Barley + Promethazine
Promethazine brand name: Phenergan.
We found no known interaction between Barley and Promethazine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.
Barley and Promethazine
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Promethazine and Barley in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
Barley safety at a glance
Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Why No Interaction Is Listed for Promethazine
Interactions in our licensed database are recorded against drug classes, not just single drug names. Promethazine is filed under 4 classifications — including phenothiazines, anticholinergic drugs, photosensitizing drugs. Barley has documented interactions with 1 drug class — the most serious being triclabendazole (egaten) (moderate) — and none of Promethazine’s classifications are among them.
Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.
Barley Does Interact With Other Medications
Barley has 1 moderate known drug interaction in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Barley
We haven’t checked that one against Barley yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Barley. Pick one to open its full report.
Barley in Pregnancy & Breastfeeding
When used orally in amounts commonly found in foods.
When barley sprouts are consumed in relatively high doses. Excessive amounts of barley sprouts should not be consumed during pregnancy.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center
Questions About Barley or Promethazine
These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Barley or Promethazine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:
- Can Trazodone Cause A False-Positive For Amphetamines? ›
- Can You Take Benadryl With A Z-Pak (Azithromycin)? ›
- Taking Promethazine With Codeine With NyQuil ›
Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Promethazine
This page covers Barley only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).
By severity: 3 major · 57 moderate · 23 minor.
From our pharmacist’s overview on the Promethazine page
“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”
Reviewed by 2 · Jul 18, 2026
Taking Barley as Part of a Dietary Supplement Product? Check It for Interactions
We hold 2,448 real supplement products containing Barley, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Barley. Even though Barley itself has no known interaction with Promethazine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Barley and Promethazine Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#163 of 1,452 supplements looked up here in the last 7 days
#1,415 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Barley reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Barley and Promethazine records this page draws on were last updated July 11, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About Barley
What is Barley?
- High cholesterol
- Heart health support
- Blood sugar support
- Digestive regularity and fiber
- General nutrition
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') cholesterol when eaten regularly. It is safe as a food for most people, but those with celiac disease or gluten sensitivity should avoid it since it contains gluten. Talk to your pharmacist or doctor before using concentrated barley supplements, especially if you have a health condition.
Hordeum vulgare · Poaceae · Grain (seed), and sometimes young leaves/grass and bran · Whole grain, flour, flakes, barley bran, beta-glucan supplements, barley grass powder, tea, and capsules
An interaction check asks whether these two react with each other — it does not ask whether Barley is a good idea for someone in your situation. Here is what our Barley record says about it on its own.
Barley: dosing
There is no single official supplement dose for barley. For cholesterol benefits, research has generally used a few grams of barley beta-glucan per day, taken as part of the diet, but the exact amount can vary by product.Because products differ widely in strength and form, the best approach is to follow the directions on the product label.
From our Barley monograph — the full record covers uses, side effects and every documented interaction.
About Promethazine
What Is Promethazine Used For?
Brand name: Phenergan
Promethazine is used for a wide range of conditions. Tablets, oral solution, and rectal suppositories (brands including Phenergan, Promethegan, and Phenadoz) are approved for seasonal and perennial allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, hives (urticaria), angioedema, dermographism, and allergic reactions to blood or plasma. They are also used for motion sickness (both prevention and active treatment), nausea and vomiting related to anesthesia and surgery, sedation, and as a helper medication alongside pain relievers after surgery.
Promethazine hydrochloride injection (brands including Phenergan and Promethazine HCl injection) is used for many of the same purposes but is reserved for situations where oral treatment is not possible — including allergic emergencies as an adjunct to epinephrine, sedation during labor, and as an aid during certain surgical procedures such as bronchoscopy and eye surgery.
Most-Reported Side Effects for Promethazine
From FAERS, the FDA’s public side-effect reporting system (22,614 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Barley
Browse every other medication we’ve checked against Barley — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
No interaction 2,828 drugs checked — show the list
We also checked Barley against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Losartan Potassium ›
- Testosterone ›
- Ivermectin ›
- Aspirin ›
- Abemaciclib ›
- Acetaminophen ›
- Metoprolol ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Tadalafil ›
- Tirzepatide ›
- Methamphetamine ›
- Ibuprofen ›
- Warfarin Sodium ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Lisdexamfetamine ›
- Propranolol ›
- Metformin ›
- Amitriptyline ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Amlodipine Besylate ›
- Methotrexate ›
- Bendamustine ›
- Bupropion ›
- Amphetamine ›
- Doxycycline ›
- Fluoxetine ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Levothyroxine, Liothyronine ›
- Clonazepam ›
- Quetiapine ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Methylene Blue ›
- Duloxetine ›
- Buspirone ›
- Citalopram ›
Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Barley list.
Barley References
The 15 references that drive our Barley monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
- Fernandez-Anaya S, Crespo JF, Rodriguez JR, et al. Beer anaphylaxis. J Allergy Clin Immunol 1999;103:959-60.
- Lembo A, Camilleri M. Chronic constipation. N Engl J Med 2003;349:1360-8. . PubMed
- 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
- 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
- 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.
- Cronin, E. Contact dermatitis from barley dust. Contact Dermatitis 1979;5(3):196. PubMed
- 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.
- van Ketel, W. G. Immediate type allergy to malt in beer. Contact Dermatitis 1980;6(4):297-298. PubMed
- 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
- Vidal, C. and Gonzalez-Quintela, A. Food-induced and occupational asthma due to barley flour. Ann Allergy Asthma Immunol. 1995;75(2):121-124.
- Gutgesell, C. and Fuchs, T. Contact urticaria from beer. Contact Dermatitis 1995;33(6):436-437. PubMed
- Baker, P. G. and Read, A. E. Oats and barley toxicity in coeliac patients. Postgrad.Med J 1976;52(607):264-268. PubMed
- 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
- Pereira, F., Rafael, M., and Lacerda, M. H. Contact dermatitis from barley. Contact Dermatitis 1998;39(5):261-262. PubMed
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Taking Barley and Promethazine Together: Common Questions
Is it safe to take Barley with Promethazine?
Do Barley and Promethazine have any of the same side effects?
How was the Barley and Promethazine combination checked?
Does Barley interact with any other medications?
Does Promethazine interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Keep Exploring
Still Have a Question About Promethazine and Barley?
Our pharmacists answer your medication & supplement questions — free.
This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.