Drug & supplement interaction

Astragalus + Guselkumab

Guselkumab brand name: Tremfya.

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

Astragalus has a moderate interaction with Guselkumab. Theoretically, astragalus might interfere with immunosuppressive therapy.

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

Astragalus and Guselkumab

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

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Guselkumab

Guselkumab falls under IMMUNOSUPPRESSANTS — the group Astragalus interacts with.

Theoretically, astragalus might interfere with immunosuppressive therapy.
Astragalus seems to stimulate immune function. Theoretically, taking astragalus might decrease the effects of immunosuppressive therapy.
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 thinking behind this one. Guselkumab (Tremfya) works by quieting down a piece of your immune system that drives psoriasis and psoriatic arthritis. Astragalus, on the other hand, is traditionally used to rev the immune system up. So in theory, the two are pulling in opposite directions, and astragalus could blunt how well Tremfya controls your symptoms. That might show up as flare-ups, more of those red scaly patches coming back, or joint pain and swelling creeping in again.

I want to be honest with you, though: this is a theoretical concern based only on lab and animal research, not real-world cases. We don't have proof it actually happens in people. Still, since Tremfya is a long-term treatment you're counting on, I'd run any astragalus supplement past your pharmacist or doctor first before adding it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Upton R, ed. Astragalus Root: Analytical, quality control, and therapeutic monograph. Santa Cruz, CA: American Herbal Pharmacopoeia. 1999:1-25.
  2. Sun Y, Hersh EM, Lee SL, et al. Preliminary observations on the effects of the Chinese medicinal herbs Astragalus membranaceus and Ligustrum lucidum on lymphocyte blastogenic responses. J Biol Response Mod 1983;2:227-37..

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

Astragalus Also Interacts With Other Medications

Astragalus has 207 moderate known drug interactions in our database — the Guselkumab one above is one of them. If you take anything else, check it against the full list below.

Moderate 207 No known interaction 2,623 (incl. Guselkumab)
Taking anything else?

Check Another of Your Medications Against Astragalus

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

From our Q&A

Questions About Astragalus or Guselkumab

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Astragalus or Guselkumab, 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 Guselkumab

This page covers Astragalus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guselkumab page lists 53 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Active Hexose Correlated Compound (ahcc) (moderate), Alfalfa (moderate), American Ginseng (moderate), Andrographis (moderate) and Ashwagandha (moderate).

By severity: 52 moderate · 1 minor.

From our pharmacist’s overview on the Guselkumab page

“Guselkumab (Tremfya) quiets an overactive branch of the immune system to control psoriasis and psoriatic arthritis, and all 53 supplements on this list interact the same way, by potentially revving that system back up. None is rated major, 52 are moderate and one is minor, so for most people this reads as a watch list rather than a sto…”

Reviewed by 2 · Jul 18, 2026

Open the Guselkumab interaction page

One more smart check

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

We hold 3,437 real supplement products containing Astragalus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Astragalus. Your product may carry other ingredients that interact with Guselkumab too, on top of Astragalus — 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 Astragalus and Guselkumab 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 Astragalus
Top 5%

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

29 days ago today
Medication Guselkumab
Top 10%

#172 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 Astragalus

What is Astragalus?

Astragalus
  • Immune support
  • Colds and flu
  • Upper respiratory infections
  • Fatigue and stress (adaptogen)
  • Heart health
  • General wellness in traditional medicine

Astragalus is a root used for centuries in traditional Chinese medicine, mainly to support the immune system and help the body cope with stress. While early studies are interesting, strong human evidence for most uses is still lacking. It is generally well tolerated by healthy adults for short-term use, but should be avoided during pregnancy and breastfeeding due to limited safety data.

Read the full Astragalus monograph & all interactions
Medication

About Guselkumab Injection

What Is Guselkumab Injection Used For?

Brand name: Tremfya

Tremfya (guselkumab) injection is approved to treat adults and children 6 years of age and older who weigh at least 40 kg (about 88 lbs) with moderate-to-severe plaque psoriasis or active psoriatic arthritis. It is also approved for adults with moderately to severely active ulcerative colitis or Crohn's disease.

For plaque psoriasis and psoriatic arthritis, Tremfya is an option when systemic therapy or phototherapy is appropriate. For ulcerative colitis and Crohn's disease, Tremfya is approved for adult patients only — it has not been established as safe and effective for children with those conditions.

See full Guselkumab Injection drug information
Keep checking

Other Drugs & Astragalus

Browse every other medication we’ve checked against Astragalus — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
207Moderate
0Minor
2,622No known interaction
207 Moderate 2,622 No interaction
Moderate

207 interactions

Showing 60 of 207 moderate interactions — see all 207 on the Astragalus page.

No interaction 2,622 drugs checked — show the list

We also checked Astragalus against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,622 medications checked with no known interaction — see the full Astragalus list.

See the full Astragalus interactions page
See every supplement checked against Guselkumab, 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
Astragalus monograph › Uses, safety, and every drug interaction in one place Guselkumab supplement interactions › Every supplement checked against Guselkumab, ranked by severity Guselkumab Injection 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 Astragalus and Guselkumab Together: Common Questions

Can you take Astragalus with Guselkumab?
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 Astragalus and Guselkumab 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 Guselkumab and Astragalus?

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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.