Herb & supplement monograph

Galacto-oligosaccharides (gos) Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Galacto-oligosaccharides (gos) interacts with medications. The heart of this page is the interaction list — every drug Galacto-oligosaccharides (gos) is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Galacto-oligosaccharides (gos) is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Galacto-oligosaccharides (gos) Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Galacto-oligosaccharides (gos) drug interaction appears low for most people. None of the listed interactions are rated major, and every one of them traces back to a single, largely theoretical concern rather than proven effects in people.

Interactions deserving the most attention

The only combination that deserves real attention is with immunosuppressants, the medicines used after organ transplants and for autoimmune conditions. Because GOS may stimulate the immune system, it could in theory work against these drugs and weaken their effect. That would matter, since immunosuppressants are closely monitored medicines where even small changes count. Still, this concern is graded as possible, meaning it comes from lab, animal, or limited human research, not from documented problems in patients.

What the rest of the list means

Although the number of medications on the list looks large, they all belong to that one drug category, and the concern behind them is the same theoretical one. A long list here reflects how many individual immunosuppressant products exist, not many separate proven risks. So far, no clinically meaningful interaction has been confirmed in people.

Check your medications against Galacto-oligosaccharides (gos)

Based on HelloPharmacist’s Galacto-oligosaccharides (gos) interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Galacto-oligosaccharides (gos)

121 medications have a known interaction with Galacto-oligosaccharides (gos), graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
6-mercaptopurinePurinethol
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + 6-mercaptopurine interaction 6-mercaptopurine drug page: uses, dosage & side effects
AbrocitinibCibinqo
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Abrocitinib interaction Abrocitinib drug page: uses, dosage & side effects
AdalimumabHumira
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab interaction Adalimumab drug page: uses, dosage & side effects
Adalimumab-adazHyrimoz
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-adaz interaction
Adalimumab-adbmCyltezo
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-adbm interaction
Adalimumab-afzbAbrilada
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-afzb interaction
Adalimumab-attoAmjevita
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-atto interaction
Adalimumab-bwwdHadlima
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-bwwd interaction
Adalimumab-fkjpHulio
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Adalimumab-fkjp interaction
AlefaceptAmevive
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Alefacept interaction
AlemtuzumabCampath
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Alemtuzumab interaction Alemtuzumab drug page: uses, dosage & side effects
Anifrolumab-fniaSaphnelo
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Anifrolumab-fnia interaction Anifrolumab-fnia drug page: uses, dosage & side effects
Antithymocyte GlobulinThymoglobulin
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Antithymocyte Globulin interaction
AtezolizumabTecentriq
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Atezolizumab interaction Atezolizumab drug page: uses, dosage & side effects
AzamuneImmunoprin
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Azamune interaction
AzathioprineAzamune, Imuran
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Azathioprine interaction Azathioprine drug page: uses, dosage & side effects
BasiliximabSimulect
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Basiliximab interaction Basiliximab drug page: uses, dosage & side effects
Beclometasone DipropionateBecotide
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Beclometasone Dipropionate interaction
BeclomethasoneBeclovent, Vanceril
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Beclomethasone interaction Beclomethasone drug page: uses, dosage & side effects
Beclomethasone DipropionateQNASL, Qvar
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Beclomethasone Dipropionate interaction Beclomethasone Dipropionate drug page: uses, dosage & side effects
BetamethasoneCelestone, Diprolene AF, Diprosone
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Betamethasone interaction Betamethasone drug page: uses, dosage & side effects
Betamethasone DipropionateSernivo
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Betamethasone Dipropionate interaction Betamethasone Dipropionate drug page: uses, dosage & side effects
Betamethasone Dipropionate, CalcipotrieneEnstilar, Wynzora
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Betamethasone Dipropionate, Calcipotriene interaction
Betamethasone ValerateLuxiq
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Betamethasone Valerate interaction Betamethasone Valerate drug page: uses, dosage & side effects
Bimekizumab-bkzxBimzelx
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Bimekizumab-bkzx interaction
CiclesonideAlvesco, Omnaris, Zetonna
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Ciclesonide interaction Ciclesonide drug page: uses, dosage & side effects
CisplatinPlatinol-AQ
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Cisplatin interaction Cisplatin drug page: uses, dosage & side effects
CladribineLeustatin, Mavenclad
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Cladribine interaction Cladribine drug page: uses, dosage & side effects
CopanlisibAliqopa
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Copanlisib interaction
Cortisone AcetateCortisone Tablets, Cortone
Moderate Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full Galacto-oligosaccharides (gos) + Cortisone Acetate interaction
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Galacto-oligosaccharides (gos) combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Galacto-oligosaccharides (gos) affects

Every type of medication (drug category) Galacto-oligosaccharides (gos) is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Galacto-oligosaccharides (gos) interacts with
Immunosuppressants
Immunosuppressants

Theoretically, GOS might reduce the effects of immunosuppressants.
Human and animal studies suggest that GOS may stimulate the immune system. This could theoretically alter the effects of immunosuppressant medications.

