Galacto-oligosaccharides (gos) + Methylnaltrexone
Methylnaltrexone brand name: Relistor.
We found no known interaction between Galacto-oligosaccharides (gos) and Methylnaltrexone 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 Methylnaltrexone 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.
Galacto-oligosaccharides (gos) and Methylnaltrexone
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 Methylnaltrexone 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
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 Methylnaltrexone
Interactions in our licensed database are recorded against drug classes, not just single drug names. Methylnaltrexone is filed under a single classification — cytochrome p450 2d6 (cyp2d6) inhibitors. Galacto-oligosaccharides (gos) has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Methylnaltrexone’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.
Galacto-oligosaccharides (gos) Does Interact With Other Medications
Galacto-oligosaccharides (gos) has 121 moderate known drug interactions in our database — Methylnaltrexone isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Galacto-oligosaccharides (gos)
We haven’t checked that one against Galacto-oligosaccharides (gos) yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Galacto-oligosaccharides (gos). Pick one to open its full report.
Galacto-oligosaccharides (gos) in Pregnancy & Breastfeeding
When consumed in amounts commonly found in foods.
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
Some Methylnaltrexone Products Have a Food Rule — Galacto-oligosaccharides (gos) Should Not Break It
At least one FDA label for a product containing Methylnaltrexone says to take it on an empty stomach. Most supplements — Galacto-oligosaccharides (gos) included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Methylnaltrexone on its own and move Galacto-oligosaccharides (gos) to a meal later in the day.
This may not be true of your version. Food instructions belong to the product, not the ingredient: two Methylnaltrexone 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.
o In patients with chronic non-cancer pain and OIC, take RELISTOR tablets with water on an empty stomach at least 30 minutes before the first meal of the day.
From the Dosage and Administration section of the FDA label we read for Methylnaltrexone — 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.
What Methylnaltrexone 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. Methylnaltrexone 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.
Methylnaltrexone is prescribed for: Methylnaltrexone, sold as Relistor, treats opioid-induced constipation (OIC) — constipation caused by opioid pain medications. Both Relistor tablets and Relistor injection are approved for adults with chronic non-cancer pain, including those with pain related to a prior cancer or its treatment who do not need frequent opioid dose increases. Relistor injection is also approved for adults with advanced illness or active cancer pain who require increasing opioid doses as part of palliative care.
Galacto-oligosaccharides (gos) has been studied for:
-
Constipation 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 constipation
It is unclear if oral GOS, when taken with water or added to yogurt, are beneficial in patients with constipation.
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 Methylnaltrexone 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.
See Every Supplement That Interacts With Methylnaltrexone
This page covers Galacto-oligosaccharides (gos) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylnaltrexone page lists 3 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Fever Bark (moderate), Iboga (moderate) and Yohimbe (moderate).
By severity: 3 moderate.
From our pharmacist’s overview on the Methylnaltrexone page
“If you take methylnaltrexone (Relistor) for opioid-induced constipation, the supplement list to know is short: three ingredients, all rated moderate, none major. Yohimbe, fever bark, and iboga are all cleared by the same liver enzyme, CYP2D6, and methylnaltrexone can slow that enzyme, letting their active compounds build up in your blood.”
Reviewed by 2 · Jul 18, 2026
Where Galacto-oligosaccharides (gos) and Methylnaltrexone 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.
#1,264 of 1,452 supplements looked up here in the last 7 days
#2,316 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 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 Methylnaltrexone 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.
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.
About Methylnaltrexone
What Is Methylnaltrexone Used For?
Brand name: Relistor
Methylnaltrexone, sold as Relistor, treats opioid-induced constipation (OIC) — constipation caused by opioid pain medications. Both Relistor tablets and Relistor injection are approved for adults with chronic non-cancer pain, including those with pain related to a prior cancer or its treatment who do not need frequent opioid dose increases.
Relistor injection is also approved for adults with advanced illness or active cancer pain who require increasing opioid doses as part of palliative care.
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.
No drugs match “”.
