Short answer
There is no consumer test that crowns a winner among liquid omega-3 oils. In the UK, Which? published an omega-3 supplement assessment (tested May 2026) that scores mainly capsules on EPA+DHA dose and additives; the top scorers are visible to members only. In Germany, Stiftung Warentest last tested omega-3 supplements in June 2020 and named no winner — it rated them "superfluous" for preventing cardiovascular disease. None of these tests measured what matters for you personally: your own omega-3 level (status: 31.10.2026).
Transparency
omega3-test.net is not a testing organisation and has not carried out its own laboratory tests. We are an Eqology partner and earn a commission on orders placed via our partner links. Every figure on this page names its source.
Test results rate products, not your supply. That is what the Omega-3 Index measures.
Test your Omega-3 Index →Which? 2026: dose and additives, mostly capsules
Which? assessed popular omega-3 supplements sold in the UK (date tested: May 2026, page last checked July 2026). The visible product list consists mainly of capsules — supermarket and pharmacy own brands, Bioglan, Nutravita, Dr.Vegan and Bare Biology's 1,700 mg capsules.
How Which? scores
- Dose: EPA+DHA per daily dose, scored against 450 mg for "maintenance" products and 1,000 mg for products labelled "high strength". Total fish oil content is not counted.
- Additives: fillers and extras; an antioxidant against rancidity counts as necessary.
- Lab check: products Which? plans to recommend are tested in an accredited laboratory to confirm the declared dose; independent purity certifications are checked.
Oxidation values such as TOTOX are not part of the published scoring method, and the liquid oils compared on our site (Norsan, Eqology, Bare Biology liquid) do not appear in the visible list. The scores and recommendations themselves are only available to Which? members.
Germany: Stiftung Warentest 2020 and ÖKO-TEST
The two big German consumer testers are often quoted on UK and international sites too:
- Stiftung Warentest, test 06/2020: 20 supplements (14 fish oil, 4 algae oil, 2 linseed oil) and 3 over-the-counter medicines. Products were checked in the lab, including for contaminants, and press coverage reported hardly any lab findings. The verdict: the supplements are "superfluous" for protection against cardiovascular disease, as the benefit is not sufficiently proven. No ranking, no winner (Stiftung Warentest press release, 26.05.2020). No newer test has been published (status: 31.10.2026).
- ÖKO-TEST 7/2012: 25 products (4 medicines, 21 supplements); all supplements were downgraded by two grades for doubtful benefit, so the top grade went to a medicine (testberichte.de). In its 2017 yearbook, ÖKO-TEST tested eleven krill and algae oil capsules — none better than "satisfactory" (oekotest.de, 20.10.2016).
What the tests did not measure: the Omega-3 Index
Consumer tests rate products. Whether people actually have enough EPA and DHA in their bodies is a different question — and it can be measured with the Omega-3 Index, the share of EPA and DHA in red blood cell membranes. Stiftung Warentest did not look at it; instead it referred to the German Nutrition Society, according to which people in Germany are adequately supplied with plant-based omega-3 fatty acids (press release, 26.05.2020). That refers to alpha-linolenic acid from plants, not EPA and DHA.
Studies that measured the Omega-3 Index show a different picture:
| Study | Who was measured? | Result |
|---|---|---|
| Rein et al. 2020 | 500 BASF employees in Germany, aged 21–64 | Mean 4.1 %; 99.6 % below 8 % (Nutrients, PMID 33113826) |
| Gellert et al. 2017 | 446 German women aged 40–60 (VitaMinFemin study) | Mean 5.49 %; 62.8 % between 4 and 6 % (PLEFA, PMID 28237088); 97.3 % below 8 % (NutraIngredients, 27.01.2017) |
| von Schacky et al. 2014 | 106 German national-squad winter endurance athletes | 105 of 106 below 8 % (Int J Sport Nutr Exerc Metab, PMID 25203220) |
| Torrissen et al. 2025 | More than 590,000 dried blood spot tests worldwide (whole blood) | Low omega-3 levels common worldwide, including among people taking omega-3 supplements (Lipids Health Dis, PMID 40783537); authors are affiliated with Zinzino and the laboratory Vitas |
In all three German studies, more than 9 out of 10 participants were below 8 % — the lower end of the 8–11 % target range proposed by Harris and von Schacky (Preventive Medicine 2004, PMID 15208005).
We are surprised how rarely these measurements appear in press coverage of consumer tests. "Superfluous for preventing cardiovascular disease" is often retold as "nobody needs omega-3". That is not what the test examined. It assessed whether capsules prevent disease — not whether people's EPA and DHA levels are sufficient. These are two different questions, and the second one can be measured.
Putting this in context
- 8–11 % is a target range proposed in research, not an official reference value of the NHS, SACN or EFSA.
- The studies above measured specific groups in Germany; they are not a representative sample, and we found no comparable UK study for this page.
- Clemens von Schacky, co-author of the target range, works for the testing laboratory Omegametrix; the authors of the 2025 study are affiliated with Zinzino. We have an interest too: we are an Eqology partner.