Likelihood Possible Evidence D
Monograph

Galacto-oligosaccharides (gos): Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

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.

Part used
Carbohydrate derived from lactose (milk sugar)
Common forms
Powder, capsules, chewable tablets, added to foods, infant formula, and functional drinks
People commonly use it for
  • Prebiotic to support gut bacteria
  • Constipation
  • Digestive health
  • Immune support
  • Infant gut health

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallLikely safe

GOS is generally recognized as safe and well tolerated for most people in food amounts.

PregnancyLikely Safe

When consumed in amounts commonly found in foods.

Read the full pregnancy detail
BreastfeedingLikely Safe

When consumed in amounts commonly found in foods.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Galacto-oligosaccharides (GOS) are a type of carbohydrate made up of short chains of galactose and glucose sugars. They are a kind of prebiotic, which means they act as food for the friendly bacteria that live in your gut.

GOS are usually made from lactose, the natural sugar found in milk, using enzymes. They also occur naturally in human breast milk, where they help support a baby's developing gut. Because of this, GOS are sometimes added to infant formula along with other prebiotic fibers.

Today, GOS are sold as supplement powders and capsules, and they are also added to foods and drinks marketed for digestive health.

How it works

GOS are not digested or absorbed in the upper part of your digestive system. Instead, they pass through to the large intestine, where the bacteria living there ferment (break down) them.

This fermentation feeds beneficial bacteria like Bifidobacteria and produces compounds called short-chain fatty acids. These fatty acids may help nourish the cells lining the gut and support a healthier balance of bacteria.

Much of this understanding comes from laboratory and short-term human studies. While the prebiotic effect is fairly well established, the broader health benefits that may follow are still being studied.

Effectiveness

Does Galacto-oligosaccharides (gos) work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 22 uses evaluated
3 Possibly effective 3 Leans ineffective 16 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.
Possibly Effective Atopic dermatitis (eczema)
Rating & evidence shown verbatim from Natural Medicines

In infants at risk for atopy, providing syrup or formula containing GOS along with probiotics or fructo-oligosaccharides may reduce the risk of developing atopic dermatitis.

Possibly Effective Colic
Rating & evidence shown verbatim from Natural Medicines

Providing formula containing GOS and other ingredients may reduce the duration or frequency of crying episodes in infants with colic.

Possibly Effective Lactose intolerance
Rating & evidence shown verbatim from Natural Medicines

Oral GOS may improve some symptoms of lactose intolerance and allow for increased consumption of lactose-containing products, even after discontinuing GOS.

Possibly Ineffective Allergic rhinitis (hay fever)
Rating & evidence shown verbatim from Natural Medicines

Supplementation with oral GOS during the first 6 months of life may not prevent the development of allergic rhinitis in infants at risk for allergies.

Possibly Ineffective Food allergies
Rating & evidence shown verbatim from Natural Medicines

Supplementation with oral GOS during the first 6-12 months of life may not prevent the development of food allergies at 1 or 2 years of age.

Possibly Ineffective Upper respiratory tract infection (URTI)
Rating & evidence shown verbatim from Natural Medicines

Large studies suggest that oral GOS do not prevent the development of URTIs in healthy infants or young adults. It is unclear if GOS are beneficial for the prevention of URTIs in premature infants.

Also studied for 16 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Anxiety
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Asthma
Rating & evidence shown verbatim from Natural Medicines

It is unclear if GOS, alone or in combination with fructo-oligosaccharides, are beneficial for preventing the development of asthma or recurrent wheeze in infants at risk for allergies.

Insufficient Reliable Evidence To Rate Colorectal cancer
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GOS for the prevention of colorectal cancer, there is insufficient reliable information about the clinical effects of GOS for this purpose.

Insufficient Reliable Evidence To Rate Constipation
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS, when taken with water or added to yogurt, are beneficial in patients with constipation.

Insufficient Reliable Evidence To Rate Depression
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Diarrhea
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GOS for the prevention and treatment of diarrhea, including travelers' diarrhea, there is insufficient reliable information about the clinical effects of GOS for this purpose.

Insufficient Reliable Evidence To Rate Insomnia
Rating & evidence shown verbatim from Natural Medicines

Oral GOS have only been evaluated in combination with other ingredients; their effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Iron deficiency anemia
Rating & evidence shown verbatim from Natural Medicines

GOS increases the absorption and tolerability of iron supplements, and may therefore be beneficial in patients with iron deficiency anemia.

