Methodology

How this site ranks fish oil, and the rules we hold ourselves to. Last reviewed July 2026.

Fish Oil Score is an independent comparison project. It exists to answer one question that "best fish oil" articles almost never answer honestly: for the omega-3 you actually get, which product costs the least per gram — and is it fresh and clean? We are not a lab and not a brand; we aggregate and rank data that certifying bodies already publish.

The core number

Every product is ranked by cost per gram of actual EPA+DHA:

cost per gram = current iHerb price ÷ (measured EPA+DHA per serving × servings per container ÷ 1000)

The word doing the work is measured. Fish-oil labels state a claim; the third-party certificate states what a lab actually found in the batch. We use the measured value, so a product that quietly over-delivers beats one with a padded label — and a "big number" label that under-delivers can't win on paper.

Where the data comes from

• Potency, freshness, purity, heavy metals: the product's public IFOS (International Fish Oil Standards, by Nutrasource) certificate for a specific tested lot. Where a product is NSF Certified for Sport instead, we note that.
• Price & servings: the current iHerb product page. Prices drift; the linked page is always the authority, and we re-check periodically.

Every row links its certificate and its product page. You never have to trust our number — click through and read the source.

Rules we don't break

• No invented numbers. If we can't verify a product's price, servings, or measured lab values from a real source, the row is marked "pending" and excluded from the ranking. We would rather show fewer products than one fabricated figure.
• No health claims. We restate published laboratory figures with attribution. We do not claim fish oil treats, prevents, or improves any condition. Talk to a clinician for that.
• The ranking isn't for sale. Some links are affiliate links and we may earn a commission if you buy through them — but order is decided purely by the cost-per-gram math, and products we can't verify don't get ranked higher for it.
• We cite marks, we don't wear them. We reference certification data as a source and reproduce published figures with attribution; we don't display certifiers' logos or imply their endorsement.

What a certificate does and doesn't prove

A third-party certificate describes one batch, at one time. It's strong evidence that a given lot met the claim, was fresh, and was low in contaminants. It is not a permanent grade and not a health guarantee. Ratings can shift batch to batch, which is exactly why the underlying numbers — not just a star — are what we show.

Corrections

Found a stale price or a number that doesn't match the linked certificate? The source wins, and we want to fix it. Every figure on this site is traceable on purpose.