Drug & supplement interaction

Galacto-oligosaccharides (gos) + Tacrolimus

Tacrolimus brand names: Prograf (capsule), Prograf (injectable), Protopic, Prograf XL, Astagraf XL, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Galacto-oligosaccharides (gos) has a moderate interaction with Tacrolimus. Theoretically, GOS might reduce the effects of immunosuppressants.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Galacto-oligosaccharides (gos) and Tacrolimus

Here is the interaction we found between these two, with the evidence behind it.

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Tacrolimus

Tacrolimus falls under IMMUNOSUPPRESSANTS — the group Galacto-oligosaccharides (gos) interacts with.

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.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the idea behind this one. Tacrolimus works by quieting your immune system so it doesn't attack your transplanted organ. GOS, a prebiotic fiber, may gently nudge your immune system in the opposite direction by feeding helpful gut bacteria. So on paper, the two are pulling in different directions, and the worry is that GOS could slightly blunt how well tacrolimus holds your immune system back.

I want to be honest about how shaky this is. This is a theoretical concern based on how things work in the lab and in some animal and human studies, not proof that it actually causes transplant rejection. Still, because tacrolimus is a high-stakes, narrow-margin drug, please loop in your transplant team or pharmacist before adding a GOS supplement so they can keep an eye on your levels.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. 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

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Galacto-oligosaccharides (gos) Also Interacts With Other Medications

Galacto-oligosaccharides (gos) has 120 moderate known drug interactions in our database — the Tacrolimus one above is one of them. If you take anything else, check it against the full list below.

Moderate 120 No known interaction 2,710 (incl. Tacrolimus)
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.

From our Q&A

Questions About Galacto-oligosaccharides (gos) or Tacrolimus

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 Tacrolimus, 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 Tacrolimus

This page covers Galacto-oligosaccharides (gos) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tacrolimus page lists 202 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Asarabacca (major) and Cesium (major).

By severity: 11 major · 152 moderate · 39 minor.

From our pharmacist’s overview on the Tacrolimus page

“Tacrolimus (Prograf, Astagraf XL, Envarsus XR) keeps a transplanted organ from being rejected, and it works inside a narrow blood-level window, meaning even small shifts can invite rejection or toxicity. That makes these 202 supplement interactions worth real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Tacrolimus interaction page

How much people look this up

Where Galacto-oligosaccharides (gos) and Tacrolimus 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

#1,233 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Tacrolimus
Top 25%

#427 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.

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.

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

About Tacrolimus

What Is Tacrolimus Used For?

Brand names: Prograf (capsule), Prograf (injectable), Protopic, Prograf XL, Astagraf XL, Envarsus XR

Tacrolimus is prescribed to help prevent your body from rejecting a transplanted organ. It is used in adults who receive a kidney, liver, or heart transplant, and in children who receive a liver transplant. It is always used alongside other anti-rejection medicines.

Because tacrolimus works by dampening your immune system, it lowers the risk of your body attacking the new organ — but it also means you need to be watched closely for infections and other side effects throughout your treatment.

See full Tacrolimus 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
120Moderate
0Minor
2,709No known interaction
120 Moderate 2,709 No interaction
Moderate

120 interactions

Showing 60 of 120 moderate interactions — see all 120 on the Galacto-oligosaccharides (gos) page.

No interaction 2,709 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.

Showing the 60 most looked-up of 2,709 medications checked with no known interaction — see the full Galacto-oligosaccharides (gos) list.

See the full Galacto-oligosaccharides (gos) interactions page
See every supplement checked against Tacrolimus, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Galacto-oligosaccharides (gos) monograph › Uses, safety, and every drug interaction in one place Tacrolimus supplement interactions › Every supplement checked against Tacrolimus, ranked by severity Tacrolimus drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Galacto-oligosaccharides (gos) and Tacrolimus Together: Common Questions

Can you take Galacto-oligosaccharides (gos) with Tacrolimus?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Galacto-oligosaccharides (gos) and Tacrolimus interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Tacrolimus and Galacto-oligosaccharides (gos)?

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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.