Drug & supplement interaction

Ligandrol + Fostamatinib

Fostamatinib brand name: Tavalisse.

Moderate Interaction
The bottom line Moderate

Ligandrol has a moderate interaction with Fostamatinib. Theoretically, concomitant use might have additive hepatotoxic effects.

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

Ligandrol and Fostamatinib

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Fostamatinib

Fostamatinib falls under HEPATOTOXIC DRUGS — the group Ligandrol interacts with.

Theoretically, concomitant use might have additive hepatotoxic effects.
In case reports, patients were diagnosed with liver injury thought to be related to the use of products containing ligandrol.
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 concern with pairing these two. Fostamatinib (Tavalisse) can raise your liver enzymes on its own, which is why your doctor checks bloodwork while you're on it. Ligandrol has its own history too, with real case reports of people developing liver injury after using products that contain it. Put them together and you may be stacking two liver stressors at once, which could make liver trouble more likely.

To be fair, this is based on scattered case reports rather than strong studies, so it's more of a caution than a guarantee. Still, Ligandrol is an unapproved SARM that isn't a true supplement, and I wouldn't combine it with Tavalisse without talking to your doctor or pharmacist first. Watch for yellowing skin or eyes, dark urine, belly pain, or unusual tiredness.

References
  1. Barbara M, Dhingra S, Mindikoglu AL. Drug-induced liver injury associated with alpha bolic (RAD-140) and alpha elite (RAD-140 and LGD-4033). ACG Case Rep J 2020;7(6):e00409. PubMed
  2. Barbara M, Dhingra S, Mindikoglu AL. Ligandrol (LGD-4033)-Induced Liver Injury. ACG Case Rep J 2020;7(6):e00370. PubMed
  3. Koller T, Vrbova P, Meciarova I, et al. Liver injury associated with the use of selective androgen receptor modulators and post-cycle therapy: Two case reports and literature review. World J Clin Cases 2021;9(16):4062-4071. PubMed
  4. Flores JE, Chitturi S, Walker S. Drug-induced liver injury by selective androgenic receptor modulators. Hepatol Commun. 2020;4(3):450-452. 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

Ligandrol Also Interacts With Other Medications

Ligandrol has 369 moderate known drug interactions in our database — the Fostamatinib one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Ligandrol

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

Everything else you take

See Every Supplement That Interacts With Fostamatinib

This page covers Ligandrol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fostamatinib page lists 209 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 167 moderate · 36 minor.

From our pharmacist’s overview on the Fostamatinib page

“I would treat the supplement list for fostamatinib (Tavalisse), a medicine that raises platelet counts in chronic immune thrombocytopenia, with real care. Most of what shows up here involves CYP3A4, the liver enzyme that clears fostamatinib, so grapefruit can drive its blood level up while St.”

Reviewed by 2 · Jul 18, 2026

Open the Fostamatinib interaction page

One more smart check

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

We hold 26 real supplement products containing Ligandrol, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ligandrol. Your product may carry other ingredients that interact with Fostamatinib too, on top of Ligandrol — 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 Ligandrol and Fostamatinib 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 Ligandrol
Top half

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

29 days ago today
Medication Fostamatinib
Top 25%

#353 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 Ligandrol

What is Ligandrol?

  • Muscle building
  • Athletic performance and strength
  • Body recomposition
  • Bodybuilding cycles

Ligandrol (LGD-4033) is a synthetic selective androgen receptor modulator (SARM), not a natural herb or approved dietary supplement. It is not approved for human use, is banned in sports, and has been linked to liver injury and hormonal disruption, so it should not be taken as a supplement.

Read the full Ligandrol monograph & all interactions
Medication

About Fostamatinib

What Is Fostamatinib Used For?

Brand name: Tavalisse

Tavalisse (fostamatinib) is used to treat thrombocytopenia — dangerously low platelet counts — in adults with chronic immune thrombocytopenia (ITP). It is specifically for people whose platelet counts have not improved enough with at least one earlier ITP treatment.

The goal is to raise platelet counts high enough to reduce the risk of serious bleeding. If platelet counts do not respond sufficiently after 12 weeks, the medication is typically stopped.

See full Fostamatinib drug information
Keep checking

Other Drugs & Ligandrol

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

0Major
369Moderate
0Minor
2,460No known interaction
Moderate

369 interactions

Showing 60 of 369 moderate interactions — see all 369 on the Ligandrol page.

No interaction 2,460 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Ligandrol and Fostamatinib Together: Common Questions

Can you take Ligandrol with Fostamatinib?
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 Ligandrol and Fostamatinib 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 Fostamatinib and Ligandrol?

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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.