- A low Omega-3 Index is not a diagnosis. Whether and how much you should supplement is best decided with a measurement and, if you have questions, with your GP.
Where do all the "best omega-3" lists come from?
- Comparison and review sites with their own rankings — often without lab analysis and often paid by commission on purchases.
- News articles that turn an old test into a "top 3" list, even if the tester never produced a ranking.
- Paywalled scores such as Which?'s, quoted second-hand without the scoring criteria.
How to check a "test winner" claim
- Who tested? A consumer organisation or a site with its own ranking?
- When? Is the test date given?
- Which product? Exactly this product and formula — or just the brand?
- What was measured? Dose only, or also oxidation and contaminants?
What counts instead
| Criterion | What it shows | Where to find it |
|---|---|---|
| IFOS report | Measured values per batch: EPA/DHA, oxidation (TOTOX), heavy metals, PCBs, dioxins | Free in the IFOS database (certifications.nutrasource.ca) |
| TOTOX of the finished product | How fresh the oil you actually buy is; the IFOS limit is 19.5 | IFOS report or the manufacturer's certificate of analysis |
| EPA+DHA per daily dose | Whether the amount matches the EFSA health claims (250 mg for normal heart function) | Label |
| Omega-3 Index | Your own status: share of EPA and DHA in red blood cells | Dried blood spot test with lab analysis |
IFOS used to award up to 5 stars; current IFOS reports no longer contain a star rating but list the measured values and a pass for each batch (IFOS reports, checked 31.10.2026). For TOTOX values of well-known oils, see our TOTOX comparison. Five liquid oils checked against IFOS reports and label data: best omega-3 oil UK 2026. How to measure your own level: Omega-3 Index test.
Frequently Asked Questions
Is there an omega-3 test winner in the UK?
Not for liquid omega-3 oils. Which? assessed popular omega-3 supplements (tested May 2026), mainly capsules, scoring EPA+DHA dose and additives; the top scorers are visible to members only. Stiftung Warentest in Germany last tested omega-3 supplements in June 2020 and named no winner.
What does Which? test in omega-3 supplements?
Which? scores the EPA+DHA dose per day against 450 mg for maintenance products and 1,000 mg for products labelled high strength, and rates fillers and additives. Products it plans to recommend are lab-tested to confirm the dose, and independent purity certifications are checked. Oxidation values such as TOTOX are not part of the published method.
How good is omega-3 status in the population?
Studies that measured the Omega-3 Index in Germany found values below 8 % in more than 9 out of 10 participants: 99.6 % of 500 BASF employees (Rein 2020), 97.3 % of 446 women aged 40 to 60 (Gellert 2017) and 105 of 106 national-squad winter athletes (von Schacky 2014). 8 to 11 % is a target range proposed in research, not an official reference value.
Did Stiftung Warentest say omega-3 is useless?
Stiftung Warentest (test 06/2020) rated 20 omega-3 supplements as superfluous for protection against cardiovascular disease, because the benefit is not sufficiently proven. It did not measure people's omega-3 status; it referred to the German Nutrition Society's view that people are adequately supplied with plant-based omega-3 fatty acids.
Where can I find current omega-3 quality data?
In the free IFOS database at certifications.nutrasource.ca, which lists measured values for each batch, including EPA and DHA content, TOTOX, heavy metals, PCBs and dioxins. Manufacturers can also provide a certificate of analysis for your batch.
Your next step
How well supplied are you?
Questionnaires estimate, a blood test measures. Start with the free self-check and then decide whether a measurement is worth it for you.
Medical disclaimer
This article is for general information purposes only and does not replace medical advice. All health claims are based on EFSA-approved health claims and published studies. If you take medication, are pregnant or have raised blood lipid levels, talk to your GP before taking omega-3 supplements.
Sources
- Which?: Best omega 3 supplements (date tested May 2026, page checked July 2026) — which.co.uk (accessed 31.10.2026)
- Stiftung Warentest, press release "Mittel mit Omega-3-Fettsäuren: Überflüssig", 26.05.2020 — test.de
- Stiftung Warentest, test 06/2020 — test.de
- ÖKO-TEST 7/2012, overview — testberichte.de; ÖKO-TEST yearbook 2017, krill and algae oil capsules — oekotest.de
- Rein D et al. (2020), Nutrients 12(11):3267 — PMID 33113826
- Gellert S, Schuchardt JP, Hahn A (2017), Prostaglandins Leukot Essent Fatty Acids 117:54–59 — PMID 28237088; NutraIngredients report, 27.01.2017
- von Schacky C et al. (2014), Int J Sport Nutr Exerc Metab 24(5):559–564 — PMID 25203220
- Torrissen M et al. (2025), Lipids Health Dis 24:260 — PMID 40783537
- Harris WS, von Schacky C (2004), Prev Med 39(1):212–220 — PMID 15208005
- IFOS / Nutrasource certified products database — certifications.nutrasource.ca (accessed 31.10.2026)