Drug & supplement interaction

Galacto-oligosaccharides (gos) + Mesalamine

Mesalamine brand names: Pentasa, Asacol, Canasa, Rowasa, Lialda, and others.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Galacto-oligosaccharides (gos) and Mesalamine 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 label for Mesalamine states a food rule worth keeping to, and 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

Galacto-oligosaccharides (gos) and Mesalamine

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 Mesalamine and Galacto-oligosaccharides (gos) 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.

Galacto-oligosaccharides (gos) safety at a glance

Galacto-oligosacch... overall Generally safe GOS is generally recognized as safe and well tolerated for most people in food amounts.
Pregnancy Likely Safe When consumed in amounts commonly found in foods. Read the full pregnancy detail
Breastfeeding Likely Safe When consumed in amounts commonly found in foods. 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 Mesalamine and Galacto-oligosaccharides (gos)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Mesalamine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Mesalamine is filed under a single classification — oral drugs. Galacto-oligosaccharides (gos) has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Mesalamine’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

Galacto-oligosaccharides (gos) Does Interact With Other Medications

Galacto-oligosaccharides (gos) has 121 moderate known drug interactions in our database — Mesalamine 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 Galacto-oligosaccharides (gos)

Covers the 2,830 medications we’ve checked against Galacto-oligosaccharides (gos). Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Galacto-oligosaccharides (gos) and Mesalamine 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

    Galacto-oligosaccharides (gos)

    “Orally, galacto-oligosaccharides may cause bloating, flatulence, and increased stool frequency. Giving a formula supplemented with 4 grams/L of GOS and polydextrose (1:1 ratio) to infants has been associated with an increased incidence of gastrointestinal adverse effects, primarily constipation and diarrhea, in one clinical study. However, it is unclear if this was due to GOS, polydextrose, or the combination.”

    Galacto-oligosaccharides (gos) · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 26706. Teuri U, Korpela R. Galacto-oligosaccharides relieve constipation in elderly people. Ann Nutr Metab 1998;42(6):319-327. PubMed
    2. 26709. Ziegler E, Vanderhoof JA, Petschow B, et al. Term infants fed formula supplemented with selected blends of prebiotics grow normally and have soft stools similar to those reported for breast-fed infants. J Pediatr Gastroenterol Nutr 2007;44(3):359-364. PubMed
    3. 26724. Ito M, Deguchi Y, Matsumoto K, et al. Influence of galactooligosaccharides on the human fecal microflora. J Nutr Sci Vitaminol (Tokyo) 1993;39(6):635-640. PubMed
    4. 99217. Morel FB, Dai Q, Ni J, Thomas D, Parnet P, Fança-Berthon P. a-Galacto-oligosaccharides dose-dependently reduce appetite and decrease inflammation in overweight adults. J Nutr. 2015;145(9):2052-9. PubMed
    5. 99222. Bisceglia M, Indrio F, Riezzo G, Poerio V, Corapi U, Raimondi F. The effect of prebiotics in the management of neonatal hyperbilirubinaemia. Acta Paediatr. 2009;98(10):1579-81. PubMed
    6. 106527. Colombo J, Carlson SE, Algarín C, et al. Developmental effects on sleep-wake patterns in infants receiving a cow's milk-based infant formula with an added prebiotic blend: a randomized controlled trial. Pediatr Res 2021;89(5):1222-31. PubMed

    Mesalamine

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

Reported for Galacto-oligosaccharides (gos) but not commonly for Mesalamine: constipation, a severe allergic reaction and a skin rash.

Effects for Mesalamine come from the ADVERSE REACTIONS section of its FDA label; effects for Galacto-oligosaccharides (gos) 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.

Special populations

Galacto-oligosaccharides (gos) in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When consumed in amounts commonly found in foods.

Pregnancy And Lactation Possibly Safe

When used orally. GOS have been safely used in clinical research in doses of about 4.5 grams daily from week 25 of pregnancy until delivery.

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

How to take them

Some Mesalamine Products Have a Food Rule — Galacto-oligosaccharides (gos) Should Not Break It

At least one FDA label for a product containing Mesalamine says to take it with food. If you take Galacto-oligosaccharides (gos) on an empty stomach out of habit, keep them separate — and take Mesalamine with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Mesalamine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

( 2 ) Administer mesalamine delayed-release tablets with food.

