Drug & supplement interaction

Bromelain + Metformin

Metformin brand names: Glucophage, Metformin.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Bromelain and Metformin 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.

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Interaction report

Bromelain and Metformin

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 Metformin and Bromelain 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.

Bromelain safety at a glance

Bromelain overall Use caution Generally well tolerated short-term, but evidence on long-term use is limited.
Pregnancy Avoid Not enough safety data, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid it.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Metformin and Bromelain? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Metformin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Metformin is filed under 5 classifications — including organic cation transporter 2 (oct2) substrates, antidiabetes drugs, oral drugs. Bromelain has documented interactions with 2 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate) and tetracycline antibiotics (minor) — and none of Metformin’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

Bromelain Does Interact With Other Medications

Bromelain has 122 moderate, 19 minor known drug interactions in our database — Metformin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 Minor 19 No known interaction 2,689 (incl. Metformin)
Taking anything else?

Check Another of Your Medications Against Bromelain

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

What to actually watch for

No Interaction Found — But Data Suggests Bromelain and Metformin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Bloating or gas / Diarrhea Additional detail

    Bromelain

    “Orally, bromelain may cause gastrointestinal disturbances, including diarrhea, nausea, vomiting, flatulence, and abdominal pain.”

    Bromelain · Natural Medicines adverse-effect record, reported in diarrhea.

    5 sources cited
    1. 9184. Nettis E, Napoli G, Ferrannini A, Tursi A. IgE-mediated allergy to bromelain. Allergy 2001;56:257-8. PubMed
    2. 18274. Brien S, Lewith G, Walker AF, et al. Bromelain as an adjunctive treatment for moderate-to-severe osteoarthritis of the knee: a randomized placebo-controlled pilot study. QJM 2006;99:841-50. PubMed
    3. 18282. Mori S, Ojima Y, Hirose T, et al. The clinical effect of proteolytic enzyme containing bromelain and trypsin on urinary tract infection evaluated by double blind method. Acta Obstet Gynaecol Jpn 1972;19:147-53.
    4. 96216. Kasemsuk T, Saengpetch N, Sibmooh N, Unchern S. Improved WOMAC score following 16-week treatment with bromelain for knee osteoarthritis. Clin Rheumatol. 2016 Oct;35(10):2531-40. PubMed
    5. 113513. Leelakanok N, Petchsomrit A, Janurai T, Saechan C, Sunsandee N. Efficacy and safety of bromelain: A systematic review and meta-analysis. Nutr Health 2023. PubMed

    Metformin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin. Read the label on DailyMed ›

  • Stomach upset / Vomiting / Nausea Additional detail

    Bromelain

    Recorded for Bromelain in the same Natural Medicines adverse-effect record shown under Bloating or gas / Diarrhea above.

    Metformin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin. Read the label on DailyMed ›

  • A skin rash Additional detail

    Bromelain

    “Topically, bromelain may cause dermal allergic reactions including urticaria, pruritus, and skin swelling. Redness, swelling, burning, pain at the application site, and cellulitis have also been reported rarely. In one case, a fixed drug eruption with pruritis near the groin was reported in a 33-year-old male taking bromelain 50 mg orally daily for 10 days.”

    Bromelain · Natural Medicines adverse-effect record, reported in hypertension.

    5 sources cited
    1. 9184. Nettis E, Napoli G, Ferrannini A, Tursi A. IgE-mediated allergy to bromelain. Allergy 2001;56:257-8. PubMed
    2. 108148. Shoham Y, Shapira E, Haik J, et al. Bromelain-based enzymatic debridement of chronic wounds: Results of a multicentre randomized controlled trial. Wound Repair Regen 2021;29(6):899-907. PubMed
    3. 113513. Leelakanok N, Petchsomrit A, Janurai T, Saechan C, Sunsandee N. Efficacy and safety of bromelain: A systematic review and meta-analysis. Nutr Health 2023. PubMed
    4. 103300. Kutlu Ö, DemirbaS A, Elmas ÖF, Güvenç U, Metin A. Fixed drug eruption: a new side effect of bromelain. Contact Dermatitis 2020. Online ahead of print. PubMed
    5. 111656. Hasham S, Riyat H, Fletcher A, O'Boyle CP, Alexander S. To bleed or not to bleed? Case series and discussion of haemorrhage risk with enzymatic debridement in burn injuries. Scars Burn Heal 2023;9:20595131231168333. PubMed

    Metformin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin. Read the label on DailyMed ›

  • Headache Additional detail

    Bromelain

    Recorded for Bromelain in the same Natural Medicines adverse-effect record shown under Bloating or gas / Diarrhea above.

