Drug & supplement interaction

Wheat Bran + Phenylephrine

Phenylephrine brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Wheat Bran and Phenylephrine 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.

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Interaction report

Wheat Bran and Phenylephrine

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 Phenylephrine and Wheat Bran 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Wheat Bran at all — not against Phenylephrine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Wheat Bran safety at a glance

Wheat Bran overall Use caution Generally safe as a food for most people, but it contains gluten and should be increased slowly with plenty of fluids.
Pregnancy Likely Safe When used orally. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally. Read the full breastfeeding detail

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.

Still wondering about combining Phenylephrine and Wheat Bran? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Wheat Bran Itself Has Been Linked To

This is not an interaction — nothing below involves Phenylephrine. It is the side-effect record for Wheat Bran on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Wheat Bran, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • A severe allergic reaction Worth acting on Additional detail

    “Orally, wheat bran seems to be well tolerated.

    Most Common Adverse Effects:

    Orally: Flatulence and gastrointestinal discomfort.

    Serious Adverse Effects (Rare):

    All routes of administration: Wheat products can cause allergic reactions, including anaphylaxis.”

    Wheat Bran · Natural Medicines adverse-effect record, reported in flatulence.

  • An allergic reaction Worth acting on Additional detail

    “Wheat can cause allergic reactions in sensitive individuals. Due to the prevalence of this allergy in the general population, wheat and wheat products, such as wheat bran, are classified as major food allergens in the United States.”

    Wheat Bran · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    1 source cited
    1. 105410. Food and Drug Administration. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA); Public Law 108-282, Title II. Accessed on May 19, 2021. Available at: https://www.fda.gov/food/food-allergensgluten-free-guidance-documents-regulatory-infor
  • Bloating or gas / Stomach upset Additional detail

    “Orally, wheat bran may cause flatulence and gastrointestinal discomfort, especially with initial use. However, 2 clinical studies designed to look at side effects noted no increase in GI symptoms in subjects taking 20 to 40 grams of wheat bran per day.”

    Wheat Bran · Natural Medicines adverse-effect record, reported in flatulence.

    2 sources cited
    1. 6265. McRorie J, Kesler J, Bishop L, et al. Effects of wheat bran and Olestra on objective measures of stool and subjective reports of GI symptoms. Am J Gastroenterol 2000;95:1244-52. PubMed
    2. 113128. Dalile B, La Torre D, Kalc P, et al. Extruded Wheat Bran Consumption Increases Serum Short-Chain Fatty Acids but Does Not Modulate Psychobiological Functions in Healthy Men: A Randomized, Placebo-Controlled Trial. Front Nutr 2022;9:896154. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Wheat Bran — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Phenylephrine’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Phenylephrine column appears here.

Special populations

Wheat Bran in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally.

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

Overlapping uses

What Phenylephrine Is Prescribed For, and What Wheat Bran Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Phenylephrine is a prescription medicine with approved uses on its FDA label. Wheat Bran is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Phenylephrine is prescribed for: Phenylephrine is used in several different products, and each one has its own use. Injection (IV): raises blood pressure in adults with clinically important hypotension (low blood pressure) caused mainly by widened blood vessels. Some injections are labeled for anesthesia only. Others are labeled for anesthesia and septic shock.

Read the rest of what Phenylephrine is prescribed for

Eye drops: Phenylephrine Hydrochloride Ophthalmic Solution is used to dilate the pupil. Nasal products: temporarily relieve nasal and sinus congestion from the common cold, hay fever or other upper respiratory allergies. Rectal suppositories: relieve itching, burning and discomfort from hemorrhoids and temporarily shrink hemorrhoidal tissue.

Wheat Bran has been studied for:

  • Hemorrhoids Natural Medicines rates the evidence for Wheat Bran: Possibly Effective Read what the research shows

    Wheat Bran for hemorrhoids

    Oral wheat bran may reduce the risk for hemorrhoids in some people.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Phenylephrine on your own; if you are taking Wheat Bran for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Wheat Bran or Phenylephrine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Wheat Bran or Phenylephrine, 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:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Phenylephrine

This page covers Wheat Bran only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenylephrine page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Lithium (major), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 60 moderate · 15 minor.

From our pharmacist’s overview on the Phenylephrine page

“If you take phenylephrine (Sudafed PE, Biorphen) for congestion, treat this list as one that needs real attention, since six of its 81 entries carry a major rating. Phenylephrine tightens blood vessels to clear your nose, and more than half of the interactions here come from stimulant ingredients, ephedra above all, that can push blood…”

Reviewed by 2 · Jul 18, 2026

Open the Phenylephrine interaction page

One more smart check

Taking Wheat Bran as Part of a Dietary Supplement Product? Check It for Interactions

We hold 8 real supplement products containing Wheat Bran, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wheat Bran. Even though Wheat Bran itself has no known interaction with Phenylephrine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Wheat Bran and Phenylephrine 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.

