Drug & supplement interaction

Larch Arabinogalactan + Ritlecitinib

Ritlecitinib brand name: Litfulo.

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

Larch Arabinogalactan has a moderate interaction with Ritlecitinib. Theoretically, larch arabinogalactan might interfere with immunosuppression therapy due to immunostimulant effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Larch Arabinogalactan and Ritlecitinib

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

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Ritlecitinib

Ritlecitinib falls under IMMUNOSUPPRESSANTS — the group Larch Arabinogalactan interacts with.

Theoretically, larch arabinogalactan might interfere with immunosuppression therapy due to immunostimulant effects. Immunosuppressant drugs include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and other drugs.
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 pairing larch arabinogalactan with Litfulo (ritlecitinib). Ritlecitinib is a JAK/TEC inhibitor that works by calming down an overactive immune system, which is how it helps regrow hair in severe alopecia areata. Larch arabinogalactan, on the other hand, may gently stimulate parts of the immune system. So in theory, the fiber could nudge your immune activity in the opposite direction from what the drug is trying to do, and possibly make ritlecitinib work a little less well.

I want to be honest about the strength of this: it's purely theoretical, based on how each one behaves, not on real cases in people taking them together. This isn't about ritlecitinib building up or causing more side effects. Before adding this supplement, just run it by your pharmacist or dermatologist so they can weigh in for your situation.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. D'Adamo P. Larch arabinogalactan. J Naturopath Med 1996;6:33-7.
  2. Kelly GS. Larch arabinogalactan: Clinical relevance of a novel immune-enhancing polysaccharide. Alt Med Rev 1999;4:96-103.
  3. Dion C, Chappuis E, Ripoll C. Does larch arabinogalactan enhance immune function? A review of mechanistic and clinical trials. Nutr Metab (Lond) 2016;13:28. 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

Larch Arabinogalactan Also Interacts With Other Medications

Larch Arabinogalactan has 120 moderate known drug interactions in our database — the Ritlecitinib 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. Ritlecitinib)
Taking anything else?

Check Another of Your Medications Against Larch Arabinogalactan

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

Everything else you take

See Every Supplement That Interacts With Ritlecitinib

This page covers Larch Arabinogalactan only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ritlecitinib page lists 192 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Active Hexose Correlated Compound (ahcc) (moderate).

By severity: 3 major · 151 moderate · 38 minor.

From our pharmacist’s overview on the Ritlecitinib page

“For anyone on ritlecitinib (Litfulo), the immune-calming pill for severe alopecia areata, I would treat this page with real care, starting with its three major-rated entries. Grapefruit and St.”

Reviewed by 2 · Jul 18, 2026

Open the Ritlecitinib interaction page

One more smart check

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

We hold 717 real supplement products containing Larch Arabinogalactan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Larch Arabinogalactan. Your product may carry other ingredients that interact with Ritlecitinib too, on top of Larch Arabinogalactan — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Larch Arabinogalactan and Ritlecitinib 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 Larch Arabinogalactan
Top 25%

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

29 days ago today
Medication Ritlecitinib
Steady interest

#2,533 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 Larch Arabinogalactan

What is Larch Arabinogalactan?

  • Immune support
  • Cold and flu prevention
  • Digestive and gut health
  • Source of soluble fiber
  • Prebiotic support

Larch arabinogalactan is a soluble fiber from larch trees that is mainly used as a prebiotic and for immune support. Early research is interesting but limited, and most claims are not yet firmly proven. It is generally well tolerated, but pregnant and breastfeeding people should be cautious and check with a healthcare provider first.

Read the full Larch Arabinogalactan monograph & all interactions
Keep checking

Other Drugs & Larch Arabinogalactan

Browse every other medication we’ve checked against Larch Arabinogalactan — 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 Larch Arabinogalactan page.

No interaction 2,709 drugs checked — show the list

We also checked Larch Arabinogalactan 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 Larch Arabinogalactan list.

See the full Larch Arabinogalactan interactions page
See every supplement checked against Ritlecitinib, 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
Larch Arabinogalactan monograph › Uses, safety, and every drug interaction in one place Ritlecitinib supplement interactions › Every supplement checked against Ritlecitinib, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Larch Arabinogalactan and Ritlecitinib Together: Common Questions

Can you take Larch Arabinogalactan with Ritlecitinib?
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 Larch Arabinogalactan and Ritlecitinib 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 Ritlecitinib and Larch Arabinogalactan?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.