Drug & supplement interaction

Inulin + Promethazine

Promethazine brand name: Phenergan.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Inulin 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.

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Interaction report

Inulin 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 Inulin 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.

Inulin safety at a glance

Inulin overall Use caution Generally well tolerated in food amounts but often causes gas and bloating, especially at higher doses.
Pregnancy Likely Safe When used orally in amounts commonly found in foods. There is insufficient reliable information available about using inulin in medicinal amounts during pregnan... Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in foods. There is insufficient reliable information available about using inulin in medicinal amounts during pregnan... 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 Promethazine and Inulin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

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. Inulin has documented interactions with 1 drug class — the most serious being antidiabetes drugs (minor) — 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.

Keep it in perspective

Inulin Does Interact With Other Medications

Inulin has 86 minor known drug interactions in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Inulin

Covers the 2,830 medications we’ve checked against Inulin. Pick one to open its full report.

What to actually watch for

What Inulin Itself Has Been Linked To

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

  • A severe allergic reaction Worth acting on Additional detail

    “Orally, inulin is well tolerated.

    Most Common Adverse Effects:

    Orally: Bloating, constipation, diarrhea, flatulence, and gastrointestinal cramps.

    Serious Adverse Effects (Rare):

    Orally: Anaphylaxis has occurred following consumption of foods high in inulin.”

    Inulin · Natural Medicines adverse-effect record, reported in constipation.

  • Bloating or gas / Constipation / Diarrhea Additional detail

    “Orally, inulin may cause flatulence, bloating, diarrhea, constipation, and gastrointestinal cramps, especially at doses over 30 grams.”

    Inulin · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 7604. Williams CM. Effects of inulin on lipid parameters in humans. J Nutr 1999 Jul;129(7 Suppl):1471S-3S. PubMed
    2. 8450. Pedersen A, Sandstrom B, Van Amelsvoort JM. The effect of ingestion of inulin on blood lipids and gastrointestinal symptoms in healthy females. Br J Nutr 1997;78:215-22. PubMed
    3. 8509. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
    4. 93716. Bonnema AL, Kolberg LW, Thomas W, Slavin JL. Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc 2010;110(6):865-8. PubMed
    5. 93721. Guess ND, Dornhorst A, Oliver N, Frost GS. A randomised crossover trial: the effect of inulin on glucose homeostasis in subtypes of prediabetes. Ann Nutr Metab 2016;68(1):26-34. PubMed
    6. 93724. Marteau P, Jacobs H, Cazaubiel M, Signoret C, Prevel JM, Housez B. Effects of chicory inulin in constipated elderly people: a double-blind controlled trial. Int J Food Sci Nutr 2011;62(2):164-70. PubMed

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

Special populations

Inulin in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in amounts commonly found in foods. There is insufficient reliable information available about using inulin in medicinal amounts during pregnancy or lactation; avoid use.

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

From our Q&A

Questions About Inulin 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 Inulin 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:

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 Promethazine

This page covers Inulin 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

Open the Promethazine interaction page

One more smart check

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

We hold 1,362 real supplement products containing Inulin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Inulin. Even though Inulin 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:

How much people look this up

Where Inulin 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.

Supplement Inulin
Top 25%

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

29 days ago today
Medication Promethazine
Steady interest

#2,040 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 Inulin reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Inulin and Promethazine 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 Inulin

What is Inulin?

  • Constipation and regularity
  • Prebiotic gut health
  • Blood sugar support
  • Calcium absorption
  • Weight management
  • Cholesterol support

Inulin is a type of plant fiber (a prebiotic) found naturally in foods like chicory root, onions, and garlic, and it is widely added to supplements and processed foods. It may help with regularity and feeding healthy gut bacteria, but it commonly causes gas and bloating, especially at higher doses. Start low, increase slowly, and check with your pharmacist or doctor if you have gut conditions.

Roots and other storage tissues of plants (often chicory root) · Powder, capsules, chewable tablets, gummies, and added to foods and drinks

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

Inulin: dosing

There is no single official dose of inulin. The right amount varies by person and by why you are taking it. Many supplement products provide a few grams of fiber per serving.A practical approach is to start low and go slow — begin with a small amount and gradually increase over days or weeks to reduce gas and bloating.

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

Read the full Inulin monograph & all interactions
Medication

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.

