NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Prescription·Evidence index

Fish Oil and Metoprolol: what the published research says

PubMed indexes 3 records that name Fish Oil and Metoprolol together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to Fish Oil and Metoprolol. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

The research

3 studies naming Fish Oil and Metoprolol.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Efficacy and tolerability of isradipine and metoprolol in treatment of hypertension: the Finnish Isradipine Study in Hypertension (FISH).

Journal of cardiovascular pharmacology · 1992 · PMID 1381022

Clinical TrialMulticenter StudyRandomized Controlled Trial398 participants

“After 8 weeks monotherapy, mean BP (MBP) was reduced by 13/11 mm Hg (161/104 to 148/93) in the isradipine group and by 15/12 mm Hg (160/103 to 145/91) in the metoprolol group. Monotherapy with isradipine normalized DBP to less than or equal to 90 mm Hg in 52% with a mean dose of 4.26 mg daily, and monotherapy with metoprolol normalized DBP in 58% with a mean dose of 155 mg daily.1+”

Luomanmäki et al. · From the abstract

Names both Fish Oil and Metoprolol in its title.

Fish embryo toxicity of carbamazepine, diclofenac and metoprolol.

Ecotoxicology and environmental safety · 2010 · PMID 20832863

Animal study

“In conclusion, our results for carbamazepine and metoprolol are in agreement with other findings for aquatic toxicity, and also fish embryos responded in much the same way as rat embryos did. For diclofenac, the FET test performs comparably to Early Life Stage testing.”

van den Brandhof et al. · From the abstract

Names both Fish Oil and Metoprolol in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Fish Oil, Metoprolol, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.