3 Reasons Your Fish Oil Is a Waste of Money

(The Concentration Rule)

Written by Lean Greens Crew | Evidence-Based

We’ve all heard the advice: “Eat more oily fish.”

So you did the sensible thing. You bought a tub of fish oil capsules. You took one every day. You waited for sharper focus, calmer joints, and that vague sense of “doing something good for yourself.”

And… nothing happened.

No difference. No noticeable change. Just the occasional fishy burp as a reminder.

If you’ve ever wondered “do omega 3 supplements actually work?”, you’re asking the right question.

The short answer is: Some do. Most don’t.

And the reason has very little to do with fish oil itself.

The One Big Thing Most Fish Oil Brands Don’t Tell You

We come back to this idea again and again because it explains so much confusion in the supplement world.

The Rule of 1.

When something should work but doesn’t, there’s usually one core issue quietly ruining the result.

With omega 3 supplements, that issue is concentration.

Not flavour. Not capsule size. Not how “premium” the label looks.

Most budget omega 3 products rely on volume, not potency.

You see a big number on the front:

“1000mg Fish Oil”

It sounds impressive.

But “fish oil” is just the carrier. The part that actually matters is what’s inside it.

Fish Oil vs Omega 3 (They’re Not the Same Thing)

This is where most people get misled.

Fish oil is a mixture of fats. Omega 3 refers specifically to two active fatty acids:

• EPA (Eicosapentaenoic Acid)
• DHA (Docosahexaenoic Acid)

These are the compounds associated with:

• Brain structure and signalling
• Visual and retinal integrity
• General heart and circulatory wellbeing
• Everyday cognitive clarity

When people talk about omega 3 benefits for brain fog, they’re talking about EPA and DHA, not “fish oil” in general.

Here’s the problem.

Most cheap supplements contain very little of them.

1. The “300mg” Trap

This is the most common reason people think omega 3 “doesn’t work.”

You buy a capsule labelled:

“High Strength 1000mg Fish Oil”

You assume you’re covered.

But when you flip the bottle over, the nutrition panel tells a different story.

Often you’ll see something like:

• EPA: 180mg
• DHA: 120mg

That’s 300mg total.

Do the maths

1000mg capsule 300mg active omega 3 700mg filler oil

That means 70% of what you’re swallowing is doing nothing.

Why this matters

Most evidence-based guidance suggests a minimum of 500mg EPA + DHA per day for meaningful everyday support.

At 300mg per capsule, you’d need:

• 2 capsules just to scrape the baseline
• 3–4 capsules to reach a more robust daily intake

Most people don’t do that.

They take one capsule, feel nothing, and quit.

The fix

Ignore the front label completely.

Always:

1. Turn the bottle around
2. Add EPA + DHA together
3. If it’s under 500mg per capsule, it’s weak

2. The Rancid Burp Problem (And Why It Happens)

Let’s talk about the thing everyone hates.

Fish oil burps.

If you’ve ever wondered “what causes fish oil burps?”, it’s not bad luck, and it’s not your digestion.

It’s usually oxidation.

Fish oil is fragile

Omega 3 fats are highly unstable. They degrade when exposed to:

• Heat
• Light
• Oxygen
• Time

This is why bulk “365-day supply” tubs are such a bad idea.

Once you open the bottle:

• Oxidation begins
• Oil slowly degrades
• Flavour and smell worsen

That unpleasant repeating taste is often a sign the oil is past its best.

Why this matters beyond taste

Oxidised oils:

• Are less effective
• Can irritate digestion
• Undermine the very reason you’re taking omega 3 in the first place

This is one reason people report:

“Fish oil makes my stomach feel off.”

It’s not the omega 3. It’s the quality.

The fix

Freshness matters more than quantity.

High-quality, high-concentration omega 3 should:

• Be virtually odourless
• Not repeat on you
• Come in sensible supply sizes you finish quickly

3. The Plant Omega 3 Confusion (ALA vs EPA/DHA)

This one catches a lot of well-meaning people out.

You decide to skip fish oil and get omega 3 from:

• Flaxseed
• Chia seeds
• Walnuts
• Fortified cereals

These are healthy foods.

But they contain ALA (Alpha-Linolenic Acid), not EPA or DHA.

Why this matters

Your body can convert ALA into EPA and DHA.

But the conversion rate is:

• Low
• Inefficient
• Highly individual

In many adults, less than 5% of ALA becomes usable EPA/DHA.

So while flaxseed is a nice addition to your diet, it’s not a reliable way to support:

• Brain structure
• Visual tissue
• Cognitive clarity

This is why people searching “omega 3 benefits for brain fog” often feel disappointed when relying on plant sources alone.

The fix

If you want the specific benefits linked to brain and eye health, you need:

• Marine omega 3 (fish or algae)
• Or a supplement that provides EPA and DHA directly

How Much EPA and DHA Do You Actually Need Per Day?

This is one of the most searched questions for a reason.

The answer depends on why you’re taking omega 3, but for general wellbeing:

• 500mg EPA + DHA per day is often considered a sensible baseline
• Many people choose 750–1000mg per day for more consistent support

The key point is this:

👉 It’s not about how much fish oil you take 👉 It’s about how much EPA + DHA you actually absorb

Two people can both take “1000mg fish oil” and get wildly different results.

Why People Think Omega 3 “Doesn’t Work”

When someone says:

“I tried omega 3 and didn’t notice anything”

What they usually mean is:

• The dose was too low
• The oil was diluted
• The product was oxidised
• Or all three

Omega 3 isn’t caffeine. It doesn’t give a buzz.

Its effects are subtle, structural, and cumulative.

But they only show up when the input is strong enough.

Supplements We Suggest (And Why)

This is an extension of concentration and freshness.

You could eat oily fish several times a week.

But in real life:

• It’s expensive
• It smells
• It’s inconsistent

So supplementation makes sense, if the supplement is actually doing the job.

At Lean Greens, we applied the Rule of 1 here too.

Maximum Potency. No filler.

Good Fats (Premium Omega 3)

Good Fats isn’t positioned as “cheap” or “high strength” in the marketing sense.

It’s designed to pass the Concentration Rule cleanly.

What makes it different

• 750mg EPA + DHA per capsule (That’s a 75% concentration, where many brands sit around 30%)

• One-capsule simplicity You don’t need a handful of pills to hit a meaningful intake.

• No fishy burps High-quality oil, sensible supply sizes, and proper handling.

• Brain-first formulation A strong DHA component to support everyday cognitive function and visual tissue.

• No weight-gain nonsense Despite common myths, omega 3 is about metabolic signalling, not calorie loading. Good Fats contains no carbs, no sugar, and fits easily into a balanced routine.

The real benefit

You stop guessing.

You know:

• How much EPA and DHA you’re getting
• Why you’re taking it
• And that you’re not paying for 70% filler oil

The Bottom Line

So… do omega 3 supplements work?

Yes. But only when they’re concentrated enough to matter.

If your fish oil:

• Contains under 500mg EPA + DHA
• Comes in massive year-long tubs
• Gives you fishy burps

It’s probably not doing much.

Stop paying for volume. Start paying attention to what’s actually inside the capsule.

👉 [Shop Good Fats Omega 3 & Check the Label Yourself]