Drug & supplement interaction

Calanus Oil + Fosfomycin

Fosfomycin brand name: Monurol.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Calanus Oil and Fosfomycin 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.

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Interaction report

Calanus Oil and Fosfomycin

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 Fosfomycin and Calanus Oil 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 Calanus Oil at all — not against Fosfomycin, 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.

Calanus Oil safety at a glance

Calanus Oil overall Use caution Generally well tolerated in early studies, but long-term safety data in people are limited.
Pregnancy Avoid There is not enough safety information, so it is best to avoid during pregnancy.
Breastfeeding Avoid Safety during breastfeeding has not been established, so avoid unless your doctor advises otherwise.

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

Still wondering about combining Fosfomycin and Calanus Oil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Calanus Oil Itself Has Been Linked To

This is not an interaction — nothing below involves Fosfomycin. It is the side-effect record for Calanus Oil on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Calanus Oil, this list is the first place to look.

  • A skin rash Additional detail

    “Calanus oil seems to be well tolerated. In one safety study, taking calanus oil for 12 months was reported to cause a higher rate of mild atopic dermatitis (eczema) when compared with placebo.”

    Calanus Oil · Natural Medicines adverse-effect record, reported in dermatitis.

    3 sources cited
    1. 97880. Cook CM, Larsen TS, Derrig LD, Kelly KM, Tande KS. Wax ester rich oil from the marine crustacean, Calanus finmarchicus, is a bioavailable source of EPA and DHA for human consumption. Lipids. 2016;51(10):1137-1144.
    2. 97881. Tande KS, Vo TD, Lynch BS. Clinical safety evaluation of marine oil derived from Calanus finmarchicus. Regul Toxicol Pharmacol. 2016;80:25-31. PubMed
    3. 105408. Dadová K, Petr M, Steffl M, et al. Effect of calanus oil supplementation and 16 week exercise program on selected fitness parameters in older women. Nutrients. 2020 Feb 14;12(2):481. PubMed

    “Orally, calanus oil is associated with more reports of mild atopic dermatitis (eczema) over a 12-month period when compared with placebo.”

    Calanus Oil · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 97881. Tande KS, Vo TD, Lynch BS. Clinical safety evaluation of marine oil derived from Calanus finmarchicus. Regul Toxicol Pharmacol. 2016;80:25-31. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Calanus Oil — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Fosfomycin’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Fosfomycin column appears here.

Everything else you take

See Every Supplement That Interacts With Fosfomycin

This page covers Calanus Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fosfomycin page lists 44 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Bacillus Coagulans (moderate), Bacillus Subtilis (moderate), Bifidobacterium Animalis Subsp. Lactis (moderate) and Bifidobacterium Bifidum (moderate).

By severity: 1 major · 33 moderate · 10 minor.

From our pharmacist’s overview on the Fosfomycin page

“Fosfomycin (Monurol) is often given as a single sachet to knock out a bladder infection, so you get one chance to absorb the full dose, and that is exactly where this list deserves real care. The clearest hazard is activated charcoal, which binds medicines in the gut and can cut how much fosfomycin your body actually takes in.”

Reviewed by 2 · Jul 18, 2026

Open the Fosfomycin interaction page

How much people look this up

Where Calanus Oil and Fosfomycin 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 Calanus Oil
Steady interest

#1,232 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fosfomycin
Steady interest

#1,922 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 Calanus Oil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Calanus Oil and Fosfomycin 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 Calanus Oil

What is Calanus Oil?

  • Heart and metabolic health
  • Source of omega-3 fatty acids
  • Anti-inflammatory support
  • General wellness
  • Exercise and weight management

Calanus oil is a marine omega-3 oil made from a small Arctic zooplankton (Calanus finmarchicus). It is rich in omega-3 fatty acids bound in a unique 'wax ester' form, and early research suggests possible benefits for metabolic and heart health, but the evidence is still preliminary. Talk with your pharmacist or doctor before using it, especially if you have a seafood allergy or are pregnant.

Calanus finmarchicus · Calanidae · Oil extracted from the whole copepod (a tiny marine zooplankton) · Softgel capsules, oil

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

Calanus Oil: dosing

There is no official, standardized dose of calanus oil. Studies have used a fairly small daily amount, often just a gram or two per day, but products and concentrations vary.The best approach is to follow the dose printed on the product label and not exceed it.

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

Read the full Calanus Oil monograph & all interactions
Medication

About Fosfomycin

What Is Fosfomycin Used For?

Brand name: Monurol

Fosfomycin is an antibiotic used to treat urinary tract infections (UTIs) caused by specific bacteria. The right form depends on how serious the infection is.

Oral forms (Fosfomycin Tromethamine and Monurol) are approved only for uncomplicated UTIs — also called acute cystitis — in women 18 and older, caused by E. coli or Enterococcus faecalis. They are not for kidney infections or abscesses around the kidney. Contepo (intravenous) is approved for adults 18 and older with complicated UTIs, including acute pyelonephritis (kidney infection), caused by susceptible E. coli or Klebsiella pneumoniae.

See full Fosfomycin drug information
Keep checking

Other Drugs & Calanus Oil

Browse every other medication we’ve checked against Calanus Oil — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Calanus Oil References

The 3 references that drive our Calanus Oil 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. Cook CM, Larsen TS, Derrig LD, Kelly KM, Tande KS. Wax ester rich oil from the marine crustacean, Calanus finmarchicus, is a bioavailable source of EPA and DHA for human consumption. Lipids. 2016;51(10):1137-1144.
  2. Tande KS, Vo TD, Lynch BS. Clinical safety evaluation of marine oil derived from Calanus finmarchicus. Regul Toxicol Pharmacol. 2016;80:25-31. PubMed
  3. Dadová K, Petr M, Steffl M, et al. Effect of calanus oil supplementation and 16 week exercise program on selected fitness parameters in older women. Nutrients. 2020 Feb 14;12(2):481. 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 Calanus Oil and Fosfomycin Together: Common Questions

Is it safe to take Calanus Oil with Fosfomycin?
We do not list a known interaction between Calanus Oil and Fosfomycin. 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.
Does Fosfomycin interact with any supplements?
Yes. Fosfomycin has documented interactions with 44 supplements in our database — Calanus Oil is not one of them. The Fosfomycin interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Fosfomycin and Calanus Oil?

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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.