Drug & supplement interaction

Shark Cartilage + Methotrexate

Methotrexate brand names: Rheumatrex, Otrexup, Rasuvo, Reditrex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Shark Cartilage and Methotrexate in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Shark Cartilage and Methotrexate

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Methotrexate and Shark Cartilage in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Shark Cartilage safety at a glance

Shark Cartilage overall Use caution Often poorly studied, may cause digestive upset, and proven benefits are lacking.
Pregnancy Avoid Not enough safety data; avoid during pregnancy.
Breastfeeding Avoid Not enough safety data; avoid while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Methotrexate and Shark Cartilage? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methotrexate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methotrexate is filed under 6 classifications — including organic anion-transporting polypeptide substrates (oatp), organic anion transporter 3 (oat3) substrates, hepatotoxic drugs. Shark Cartilage has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Methotrexate’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Shark Cartilage Does Interact With Other Medications

Shark Cartilage has 121 moderate known drug interactions in our database — Methotrexate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Methotrexate)
Taking anything else?

Check Another of Your Medications Against Shark Cartilage

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

What to actually watch for

No Interaction Found — But Data Suggests Shark Cartilage and Methotrexate May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Shark Cartilage

    “Orally, shark cartilage can cause acute hepatitis, with symptoms including low-grade fever, jaundice, yellowing of the eyes, right upper quadrant tenderness, and elevated liver enzymes.”

    Shark Cartilage · Natural Medicines adverse-effect record, reported in hepatitis.

    1 source cited
    1. 2012. Ashar B, Vargo E. Shark cartilage-induced hepatitis [letter]. Ann Intern Med 1996;125:780-1. PubMed

    Methotrexate

    Listed in the ADVERSE REACTIONS section of the FDA label for Methotrexate. Read the label on DailyMed ›

  • Low blood pressure Additional detail

    Shark Cartilage

    “Orally, shark cartilage can cause hypotension and peripheral edema.”

    Shark Cartilage · Natural Medicines adverse-effect record, reported in hypotension.

    4 sources cited
    1. 2014. Lane IW, Comac L. Sharks don't get cancer. Garden City, NY: Avery Publishing Group; 1992.
    2. 2015. Miller DR, Anderson GT, Stark JJ, et al. Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. J Clin Oncol 1998;16:3649-55. PubMed
    3. 6716. Leitner SP, Rothkopf MM, Haverstick L, et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients (pts) with either metastatic breast or prostate cancer refractory to standard treatment. Proc Am Soc Clinical Oncol 1998;17:A240.
    4. 10900. Batist G, Patenaude F, Champagne P, et al. Neovastat (AE-941) in refractory renal cell carcinoma patients: report of a phase II trial with two dose levels. Ann Oncol 2002;13:1259-63..

    Methotrexate

    Listed in the ADVERSE REACTIONS section of the FDA label for Methotrexate. Read the label on DailyMed ›

  • Stomach upset / Nausea / Vomiting reported in 5.9% of FDA reports for Methotrexate Additional detail

    Shark Cartilage

    “Orally, shark cartilage can cause taste disturbances, nausea, vomiting, dyspepsia, constipation, cramping, and bloating.”

    Shark Cartilage · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 2014. Lane IW, Comac L. Sharks don't get cancer. Garden City, NY: Avery Publishing Group; 1992.
    2. 2015. Miller DR, Anderson GT, Stark JJ, et al. Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. J Clin Oncol 1998;16:3649-55. PubMed
    3. 6716. Leitner SP, Rothkopf MM, Haverstick L, et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients (pts) with either metastatic breast or prostate cancer refractory to standard treatment. Proc Am Soc Clinical Oncol 1998;17:A240.
    4. 10900. Batist G, Patenaude F, Champagne P, et al. Neovastat (AE-941) in refractory renal cell carcinoma patients: report of a phase II trial with two dose levels. Ann Oncol 2002;13:1259-63..
    5. 74724. Leitner SP, Rothkopf MM, Haverstick DD, and et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients with either metastatic breast or prostate cancer refractory to standard treatment. Amer Soc Clin Oncol 1998;17:A240.
    6. 74730. Rosenbluth, RJ, Jennis, AA, Cantwell, S, and et al. Oral shark cartilage in the treatment of patients with advanced primary brain tumors. A phase II pilot study (meeting abstract). Proc Annu Meet Am Soc Clin Oncol 1999;18:A554.

    Methotrexate

    Listed in the ADVERSE REACTIONS section of the FDA label for Methotrexate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Fever Additional detail

    Shark Cartilage

    Recorded for Shark Cartilage in the same Natural Medicines adverse-effect record shown under Liver problems above.

    Methotrexate

    Listed in the ADVERSE REACTIONS section of the FDA label for Methotrexate. Read the label on DailyMed ›

  • Tiredness / Dizziness reported in 6.7% of FDA reports for Methotrexate Additional detail

    Shark Cartilage

    “Orally, shark cartilage can cause dizziness, altered consciousness, decreased sensation, and fatigue.”