From the Dosage and Administration section of the FDA label we read for Mesalamine — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Mesalamine Is Prescribed For, and What Galacto-oligosaccharides (gos) Has Been Studied For

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

Mesalamine is prescribed for: Mesalamine is used to treat mildly to moderately active ulcerative colitis — a condition where the lining of the large intestine becomes inflamed and ulcerated. Depending on the product and formulation, it can be used to bring the disease under control (induction of remission) and/or to keep it from coming back (maintenance of remission). Different products target different parts of the lower digestive tract. Oral forms (tablets and capsules) treat the colon more broadly.

Read the rest of what Mesalamine is prescribed for

Rectal forms — including enemas (ROWASA, sfROWASA, mesalamine rectal suspension) — are used for distal ulcerative colitis, proctosigmoiditis, or proctitis (inflammation limited to the lower end of the colon or rectum). Rectal suppositories (CANASA, mesalamine rectal suppositories) are specifically for ulcerative proctitis (inflammation of the rectum only).

Galacto-oligosaccharides (gos) has been studied for:

  • Ulcerative colitis studied, not established Galacto-oligosaccharides (gos) has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Galacto-oligosaccharides (gos) for ulcerative colitis

    It is unclear if oral GOS are beneficial in patients with ulcerative colitis.

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 Mesalamine on your own; if you are taking Galacto-oligosaccharides (gos) for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Galacto-oligosaccharides (gos) or Mesalamine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Galacto-oligosaccharides (gos) or Mesalamine, 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 Mesalamine

This page covers Galacto-oligosaccharides (gos) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Mesalamine page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Mesalamine page

“Activated charcoal is the one entry here I would treat as a genuine problem for anyone taking mesalamine (Asacol, Lialda, Pentasa, and others). It is the lone major-rated interaction among the 17 on file, because charcoal soaks up drugs in the gut and can pull mesalamine out of the picture before it does its job.”

Reviewed by 2 · Jul 18, 2026

Open the Mesalamine interaction page

How much people look this up

Where Galacto-oligosaccharides (gos) and Mesalamine 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 Galacto-oligosaccharides (gos)
Steady interest

#1,265 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Mesalamine
Top 25%

#545 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 Galacto-oligosaccharides (gos) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Galacto-oligosaccharides (gos) and Mesalamine 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 Galacto-oligosaccharides (gos)

What is Galacto-oligosaccharides (gos)?

  • Prebiotic to support gut bacteria
  • Constipation
  • Digestive health
  • Immune support
  • Infant gut health

Galacto-oligosaccharides (GOS) are a type of prebiotic fiber that feed the helpful bacteria in your gut. They are generally well tolerated and may help with digestive regularity and gut balance, though they can cause gas and bloating, especially at higher doses. Evidence is promising but still limited for many uses, so talk with your pharmacist or doctor before starting.

Carbohydrate derived from lactose (milk sugar) · Powder, capsules, chewable tablets, added to foods, infant formula, and functional drinks

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

Galacto-oligosaccharides (gos): dosing

There is no single official or standardized dose for GOS. Studies have used a range of amounts, and the right dose can vary from person to person.A common, practical approach is to start with a small amount and slowly increase it over days or weeks.

From our Galacto-oligosaccharides (gos) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Galacto-oligosaccharides (gos) monograph & all interactions
Medication

About Mesalamine

What Is Mesalamine Used For?

Brand names: Pentasa, Asacol, Canasa, Rowasa, Lialda, Delzicol

Mesalamine is used to treat mildly to moderately active ulcerative colitis — a condition where the lining of the large intestine becomes inflamed and ulcerated. Depending on the product and formulation, it can be used to bring the disease under control (induction of remission) and/or to keep it from coming back (maintenance of remission).

Different products target different parts of the lower digestive tract. Oral forms (tablets and capsules) treat the colon more broadly. Rectal forms — including enemas (ROWASA, sfROWASA, mesalamine rectal suspension) — are used for distal ulcerative colitis, proctosigmoiditis, or proctitis (inflammation limited to the lower end of the colon or rectum). Rectal suppositories (CANASA, mesalamine rectal suppositories) are specifically for ulcerative proctitis (inflammation of the rectum only).

See full Mesalamine drug information
Keep checking

Other Drugs & Galacto-oligosaccharides (gos)

Browse every other medication we’ve checked against Galacto-oligosaccharides (gos) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
121Moderate
0Minor
2,708No known interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Galacto-oligosaccharides (gos) page.