    Metformin

    Listed in the ADVERSE REACTIONS section of the FDA label for Metformin. Read the label on DailyMed ›

Reported for Bromelain but not commonly for Metformin: trouble swallowing, blood clots, an allergic reaction and stomach pain.

Effects for Metformin come from the ADVERSE REACTIONS section of its FDA label; effects for Bromelain come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Metformin Is Prescribed For, and What Bromelain Has Been Studied For

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

Metformin is prescribed for: Metformin is used to improve blood sugar (glucose) control in people with type 2 diabetes mellitus. It is always used together with diet and exercise, not instead of them. Metformin hydrochloride tablets and oral solution are approved for adults and children 10 years and older. Metformin hydrochloride extended-release tablets — including brands such as Fortamet, Glumetza, and Metformin Hydrochloride Extended Release — are approved for adults only.

Bromelain has been studied for:

  • Diabetes studied, not established Bromelain has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Bromelain for diabetes

    Oral bromelain has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

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 Metformin on your own; if you are taking Bromelain for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Bromelain or Metformin

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

This page covers Bromelain only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin page lists 258 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate) and Agaricus Mushroom (moderate).

By severity: 2 major · 217 moderate · 39 minor.

From our pharmacist’s overview on the Metformin page

“Siberian cocklebur is the ingredient I most want anyone taking metformin (Glucophage) to know about. It has caused severe low blood sugar in people, documented in humans, and it should not be combined with any glucose-lowering medication.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin interaction page

One more smart check

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

We hold 6,336 real supplement products containing Bromelain, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bromelain. Even though Bromelain itself has no known interaction with Metformin, 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 Bromelain and Metformin 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 Bromelain
Top 5%

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

29 days ago today
Medication Metformin
Top 1%

#29 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 Bromelain reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Bromelain and Metformin 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 Bromelain

What is Bromelain?

Bromelain
  • Inflammation and swelling
  • Sinus and nasal congestion
  • Digestion support
  • Post-surgery or injury recovery
  • Joint pain
  • Allergic rhinitis

Bromelain is a group of protein-digesting enzymes from pineapple that people take mainly for inflammation, swelling, and sinus problems. Some early studies are promising, but the overall evidence is limited and far from conclusive. It is generally well tolerated short-term, but pregnant and breastfeeding people should avoid it, and anyone with a pineapple allergy or bleeding concerns should check with a pharmacist first.

Ananas comosus · Bromeliaceae · Stem and fruit of the pineapple · Capsules, tablets, powder, topical preparations

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

Bromelain: dosing

There is no single standardized dose of bromelain that has been firmly established for any condition. Bromelain products are often measured in units of enzyme activity (such as GDU or MCU), which can vary widely between brands, making it hard to compare products.Because of this, the best approach is to follow the directions on the product label and not exceed the recommended amount. A pharmacist can help you understand the strength of a particular product and whether it is appropriate for you.

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

Read the full Bromelain monograph & all interactions
Medication

About Metformin

What Is Metformin Used For?

Brand names: Glucophage, Metformin

Metformin is used to improve blood sugar (glucose) control in people with type 2 diabetes mellitus. It is always used together with diet and exercise, not instead of them.

Metformin hydrochloride tablets and oral solution are approved for adults and children 10 years and older. Metformin hydrochloride extended-release tablets — including brands such as Fortamet, Glumetza, and Metformin Hydrochloride Extended Release — are approved for adults only.

See full Metformin drug information
Keep checking

Other Drugs & Bromelain

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

0Major
122Moderate
19Minor
2,688No known interaction
122 Moderate 19 Minor 2,688 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Bromelain page.

Minor

19 interactions

No interaction 2,688 drugs checked — show the list

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

Showing the 60 most looked-up of 2,688 medications checked with no known interaction — see the full Bromelain list.