    Shark Cartilage · Natural Medicines adverse-effect record, reported in fatigue.

    5 sources cited
    1. 2014. Lane IW, Comac L. Sharks don't get cancer. Garden City, NY: Avery Publishing Group; 1992.
    2. 2015. Miller DR, Anderson GT, Stark JJ, et al. Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. J Clin Oncol 1998;16:3649-55. PubMed
    3. 6716. Leitner SP, Rothkopf MM, Haverstick L, et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients (pts) with either metastatic breast or prostate cancer refractory to standard treatment. Proc Am Soc Clinical Oncol 1998;17:A240.
    4. 10900. Batist G, Patenaude F, Champagne P, et al. Neovastat (AE-941) in refractory renal cell carcinoma patients: report of a phase II trial with two dose levels. Ann Oncol 2002;13:1259-63..
    5. 74725. Milner M. A guide to the use of shark cartilage in the treatment of arthritis and other inflammatory joint diseases. Amer Chiropractor 1999;21:40-42.

    Methotrexate

    Listed in the ADVERSE REACTIONS section of the FDA label for Methotrexate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Shark Cartilage but not commonly for Methotrexate: a change in taste, high blood sugar, constipation and low blood sugar.

Effects for Methotrexate come from the ADVERSE REACTIONS section of its FDA label; effects for Shark Cartilage come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 489,806 voluntary FDA FAERS reports for Methotrexate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Methotrexate Is Prescribed For, and What Shark Cartilage Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Methotrexate is a prescription medicine with approved uses on its FDA label. Shark Cartilage is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Methotrexate is prescribed for: Methotrexate treats a wide range of serious conditions. In cancer care, it is used for acute lymphoblastic leukemia, non-Hodgkin lymphoma, osteosarcoma, breast cancer, head and neck cancer, and gestational trophoblastic neoplasia (a rare tumor related to pregnancy). It is also used to prevent and treat meningeal leukemia (cancer affecting the lining of the brain and spinal cord). Outside of cancer, methotrexate is prescribed for adults with rheumatoid arthritis (RA), children with polyarticular juvenile idiopathic arthritis (a form of childhood arthritis), and adults with severe psoriasis that hasn't responded well to other treatments.

Shark Cartilage has been studied for:

  • Cancer studied, not established Shark Cartilage has been studied for this. Natural Medicines rates the evidence: Likely Ineffective Read what the research shows

    Shark Cartilage for cancer

    Most clinical research shows that oral shark cartilage is not beneficial in people with advanced cancer.

  • Psoriasis studied, not established Shark Cartilage has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Shark Cartilage for psoriasis

    It is unclear if topical shark cartilage is beneficial in patients with psoriasis.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Methotrexate on your own; if you are taking Shark Cartilage for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Shark Cartilage or Methotrexate

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

This page covers Shark Cartilage only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methotrexate page lists 82 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Beer (major), Grapefruit (major) and Siberian Cocklebur (major).

By severity: 7 major · 60 moderate · 15 minor.

From our pharmacist’s overview on the Methotrexate page

“The liver is where methotrexate and supplements clash most. Methotrexate (Rheumatrex, Otrexup, Rasuvo), used for rheumatoid arthritis, psoriasis, and certain cancers, can strain the liver on its own, and 38 of the 82 interacting ingredients on this list add liver risk of their own, alcohol included, which makes this a list to approach…”

Reviewed by 2 · Jul 18, 2026

Open the Methotrexate interaction page

One more smart check

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

We hold 2 real supplement products containing Shark Cartilage, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Shark Cartilage. Even though Shark Cartilage itself has no known interaction with Methotrexate, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Shark Cartilage and Methotrexate 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 Shark Cartilage
Top half

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

29 days ago today
Medication Methotrexate
Top 5%

#49 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Shark Cartilage reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Shark Cartilage and Methotrexate records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Shark Cartilage

What is Shark Cartilage?

  • Cancer support (popular use)
  • Arthritis and joint pain
  • Psoriasis
  • Wound healing
  • General immune support

Shark cartilage is a supplement made from the skeletal tissue of sharks that was heavily promoted for cancer and joint conditions, but good-quality clinical trials have not shown meaningful benefit. It is generally not recommended, and there are real environmental and safety concerns, so talk with your doctor or pharmacist before considering it.

Cartilage (skeletal tissue) from sharks, often from species such as the spiny dogfish and hammerhead · Capsules, tablets, powder

An interaction check asks whether these two react with each other — it does not ask whether Shark Cartilage is a good idea for someone in your situation. Here is what our Shark Cartilage record says about it on its own.

Shark Cartilage: dosing

There is no established or standardized dose for shark cartilage, and products vary widely in their content and quality. Studies have used very different amounts and forms, so no reliable recommended dose exists.If you are considering shark cartilage despite the limited evidence, follow the directions on the product label and do not exceed them.

From our Shark Cartilage monograph — the full record covers uses, side effects and every documented interaction.

Read the full Shark Cartilage monograph & all interactions
Medication

About Methotrexate

What Is Methotrexate Used For?

