliadin-like epitopes in malted barley. Int Arch Allergy Immunol. 1994;104(3):308-310. PubMed
  11. Vidal, C. and Gonzalez-Quintela, A. Food-induced and occupational asthma due to barley flour. Ann Allergy Asthma Immunol. 1995;75(2):121-124.
  12. Gutgesell, C. and Fuchs, T. Contact urticaria from beer. Contact Dermatitis 1995;33(6):436-437. PubMed
  13. Baker, P. G. and Read, A. E. Oats and barley toxicity in coeliac patients. Postgrad.Med J 1976;52(607):264-268. PubMed
  14. Nakase, M., Usui, Y., Alvarez-Nakase, A. M., Adachi, T., Urisu, A., Nakamura, R., Aoki, N., Kitajima, K., and Matsuda, T. Cereal allergens: rice-seed allergens with structural similarity to wheat and barley allergens. Allergy 1998;53(46 Suppl):55-57. PubMed
  15. Pereira, F., Rafael, M., and Lacerda, M. H. Contact dermatitis from barley. Contact Dermatitis 1998;39(5):261-262. PubMed

See these in context on the Barley 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

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