Dependence 3,586 reports
Nausea 2,646 reports
Vomiting 1,802 reports
Fatigue 1,496 reports
Diarrhea 1,341 reports
See full Promethazine drug information
Keep checking

Other Drugs & Inulin

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

0Major
0Moderate
86Minor
2,743No known interaction
Minor

86 interactions

Showing 60 of 86 minor interactions — see all 86 on the Inulin page.

No interaction 2,743 drugs checked — show the list
Evidence & sources

Inulin References

The 17 references that drive our Inulin 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. Williams CM. Effects of inulin on lipid parameters in humans. J Nutr 1999 Jul;129(7 Suppl):1471S-3S. PubMed
  2. Pedersen A, Sandstrom B, Van Amelsvoort JM. The effect of ingestion of inulin on blood lipids and gastrointestinal symptoms in healthy females. Br J Nutr 1997;78:215-22. PubMed
  3. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
  4. Bonnema AL, Kolberg LW, Thomas W, Slavin JL. Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc 2010;110(6):865-8. PubMed
  5. Dehghan P, Gargari BP, Jafar-Abadi MA, Aliasgharzadeh A. Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: a randomized-controlled clinical trial. Int J Food Sci Nutr 2014;65(1):117-23. PubMed
  6. Guess ND, Dornhorst A, Oliver N, Frost GS. A randomised crossover trial: the effect of inulin on glucose homeostasis in subtypes of prediabetes. Ann Nutr Metab 2016;68(1):26-34. PubMed
  7. Marteau P, Jacobs H, Cazaubiel M, Signoret C, Prevel JM, Housez B. Effects of chicory inulin in constipated elderly people: a double-blind controlled trial. Int J Food Sci Nutr 2011;62(2):164-70. PubMed
  8. Mensink MA, Frijlink HW, van der Voort Maarschalk K, Hinrichs WL. Inulin, a flexible oligosaccharide I: review of its physicochemical characteristics. Carbohydr Polym 2015;130:405-19. PubMed
  9. Slavin J, Feirtag J. Chicory inulin does not increase stool weight or speed up intestinal transit time in healthy male subjects. Food Funct. 2011;2(1):72-7. PubMed
  10. Micka A, Siepelmeyer A, Holz A, Theis S, Schön C. Effect of consumption of chicory inulin on bowel function in healthy subjects with constipation: a randomized, double-blind, placebo-controlled trial. Int J Food Sci Nutr. 2017;68(1):82-89. PubMed
  11. Smiljanec K, Mitchell CM, Privitera OF, Neilson AP, Davy KP, Davy BM. Pre-meal inulin consumption does not affect acute energy intake in overweight and obese middle-aged and older adults: A randomized controlled crossover pilot trial. Nutr Health. 2017;23 PubMed
  12. Cai X, Yu H, Liu L, et al. Milk powder co-supplemented with inulin and resistant dextrin improves glycemic control and insulin resistance in elderly type 2 diabetes mellitus: a 12-week randomized, double-blind, placebo-controlled trial. Mol Nutr Food Res PubMed
  13. Rao M, Gao C, Xu L, et al. Effect of inulin-type carbohydrates on insulin resistance in patients with type 2 diabetes and obesity: a systematic review and meta-analysis. J Diabetes Res. 2019;2019:5101423. PubMed
  14. Mitchell CM, Davy BM, Ponder MA, et al. Prebiotic Inulin Supplementation and Peripheral Insulin Sensitivity in adults at Elevated Risk for Type 2 Diabetes: A Pilot Randomized Controlled Trial. Nutrients 2021;13(9):3235. PubMed
  15. Li L, Li P, Xu L. Assessing the effects of inulin-type fructan intake on body weight, blood glucose, and lipid profile: A systematic review and meta-analysis of randomized controlled trials. Food Sci Nutr 2021;9(8):4598-4616. 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 Inulin and Promethazine Together: Common Questions

Is it safe to take Inulin with Promethazine?
We do not list a known interaction between Inulin and Promethazine. 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.
How was the Inulin and Promethazine combination checked?
Interactions in our licensed database are recorded against drug classes. Promethazine is filed under 4 classifications, and Inulin has documented interactions with 1 drug class — none of Promethazine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Inulin interact with any other medications?
Yes. Inulin has 86 documented drug interactions in our database — Promethazine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Promethazine interact with any supplements?
Yes. Promethazine has documented interactions with 83 supplements in our database — Inulin is not one of them. The Promethazine interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Promethazine and Inulin?

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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.