Drug & supplement interaction

Cobalt + Tipiracil Hydrochloride, Trifluridine

Tipiracil Hydrochloride, Trifluridine brand name: Lonsurf.

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 Cobalt and Tipiracil Hydrochloride, Trifluridine 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 label for Tipiracil Hydrochloride, Trifluridine states a food rule worth keeping to, and 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.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Cobalt and Tipiracil Hydrochloride, Trifluridine

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 Tipiracil Hydrochloride, Trifluridine and Cobalt 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Cobalt at all — not against Tipiracil Hydrochloride, Trifluridine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Cobalt safety at a glance

Cobalt overall Avoid Inorganic cobalt supplements have no proven benefit and can cause serious toxicity, so they are generally not recommended.
Pregnancy Avoid Cobalt supplements should be avoided during pregnancy because of toxicity concerns and a lack of safety data.
Breastfeeding Avoid Avoid cobalt supplements while breastfeeding; rely on vitamin B12 for any needed cobalt.

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

Still wondering about combining Tipiracil Hydrochloride, Trifluridine and Cobalt? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Cobalt and Tipiracil Hydrochloride, Trifluridine May Share a Side Effect

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.

  • Anemia Worth acting on Additional detail

    Cobalt

    “Oral, occupational, and systemic exposure to cobalt may cause adverse ocular and otic effects. While rare, reversible and irreversible vision loss, optic neuropathy and atrophy, signs of abnormal retinal functioning, hearing loss, bilateral deafness, and tinnitus have been reported in patients taking cobalt for anemia, working in industries with exposure to cobalt dust, and those with cobalt-containing prosthetic joi…”

    Cobalt · Natural Medicines adverse-effect record, reported in anemia.

    3 sources cited
    1. 102068. Lim CA, Khan J, Chelva E, Khan R, Unsworth-Smith T. The effect of cobalt on the human eye. Doc Ophthalmol 2015;130(1):43-8. PubMed
    2. 102074. Paustenbach DJ, Galbraith DA, Finley BL. Interpreting cobalt blood concentrations in hip implant patients. Clin Toxicol (Phila) 2014;52(2):98-112. PubMed
    3. 102077. Catalani S, Rizzetti MC, Padovani A, Apostoli P. Neurotoxicity of cobalt. Hum Exp Toxicol 2012;31(5):421-37. PubMed

    “Oral, occupational, and systemic exposure to cobalt may cause cardiomyopathy. While rare, this adverse effect has been reported in patients taking cobalt for anemia, consuming cobalt-fortified beer, working in industries with exposure to cobalt dust, and those with cobalt-containing prosthetic joints.”

    Cobalt · Natural Medicines adverse-effect record, reported in anemia.

    2 sources cited
    1. 102066. Packer M. Cobalt cardiomyopathy: a critical reappraisal in light of a recent resurgence. Circ Heart Fail 2016;9(12). pii: e003604. PubMed
    2. 102076. Zywiel MG, Cherian JJ, Banerjee S, et al. Systemic cobalt toxicity from total hip arthroplasties: review of a rare condition Part 2. measurement, risk factors, and step-wise approach to treatment. Bone Joint J 2016;98-B(1):14-20. PubMed

    Tipiracil Hydrochloride, Trifluridine

    Listed in the ADVERSE REACTIONS section of the FDA label for Tipiracil Hydrochloride, Trifluridine. Read the label on DailyMed ›

Reported for Cobalt but not commonly for Tipiracil Hydrochloride, Trifluridine: a change in thyroid levels, memory problems, hearing loss and seizures.

Effects for Tipiracil Hydrochloride, Trifluridine come from the ADVERSE REACTIONS section of its FDA label; effects for Cobalt come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Tipiracil Hydrochloride, Trifluridine Products Have a Food Rule — Cobalt Should Not Break It

At least one FDA label for a product containing Tipiracil Hydrochloride, Trifluridine says to take it with food. If you take Cobalt on an empty stomach out of habit, keep them separate — and take Tipiracil Hydrochloride, Trifluridine with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Tipiracil Hydrochloride, Trifluridine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Recommended Dosage : 35 mg/m 2 /dose orally twice daily with food on Days 1 through 5 and Days 8 through 12 of each 28-day cycle.

From the Dosage and Administration section of the FDA label we read for Tipiracil Hydrochloride, Trifluridine — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Tipiracil Hydrochloride, Trifluridine

This page covers Cobalt only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tipiracil Hydrochloride, Trifluridine page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

Open the Tipiracil Hydrochloride, Trifluridine interaction page

One more smart check

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

We hold 120 real supplement products containing Cobalt, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cobalt. Even though Cobalt itself has no known interaction with Tipiracil Hydrochloride, Trifluridine, 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 Cobalt and Tipiracil Hydrochloride, Trifluridine 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 Cobalt
Steady interest

#1,045 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Tipiracil Hydrochloride, Trifluridine
Top 25%

#527 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 Cobalt reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Cobalt and Tipiracil Hydrochloride, Trifluridine 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 Cobalt

What is Cobalt?

