Omega-3 for Athletes: Reading EPA and DHA per Capsule – 18/12 or High-Strength?

Hardly any supplement sits in the kitchen cupboard as naturally as omega-3 capsules. And hardly any is misread as often. "1,000 mg fish oil" on the pack sounds like a lot – but what matters are two fatty acids inside it, EPA and DHA, and their amount can differ several times over between two products.

In this article I explain how much EPA and DHA you need, what omega-3 demonstrably does and doesn't do, how to recognise good fish oil and how to read labels properly. At the end I compare our two fish oil products. How to check supplements in general is covered in my guide How to evaluate supplements.

ALA, EPA and DHA: which omega-3 fatty acids count

The body can make EPA and DHA from ALA, but only to a limited extent – for DHA usually in the low single-digit percentage range or below. So if you hardly eat fish, you won't cover your EPA and DHA needs with flaxseed oil and walnuts, however healthy they are otherwise.

How much EPA and DHA do you need?

The European Food Safety Authority (EFSA) names 250 mg of EPA and DHA per day as an adequate intake for adults. The German Nutrition Society recommends eating fish once or twice a week, once of it oily sea fish. There is no officially higher requirement for athletes.

One portion of salmon or herring a week therefore already exceeds the EFSA guideline on a weekly average. If you eat oily fish regularly, you don't need capsules.

What omega-3 demonstrably does – and what it doesn't

The EU has approved several health claims for EPA and DHA, each with a minimum amount:

There is no approved claim for performance, strength, muscle growth, joints or recovery. Individual studies show small effects on muscle soreness after unaccustomed exercise, but the results are inconsistent. My conclusion for athletes: omega-3 is part of your basic nutrient supply, not a performance supplement.

Reading the label properly

Fish oil is not the same as omega-3

Many packs say "1,000 mg fish oil" in large print. That's the amount of oil, not the active ingredient. A standard oil contains about 30 percent EPA and DHA, a concentrate 60 percent or more. Three lines in the nutrition table are what matter:

• EPA per daily dose
• DHA per daily dose
• Total omega-3 fatty acids (may include other omega-3 fatty acids)

What "18/12" and "35/25" mean

The two numbers give the share of EPA and DHA in the oil as a percentage:

• 18/12: 18 percent EPA, 12 percent DHA – an untreated standard fish oil.
• 35/25: 35 percent EPA, 25 percent DHA – a concentrate with twice as much active ingredient per gram of oil.

With the same capsule size, the concentrate therefore contains twice as much EPA and DHA. For you that means fewer capsules for the same dose.

Triglyceride or ethyl ester

In nature, fish oil occurs as a triglyceride. During concentration it is often converted into an ethyl ester and sometimes converted back into a triglyceride (re-esterified triglyceride). Both forms are absorbed; triglycerides perform slightly better in studies when taken without a fatty meal. The practical advice is simpler than the chemistry: take omega-3 with a meal. Then the difference is small.

Both Syrax fish oils are triglycerides.

Quality: heavy metals, oxidation, origin

Heavy metals

Fish can accumulate mercury and other contaminants. In the EU, maximum levels apply to food supplements, including 0.10 mg of mercury per kilogram. For our Omega 3 18/12 there is a lab report from December 2025 (batch V0046BOD): lead, cadmium and mercury below the EU maximum levels, microbiology without objection. For Omega 3 Max there is a manufacturer certificate, which we link on the product page.

Oxidation: the underrated quality factor

Omega-3 fatty acids are sensitive to oxygen, light and heat. Oxidised fish oil smells rancid, tastes unpleasant and has lost part of its value. The industry organisation GOED has defined limits for this, for example for the peroxide value and the so-called TOTOX value.

To be honest: our current reports test heavy metals and microbiology, but no oxidation values. That's the case with many suppliers, but with fish oil in particular I'd like to see these values – we have requested them for the next batches. Until then, a simple test helps: cut a capsule open and smell it. A light sea smell is normal, a rancid smell is not.

Origin and capsule shell

According to the label, Omega 3 Max comes from wild-caught fish. Both Syrax products use halal-compliant bovine gelatine for the capsule shell and natural vitamin E as an antioxidant. If you want to avoid fish or animal gelatine, you need an algae oil in a plant-based capsule.

Syrax Omega 3 18/12 and Omega 3 Max compared

All values according to the label, prices from the shop (October 2026).

• Omega 3 18/12€0.75
• Omega 3 Max 35/25€0.39

›Show data as table

Category	Price per gram of EPA + DHA
Omega 3 18/12	€0.75
Omega 3 Max 35/25	€0.39

My assessment

Omega 3 Max is the better choice for most people. Twice as much EPA and DHA per capsule, almost the same price per pack – per gram of active ingredient it costs only just over half. If you hardly eat fish and go by the approved heart claim, you need 250 mg of EPA + DHA a day: one Max capsule with 600 mg delivers more than enough, and the pack then lasts 120 days.

Omega 3 18/12 suits a gentle basic intake. One capsule delivers 300 mg of EPA + DHA – right in the range of the EFSA guideline. If you deliberately want a low dose or also eat fish now and then, take one capsule a day and the pack lasts four months. The vitamin E it contains (24 mg per two capsules) protects the oil from oxidation and stays below the BfR proposal of 30 mg.

Honest about the numbers: the label's daily dose of two Max capsules delivers 1,200 mg of EPA + DHA. That's not quite enough for the triglyceride claim (2 g), and several times what the heart claim requires. More is not automatically better here – choose the dose based on how much fish you eat.

Who needs which dose?

If you want to know exactly, you can have your omega-3 index measured in the blood. It shows the share of EPA and DHA in red blood cells; values around 8 percent are considered favourable. The test is usually self-paid, but it can help you adjust the dose precisely.

Tips for taking it

• Take with a meal containing some fat – that improves absorption and reduces burping.
• Store cool and dark, ideally in the fridge after opening.
• Fishy burps? Take the capsule with food rather than on an empty stomach, and split the dose between morning and evening.
• Throw away capsules that smell rancid.
• Combine with vitamin D? No problem – both are fat-soluble and are easily taken together with a meal. More on vitamin D dosing in Dosing vitamin D correctly.

Conclusion: fewer capsules, more active ingredient

Omega-3 is not a performance booster, but it is a sensible building block for anyone who eats little fish. When buying capsules, don't look at "1,000 mg fish oil" but at EPA and DHA per daily dose – and compare the price per gram of these two fatty acids. You'll quickly see that a concentrate like our Omega 3 Max is often the more efficient choice, while one 18/12 capsule is perfectly sufficient for a basic intake.

How to check other supplements using the same pattern is explained in How to evaluate supplements. Next week is about a topic that affects everyone, especially in winter: Dosing vitamin D correctly.

Sources: EFSA: Scientific Opinion on the Tolerable Upper Intake Level of EPA, DHA and DPA (2012) · EU Register of nutrition and health claims · Regulation (EU) 2023/915 on maximum levels for contaminants · GOED Voluntary Monograph (quality standard for omega-3 oils) · Labels and lab reports of the Syrax products (as of October 2026)