What Fish Are Used in Fish Oil Supplements?
Fish oil typically comes from small, cold-water fatty fish rich in omega-3s like EPA and DHA. Common varieties include:
- Anchovies: The most frequent source due to high oil content, low contaminant levels, and sustainability. Brands like Nordic Naturals and Carlson Labs often specify anchovies.[1]
- Sardines: Frequently paired with anchovies for their potent omega-3 profile and minimal mercury risk.[2]
- Mackerel: Used in some products for its affordability and oil yield, though less common in premium supplements.[3]
- Herring: Popular in European brands, valued for purity in northern Atlantic stocks.[4]
Wild-caught fish from sustainable fisheries (e.g., Peru or Norway) are standard to avoid pollutants.
Why These Fish Over Others Like Salmon or Tuna?
Salmon oil exists but is rarer—farmed salmon often has lower omega-3s and higher contaminants. Tuna is avoided due to mercury buildup. Anchovies and sardines dominate because they're short-lived, low on the food chain, and yield pure, concentrated oil after molecular distillation.[5]
How to Check Fish Variety on Labels
Look for "source" or "from" on the label—reputable brands list it (e.g., "anchovy, sardine, and mackerel"). Third-party testing from NSF or USP verifies purity. If unspecified, it's often a blend of the top three.[6]
Sustainability and Contaminant Concerns
Most fish oil is certified by Friend of the Sea or MSC for sustainable sourcing. Distillation removes heavy metals; levels are far below FDA limits (e.g., <0.1 ppm mercury).[7]
[1]: Nordic Naturals Product Specs
[2]: ConsumerLab Fish Oil Review
[3]: NOW Foods Label
[4]: Carlson Labs
[5]: Harvard Health on Fish Oil Sources
[6]: USP Verification
[7]: FDA Fish Oil Guidelines