Supplement Wheat Bran
Steady interest

#899 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenylephrine
Top 25%

#444 of 2,830 medications looked up here in the last 7 days

29 days ago today

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 Wheat Bran reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Wheat Bran and Phenylephrine records this page draws on were last updated July 10, 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.
Data structure & sourcing designed and verified by .
Supplement

About Wheat Bran

What is Wheat Bran?

  • Constipation relief
  • Digestive regularity
  • Heart health support
  • Blood sugar support
  • Weight management

Wheat bran is the fiber-rich outer layer of the wheat kernel and is best known as a natural bulk-forming way to relieve constipation and support regular bowel movements. It is generally safe for most people who can eat wheat, but it must be taken with plenty of water and should be avoided by anyone with a wheat allergy, celiac disease, or gluten sensitivity.

Triticum aestivum · Poaceae · Outer bran layer of the wheat grain · Loose bran, breakfast cereals, baked goods, capsules, and powders

An interaction check asks whether these two react with each other — it does not ask whether Wheat Bran is a good idea for someone in your situation. Here is what our Wheat Bran record says about it on its own.

Wheat Bran: dosing

There is no single official dose of wheat bran as a supplement. Most people use it simply as a food, adjusting the amount to keep their bowels regular.A good general rule is to start with a small amount and increase slowly over days to weeks, while drinking plenty of water.

From our Wheat Bran monograph — the full record covers uses, side effects and every documented interaction.

Read the full Wheat Bran monograph & all interactions
Medication

About Phenylephrine

What Is Phenylephrine Used For?

Brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen

Phenylephrine is used in several different products, and each one has its own use.

Injection (IV): raises blood pressure in adults with clinically important hypotension (low blood pressure) caused mainly by widened blood vessels. Some injections are labeled for anesthesia only. Others are labeled for anesthesia and septic shock.

Eye drops: Phenylephrine Hydrochloride Ophthalmic Solution is used to dilate the pupil.

Nasal products: temporarily relieve nasal and sinus congestion from the common cold, hay fever or other upper respiratory allergies.

Rectal suppositories: relieve itching, burning and discomfort from hemorrhoids and temporarily shrink hemorrhoidal tissue.

Most-Reported Side Effects for Phenylephrine

From FAERS, the FDA’s public side-effect reporting system (221,388 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 20,609 reports
Headache 17,301 reports
Nausea 16,925 reports
Diarrhea 14,221 reports
Dyspnea 13,719 reports
See full Phenylephrine drug information
Keep checking

Other Drugs & Wheat Bran

Browse every other medication we’ve checked against Wheat Bran — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Wheat Bran against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Wheat Bran list.

See the full Wheat Bran interactions page
See every supplement checked against Phenylephrine, ranked by severity
Evidence & sources

Wheat Bran References

The 4 references that drive our Wheat Bran 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.

  1. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. McRorie J, Kesler J, Bishop L, et al. Effects of wheat bran and Olestra on objective measures of stool and subjective reports of GI symptoms. Am J Gastroenterol 2000;95:1244-52. PubMed
  3. Food and Drug Administration. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA); Public Law 108-282, Title II. Accessed on May 19, 2021. Available at: https://www.fda.gov/food/food-allergensgluten-free-guidance-documents-regulatory-infor
  4. Dalile B, La Torre D, Kalc P, et al. Extruded Wheat Bran Consumption Increases Serum Short-Chain Fatty Acids but Does Not Modulate Psychobiological Functions in Healthy Men: A Randomized, Placebo-Controlled Trial. Front Nutr 2022;9:896154. 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.

Pharmacist Counseling Corner

Taking Wheat Bran and Phenylephrine Together: Common Questions

Is it safe to take Wheat Bran with Phenylephrine?
We do not list a known interaction between Wheat Bran and Phenylephrine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Are Wheat Bran and Phenylephrine used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Wheat Bran in each. That is a conversation for your prescriber, especially if Phenylephrine is being adjusted to a target.
Does Phenylephrine interact with any supplements?
Yes. Phenylephrine has documented interactions with 81 supplements in our database — Wheat Bran is not one of them. The Phenylephrine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Wheat Bran monograph Uses, safety profile, and every drug interaction in one place Phenylephrine drug information The full plain-English guide to this medication Phenylephrine supplement interactions Every supplement checked against Phenylephrine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Phenylephrine and Wheat Bran?

Our pharmacists answer your medication & supplement questions — free.

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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.