No interaction 2,708 drugs checked — show the list
Evidence & sources

Galacto-oligosaccharides (gos) References

The 12 references that drive our Galacto-oligosaccharides (gos) 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. Teuri U, Korpela R. Galacto-oligosaccharides relieve constipation in elderly people. Ann Nutr Metab 1998;42(6):319-327. PubMed
  2. Kukkonen K, Savilahti E, Haahtela T, et al. Probiotics and prebiotic galacto-oligosaccharides in the prevention of allergic diseases: a randomized, double-blind, placebo-controlled trial. J Allergy Clin Immunol 2007;119(1):192-198. PubMed
  3. Moro G, Arslanoglu S, Stahl B, et al. A mixture of prebiotic oligosaccharides reduces the incidence of atopic dermatitis during the first six months of age. Arch Dis Child 2006;91(10):814-819. PubMed
  4. Ziegler E, Vanderhoof JA, Petschow B, et al. Term infants fed formula supplemented with selected blends of prebiotics grow normally and have soft stools similar to those reported for breast-fed infants. J Pediatr Gastroenterol Nutr 2007;44(3):359-364. PubMed
  5. Bakker-Zierikzee AM, Tol EA, Kroes H, et al. Faecal sIgA secretion in infants fed on pre- or probiotic infant formula. Pediatr Allergy Immunol 2006;17(2):134-140. PubMed
  6. Shadid R, Haarman M, Knol J, et al. Effects of galactooligosaccharide and long-chain fructooligosaccharide supplementation during pregnancy on maternal and neonatal microbiota and immunity--a randomized, double-blind, placebo-controlled study. Am J Clin N PubMed
  7. Vos AP, Haarman M, Buco A, et al. A specific prebiotic oligosaccharide mixture stimulates delayed-type hypersensitivity in a murine influenza vaccination model. Int Immunopharmacol 2006;6(8):1277-1286. PubMed
  8. Ito M, Deguchi Y, Matsumoto K, et al. Influence of galactooligosaccharides on the human fecal microflora. J Nutr Sci Vitaminol (Tokyo) 1993;39(6):635-640. PubMed
  9. Morel FB, Dai Q, Ni J, Thomas D, Parnet P, Fança-Berthon P. a-Galacto-oligosaccharides dose-dependently reduce appetite and decrease inflammation in overweight adults. J Nutr. 2015;145(9):2052-9. PubMed
  10. Bisceglia M, Indrio F, Riezzo G, Poerio V, Corapi U, Raimondi F. The effect of prebiotics in the management of neonatal hyperbilirubinaemia. Acta Paediatr. 2009;98(10):1579-81. PubMed
  11. Arslanoglu S, Moro GE, Schmitt J, Tandoi L, Rizzardi S, Boehm G. Early dietary intervention with a mixture of prebiotic oligosaccharides reduces the incidence of allergic manifestations and infections during the first two years of life. J Nutr. 2008;138(6 PubMed
  12. Colombo J, Carlson SE, Algarín C, et al. Developmental effects on sleep-wake patterns in infants receiving a cow's milk-based infant formula with an added prebiotic blend: a randomized controlled trial. Pediatr Res 2021;89(5):1222-31. 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 Galacto-oligosaccharides (gos) and Mesalamine Together: Common Questions

Is it safe to take Galacto-oligosaccharides (gos) with Mesalamine?
We do not list a known interaction between Galacto-oligosaccharides (gos) and Mesalamine. 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 Galacto-oligosaccharides (gos) and Mesalamine have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
Should I take Galacto-oligosaccharides (gos) and Mesalamine at the same time of day?
At least one FDA label for a product containing Mesalamine says to take it with food. If you take Galacto-oligosaccharides (gos) on an empty stomach out of habit, keep them separate and take Mesalamine with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Mesalamine products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Are Galacto-oligosaccharides (gos) and Mesalamine 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 Galacto-oligosaccharides (gos) in each. That is a conversation for your prescriber, especially if Mesalamine is being adjusted to a target.
How was the Galacto-oligosaccharides (gos) and Mesalamine combination checked?
Interactions in our licensed database are recorded against drug classes. Mesalamine is filed under 1 classification, and Galacto-oligosaccharides (gos) has documented interactions with 1 drug class — none of Mesalamine'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 Galacto-oligosaccharides (gos) interact with any other medications?
Yes. Galacto-oligosaccharides (gos) has 121 documented drug interactions in our database — Mesalamine 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 Mesalamine interact with any supplements?
Yes. Mesalamine has documented interactions with 17 supplements in our database — Galacto-oligosaccharides (gos) is not one of them. The Mesalamine interaction page linked on this page lists every one, ranked by severity.

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

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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.