Insufficient Reliable Evidence To Rate Irritable bowel syndrome (IBS)
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Metabolic syndrome
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS are beneficial in patients with metabolic syndrome.

Insufficient Reliable Evidence To Rate Neonatal jaundice
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS are beneficial for the treatment of neonatal jaundice.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS improves weight loss in overweight or obese adults.

Insufficient Reliable Evidence To Rate Osteoporosis
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral GOS for osteoporosis, there is insufficient reliable information about the clinical effects of GOS for this purpose.

Insufficient Reliable Evidence To Rate Prematurity
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS are beneficial for improving cognitive or motor development in premature infants.

Insufficient Reliable Evidence To Rate Ulcerative colitis
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Urticaria
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral GOS are beneficial for the prevention of urticaria in infants.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

GOS are generally considered safe and are widely used in foods and infant formula. Most healthy people tolerate them well.

People with sensitive stomachs or conditions like IBS may want to start with a small amount, since prebiotic fibers can trigger gas and bloating. Those who are very sensitive to fermentable carbohydrates (sometimes called FODMAPs) may have more discomfort.

Pregnancy and breastfeeding: GOS are found naturally in food and in breast milk, so small dietary amounts are likely fine. However, the safety of concentrated GOS supplements during pregnancy and breastfeeding has not been well studied. To be safe, talk with your doctor before using a supplement during these times.

As with any supplement, check with your pharmacist or doctor before starting, especially if you have a chronic health condition.

Side effects

The most common side effects of GOS are digestive and tend to happen when you take too much too soon. These include:

  • Gas and bloating
  • Stomach cramps or discomfort
  • Loose stools or diarrhea

These effects are usually mild and often improve as your gut adjusts or when you lower the dose. Serious side effects are rare. If you have an allergy to milk, check the source, since GOS is often made from lactose; however, processing usually removes most milk protein.

Galacto-oligosaccharides (gos): Reported Adverse Effects

Documented safety reports on Galacto-oligosaccharides (gos) from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, GOS seem to be well tolerated in infants, children, and adults.

Most Common Adverse Effects:

Orally: Bloating, constipation, diarrhea, flatulence, and increased stool frequency.

Serious Adverse Effects (Rare):

Orally: Anaphylaxis in sensitive individuals.

Reports by condition
Atopic disease Dermatologic

Orally, 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 atopic dermatitis in one clinical study. However, most other clinical research in infants at risk of atopy shows that GOS-containing formula may actually reduce the risk of developing atopic dermatitis.

  1. 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.
  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.
  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.
  4. 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
Constipation Gastrointestinal

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.

  1. Teuri U, Korpela R. Galacto-oligosaccharides relieve constipation in elderly people. Ann Nutr Metab 1998;42(6):319-327.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
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.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

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. This gives your gut time to adjust and helps reduce gas and bloating.

Always follow the directions on the product label, and ask your pharmacist or doctor if you are unsure how much to take or how to start.

Pregnancy & Breastfeeding

Galacto-oligosaccharides (gos) & Pregnancy

Likely Safe

When consumed in amounts commonly found in foods.

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.

  1. 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

Galacto-oligosaccharides (gos) & Breastfeeding

Likely Safe

When consumed in amounts commonly found in foods.

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.

  1. 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
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

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

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
Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Pharmacist Counseling Corner

Galacto-oligosaccharides (gos): Common Questions

What is Galacto-oligosaccharides (gos) used for, and does it work?
People use Galacto-oligosaccharides (gos) for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Galacto-oligosaccharides (gos) for Atopic dermatitis (eczema), Colic and Lactose intolerance. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.
Does Galacto-oligosaccharides (gos) interact with prescription medications?
Yes. We list 121 medications with a known interaction with Galacto-oligosaccharides (gos). Use the checker above to see how Galacto-oligosaccharides (gos) interacts with a specific drug.
How are Galacto-oligosaccharides (gos) interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Galacto-oligosaccharides (gos) with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Galacto-oligosaccharides (gos) interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is GOS used for?
GOS is a prebiotic fiber used mainly to feed healthy gut bacteria and support digestion. Some people also use it for constipation and overall gut and immune health.
Is GOS the same as a probiotic?
No. A probiotic is a live beneficial bacteria, while GOS is a prebiotic, which is food that helps those good bacteria grow. They are sometimes used together.
Will GOS cause gas or bloating?
It can, especially when you first start or take a large amount. Starting with a small dose and increasing slowly usually helps reduce these effects.
Is GOS safe for children?
GOS naturally occurs in breast milk and is added to some infant formulas, so it is widely used. Still, check with your child's pediatrician before giving a supplement.

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

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