  • Anemia (historically)
  • Part of vitamin B12 nutrition
  • General 'energy' tonics (unproven)
  • Athletic or performance claims (unproven and risky)

Cobalt is a trace element that the body only needs as part of vitamin B12 (cobalamin); there is no proven reason to take inorganic cobalt supplements, and doing so can be harmful. If you need cobalt for nutrition, get it through vitamin B12 from food or a B12 supplement, not from standalone cobalt products.

Cobalt is a chemical element (a trace mineral), not a plant part · Cobalt salts, supplement tablets (rare and discouraged), and as part of vitamin B12 (cobalamin)

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

Cobalt: dosing

There is no established safe or beneficial dose of inorganic cobalt as a dietary supplement, and health professionals generally do not recommend taking it.The cobalt your body actually needs is supplied through vitamin B12. For B12, follow the dose on the product label or your doctor's advice.

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

Read the full Cobalt monograph & all interactions
Medication

About Trifluridine and Tipiracil

What Is Trifluridine and Tipiracil Used For?

Brand name: Lonsurf

Lonsurf (trifluridine and tipiracil) is used to treat adults with metastatic colorectal cancer — either alone or combined with bevacizumab — after prior treatment with several other chemotherapy regimens and targeted therapies.

Lonsurf is also used for adults with metastatic gastric or gastroesophageal junction adenocarcinoma (cancer of the stomach or where the stomach meets the esophagus) who have already received at least two prior chemotherapy regimens.

See full Trifluridine and Tipiracil drug information
Keep checking

Other Drugs & Cobalt

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Cobalt list.

See the full Cobalt interactions page
See every supplement checked against Tipiracil Hydrochloride, Trifluridine, ranked by severity
Evidence & sources

Cobalt References

The 11 references that drive our Cobalt 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. Packer M. Cobalt cardiomyopathy: a critical reappraisal in light of a recent resurgence. Circ Heart Fail 2016;9(12). pii: e003604. PubMed
  2. Adams TN, Butt YM, Batra K, Glazer CS. Cobalt related interstitial lung disease. Respir Med 2017;129:91-7. PubMed
  3. Lim CA, Khan J, Chelva E, Khan R, Unsworth-Smith T. The effect of cobalt on the human eye. Doc Ophthalmol 2015;130(1):43-8. PubMed
  4. Guarneri F, Guarneri C, Cannavò SP. Nail-art and cobalt allergy. Contact Dermatitis 2010;62(5):320-1. PubMed
  5. Fowler JF Jr. Cobalt. Dermatitis 2016;27(1):3-8.
  6. Zajdel NJ, Smith WA, Taintor AR, Jacob SE, Olasz EB. Chemical tattoo treatment leading to systemic cobalt hypersensitivity. Skinmed 2017;15(3):221-2.
  7. Bregnbak D, Opstrup MS, Jellesen MS, Johansen JD, Thyssen JP. Allergic contact dermatitis caused by cobalt in leather - clinical cases. Contact Dermatitis 2017;76(6):366-8. PubMed
  8. Simonsen AB, Friis UF, Johansen JD, Zachariae C, Sloth JJ, Thyssen JP. Occupational allergic contact dermatitis caused by cobalt in machine oil. Contact Dermatitis 2019;80(1):59-61. PubMed
  9. Paustenbach DJ, Galbraith DA, Finley BL. Interpreting cobalt blood concentrations in hip implant patients. Clin Toxicol (Phila) 2014;52(2):98-112. PubMed
  10. Zywiel MG, Cherian JJ, Banerjee S, et al. Systemic cobalt toxicity from total hip arthroplasties: review of a rare condition Part 2. measurement, risk factors, and step-wise approach to treatment. Bone Joint J 2016;98-B(1):14-20. PubMed
  11. Catalani S, Rizzetti MC, Padovani A, Apostoli P. Neurotoxicity of cobalt. Hum Exp Toxicol 2012;31(5):421-37. 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 Cobalt and Tipiracil Hydrochloride, Trifluridine Together: Common Questions

Is it safe to take Cobalt with Tipiracil Hydrochloride, Trifluridine?
We do not list a known interaction between Cobalt and Tipiracil Hydrochloride, Trifluridine. 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 Cobalt and Tipiracil Hydrochloride, Trifluridine have any of the same side effects?
Yes — our sources link each of them separately to one 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.
Should I take Cobalt and Tipiracil Hydrochloride, Trifluridine at the same time of day?
At least one FDA label for a product containing Tipiracil Hydrochloride, Trifluridine says to take it with food. If you take Cobalt on an empty stomach out of habit, keep them separate and take Tipiracil Hydrochloride, Trifluridine with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Tipiracil Hydrochloride, Trifluridine products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Tipiracil Hydrochloride, Trifluridine interact with any supplements?
Yes. Tipiracil Hydrochloride, Trifluridine has documented interactions with 17 supplements in our database — Cobalt is not one of them. The Tipiracil Hydrochloride, Trifluridine 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

Cobalt monograph Uses, safety profile, and every drug interaction in one place Trifluridine and Tipiracil drug information The full plain-English guide to this medication Tipiracil Hydrochloride, Trifluridine supplement interactions Every supplement checked against Tipiracil Hydrochloride, Trifluridine, 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 11 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tipiracil Hydrochloride, Trifluridine and Cobalt?

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.