See the full Bromelain interactions page
See every supplement checked against Metformin, ranked by severity
Evidence & sources

Bromelain References

The 19 references that drive our Bromelain 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. Nettis E, Napoli G, Ferrannini A, Tursi A. IgE-mediated allergy to bromelain. Allergy 2001;56:257-8. PubMed
  2. Taussig SJ, Batkin S. Bromelain, the enzyme complex of pineapple (Ananas comosus) and its clinical application. An update. J Ethnopharmacol 1988;22:191-203.. PubMed
  3. Bradbrook ID, Morrison PJ, Rogers HJ. The effect of bromelain on the absorption of orally administered tetracycline. Br J Clin Pharmacol 1978;6:552-4. PubMed
  4. Bush TM, Rayburn KS, Holloway SW, et al. Adverse interactions between herbal and dietary substances and prescription medications: a clinical survey. Altern Ther Health Med 2007;13:30-5.
  5. Brien S, Lewith G, Walker AF, et al. Bromelain as an adjunctive treatment for moderate-to-severe osteoarthritis of the knee: a randomized placebo-controlled pilot study. QJM 2006;99:841-50. PubMed
  6. Mori S, Ojima Y, Hirose T, et al. The clinical effect of proteolytic enzyme containing bromelain and trypsin on urinary tract infection evaluated by double blind method. Acta Obstet Gynaecol Jpn 1972;19:147-53.
  7. Glaser D, Hilberg T. The influence of bromelain on platelet count and platelet activity in vitro. Platelets 2006;17:37-41. PubMed
  8. Heinicke R M, van der Wal L, Yokoyama M. Effect of bromelain (Ananase) on human platelet aggregation. Experientia 1972;28:844-5. PubMed
  9. Gailhofer, G., Wilders-Truschnig, M., Smolle, J., and Ludvan, M. Asthma caused by bromelain: an occupational allergy. Clin Allergy 1988;18(5):445-450. PubMed
  10. Mattei, O., Fabri, G., and Farina, G. [Occupational health experience regarding four cases of asthma due to bromelain (author's transl)]. Medicina del Lavoro 1979;70(5):404-409.
  11. Galleguillos, F. and Rodriguez, J. C. Asthma caused by bromelin inhalation. Clin Allergy 1978;8(1):21-24. PubMed
  12. Perez-Camo I, Quirce S, Duran MA, and et al. Latex allergy: evidence of cross-reactivity with papain and bromelain [abstract]. Allergy 1996;51(suppl 31):48.
  13. Martin GJ, Ehrenreich J, and Asbell N. Bromelain: pineapple proteases with anti-edema activity. Exp Med Surg 1962;20:227-247.
  14. Kasemsuk T, Saengpetch N, Sibmooh N, Unchern S. Improved WOMAC score following 16-week treatment with bromelain for knee osteoarthritis. Clin Rheumatol. 2016 Oct;35(10):2531-40. PubMed
  15. Kutlu Ö, DemirbaS A, Elmas ÖF, Güvenç U, Metin A. Fixed drug eruption: a new side effect of bromelain. Contact Dermatitis 2020. Online ahead of print. 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 Bromelain and Metformin Together: Common Questions

Is it safe to take Bromelain with Metformin?
We do not list a known interaction between Bromelain and Metformin. 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.
Do Bromelain and Metformin have any of the same side effects?
Yes — our sources link each of them separately to 7 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Bromelain and Metformin 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 Bromelain in each. That is a conversation for your prescriber, especially if Metformin is being adjusted to a target.
How was the Bromelain and Metformin combination checked?
Interactions in our licensed database are recorded against drug classes. Metformin is filed under 5 classifications, and Bromelain has documented interactions with 2 drug classes — none of Metformin'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 Bromelain interact with any other medications?
Yes. Bromelain has 141 documented drug interactions in our database — Metformin 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 Metformin interact with any supplements?
Yes. Metformin has documented interactions with 258 supplements in our database — Bromelain is not one of them. The Metformin 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

Bromelain monograph Uses, safety profile, and every drug interaction in one place Metformin drug information The full plain-English guide to this medication Metformin supplement interactions Every supplement checked against Metformin, 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 19 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Metformin and Bromelain?

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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.