121 interactions
- Hydrocortisone ›
- Prednisone ›
- Cyclosporine ›
- Dexamethasone ›
- Prednisolone ›
- Tacrolimus ›
- Triamcinolone ›
- Betamethasone ›
- Ciclesonide ›
- Azathioprine ›
- Beclomethasone ›
- Beclomethasone Dipropionate ›
- Cladribine ›
- Cortisone Acetate ›
- Cyclophosphamide ›
- Daclizumab ›
- Denosumab ›
- Fingolimod ›
- Methylprednisolone ›
- Tofacitinib ›
- Triamcinolone Acetonide ›
- 6-mercaptopurine ›
- Abatacept ›
- Abrocitinib ›
- Adalimumab ›
- Adalimumab-adaz ›
- Adalimumab-adbm ›
- Adalimumab-afzb ›
- Adalimumab-atto ›
- Adalimumab-bwwd ›
- Adalimumab-fkjp ›
- Alefacept ›
- Alemtuzumab ›
- Anifrolumab-fnia ›
- Antithymocyte Globulin ›
- Atezolizumab ›
- Azamune ›
- Basiliximab ›
- Beclometasone Dipropionate ›
- Betamethasone Dipropionate ›
- Betamethasone Valerate ›
- Bimekizumab-bkzx ›
- Cisplatin ›
- Copanlisib ›
- Deflazacort ›
- Deucravacitinib ›
- Diroximel Fumarate ›
- Durvalumab ›
- Eculizumab ›
- Efalizumab ›
- Efgartigimod Alfa-fcab ›
- Elranatamab ›
- Emapalumab-lzsg ›
- Epcoritamab-bysp ›
- Etanercept ›
- Etanercept-szzs ›
- Etanercept-ykro ›
- Etrasimod ›
- Fludrocortisone ›
- Fluorouracil (iv) ›
Showing 60 of 121 moderate interactions — see all 121 on the Galacto-oligosaccharides (gos) page.
No interaction 2,708 drugs checked — show the list
We also checked Galacto-oligosaccharides (gos) against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Ivermectin ›
- Metoprolol ›
- Aspirin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Acetaminophen ›
- Escitalopram ›
- Tadalafil ›
- Clopidogrel ›
- Abemaciclib ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Valacyclovir ›
- Ibuprofen ›
- Tirzepatide ›
- Methamphetamine ›
- Warfarin Sodium ›
- Semaglutide ›
- Sumatriptan ›
- Propranolol ›
- Lisdexamfetamine ›
- Metformin ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Bendamustine ›
- Amitriptyline ›
- Acyclovir ›
- Methotrexate ›
- Doxycycline ›
- Fluoxetine ›
- Amphetamine ›
- Lamotrigine ›
- Pregabalin ›
- Acetaminophen, Codeine ›
- Azithromycin ›
- Gabapentin ›
- Dextroamphetamine ›
- Isotretinoin ›
- Clonazepam ›
- Methylene Blue ›
- Omeprazole ›
- Amlodipine Besylate ›
- Quetiapine ›
- Letrozole ›
- Duloxetine ›
- Naproxen ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Bisoprolol ›
Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Galacto-oligosaccharides (gos) list.
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.
- Teuri U, Korpela R. Galacto-oligosaccharides relieve constipation in elderly people. Ann Nutr Metab 1998;42(6):319-327. PubMed
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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.
Taking Galacto-oligosaccharides (gos) and Methylnaltrexone Together: Common Questions
Is it safe to take Galacto-oligosaccharides (gos) with Methylnaltrexone?
Do Galacto-oligosaccharides (gos) and Methylnaltrexone have any of the same side effects?
Should I take Galacto-oligosaccharides (gos) and Methylnaltrexone at the same time of day?
Are Galacto-oligosaccharides (gos) and Methylnaltrexone used for the same thing?
How was the Galacto-oligosaccharides (gos) and Methylnaltrexone combination checked?
Does Galacto-oligosaccharides (gos) interact with any other medications?
Does Methylnaltrexone interact with any supplements?
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.