Brand names: Rheumatrex, Otrexup, Rasuvo, Reditrex

Methotrexate treats a wide range of serious conditions. In cancer care, it is used for acute lymphoblastic leukemia, non-Hodgkin lymphoma, osteosarcoma, breast cancer, head and neck cancer, and gestational trophoblastic neoplasia (a rare tumor related to pregnancy). It is also used to prevent and treat meningeal leukemia (cancer affecting the lining of the brain and spinal cord).

Outside of cancer, methotrexate is prescribed for adults with rheumatoid arthritis (RA), children with polyarticular juvenile idiopathic arthritis (a form of childhood arthritis), and adults with severe psoriasis that hasn't responded well to other treatments.

Most-Reported Side Effects for Methotrexate

From FAERS, the FDA’s public side-effect reporting system (489,806 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Rheumatoid arthritis 42,798 reports
Arthralgia 40,830 reports
Fatigue 33,049 reports
Nausea 28,999 reports
Joint swelling 25,026 reports
See full Methotrexate drug information
Keep checking

Other Drugs & Shark Cartilage

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

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Shark Cartilage page.

No interaction 2,708 drugs checked — show the list

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

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Shark Cartilage list.

See the full Shark Cartilage interactions page
See every supplement checked against Methotrexate, ranked by severity
Evidence & sources

Shark Cartilage References

The 12 references that drive our Shark Cartilage 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. Ashar B, Vargo E. Shark cartilage-induced hepatitis [letter]. Ann Intern Med 1996;125:780-1. PubMed
  2. Lane IW, Comac L. Sharks don't get cancer. Garden City, NY: Avery Publishing Group; 1992.
  3. Miller DR, Anderson GT, Stark JJ, et al. Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. J Clin Oncol 1998;16:3649-55. PubMed
  4. Leitner SP, Rothkopf MM, Haverstick L, et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients (pts) with either metastatic breast or prostate cancer refractory to standard treatment. Proc Am Soc Clinical Oncol 1998;17:A240.
  5. Batist G, Patenaude F, Champagne P, et al. Neovastat (AE-941) in refractory renal cell carcinoma patients: report of a phase II trial with two dose levels. Ann Oncol 2002;13:1259-63..
  6. Merly, L., Simjee, S., and Smith, S. L. Induction of inflammatory cytokines by cartilage extracts. Int Immunopharmacol. 2007;7(3):383-391. PubMed
  7. Bargahi, A., Hassan, Z. M., Rabbani, A., Langroudi, L., Noori, S. H., and Safari, E. Effect of shark cartilage derived protein on the NK cells activity. Immunopharmacol.Immunotoxicol. 2011;33(3):403-409. PubMed
  8. Leitner SP, Rothkopf MM, Haverstick DD, and et al. Two phase II studies of oral dry shark cartilage powder (SCP) in patients with either metastatic breast or prostate cancer refractory to standard treatment. Amer Soc Clin Oncol 1998;17:A240.
  9. Milner M. A guide to the use of shark cartilage in the treatment of arthritis and other inflammatory joint diseases. Amer Chiropractor 1999;21:40-42.
  10. Rosenbluth, RJ, Jennis, AA, Cantwell, S, and et al. Oral shark cartilage in the treatment of patients with advanced primary brain tumors. A phase II pilot study (meeting abstract). Proc Annu Meet Am Soc Clin Oncol 1999;18:A554.
  11. Saad F, Klotz L, Babaian R, Lacombe L, Champagne P, and Dupont E. Phase I/II trial on AE-941 (Neovastat) in patients with metastatic refractory prostate cancer (abstract presentation). Canadian Urological Association Annual Meeting (June 24-27, 2001).
  12. Merly L, Smith SL. Pro-inflammatory properties of shark cartilage supplement. Immunopharmacol Immunotoxicol. 2015;37(2):140-7. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Shark Cartilage and Methotrexate Together: Common Questions

Is it safe to take Shark Cartilage with Methotrexate?
We do not list a known interaction between Shark Cartilage and Methotrexate. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Shark Cartilage and Methotrexate have any of the same side effects?
Yes — our sources link each of them separately to 8 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Shark Cartilage and Methotrexate used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Shark Cartilage in each. That is a conversation for your prescriber, especially if Methotrexate is being adjusted to a target.
How was the Shark Cartilage and Methotrexate combination checked?
Interactions in our licensed database are recorded against drug classes. Methotrexate is filed under 6 classifications, and Shark Cartilage has documented interactions with 1 drug class — none of Methotrexate's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Shark Cartilage interact with any other medications?
Yes. Shark Cartilage has 121 documented drug interactions in our database — Methotrexate is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Methotrexate interact with any supplements?
Yes. Methotrexate has documented interactions with 82 supplements in our database — Shark Cartilage is not one of them. The Methotrexate interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Shark Cartilage monograph Uses, safety profile, and every drug interaction in one place Methotrexate drug information The full plain-English guide to this medication Methotrexate supplement interactions Every supplement checked against Methotrexate, 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 References The 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methotrexate and Shark Cartilage?

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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.