Omega-3 in ADHD: Why I Frequently Recommend it in My Practice

There can be benefits of taking Omega-3 in ADHD — here's why, how much to take, and how to get it right.

Omega-3 in ADHD

As a medical doctor working with children and adults with ADHD, I get asked about supplements all the time, and I rarely recommend them. Most lack sufficient evidence, the effects are often overstated, or they distract from treatment that could actually help.

But Omega-3 is different. Multiple large-scale studies and meta-analyses now indicate that Omega-3 fatty acids, especially EPA and DHA, offer a small but significant benefit for ADHD symptoms like inattention and emotional lability.

They're not a miracle, but when taken consistently and in the right amounts, they can sometimes make a meaningful difference.

This article covers the research behind it, how much to take, how long it takes to work, and how to choose a quality supplement, or better yet, the right food. I’ll also share what I tell my own patients - and what I got wrong myself.

    The Key Points

• Omega-3 shows a small benefit on symptoms, supported by several research studies.
• In ADHD, EPA and DHA are what matter, not ALA from flax, walnuts, or chia.
• There are no official recommendations for Omega-3 dosages in ADHD, consult your doctor about your individual optimal amounts.
  
• My daily intake recommendations in ADHD are 900 mg for children 7 years or older, 1200 mg for adolescents, and up to 2000 mg for adults. Never exceed 3000 mg daily (from all sources).
• Supplement quality is critical as many cheap brands underdeliver or oxidize easily.
• Fatty fish 2-3x per week is ideal and provides more health benefits than supplements alone.

The Effects of Omega-3 in ADHD

The most important Omega-3 fatty acids for brain health are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These are the types of essential polyunsaturated fatty acids you find in abundance in fatty fish and algae. They are integral components of brain cell membranes, impacting fluidity, signaling, and overall function. 

ALA (alpha-linolenic acid) is technically another Omega-3 fatty acid, but it is rather a precursor to the important fatty acids EPA and DHA. ALA is mostly found in flaxseed and nuts.

Not getting enough Omega-3s (especially DHA and EPA) in early brain development can have negative effects consistent with dopaminergic hypoactivity of the prefrontal cortex. People with ADHD also tend to have lower Omega-3 levels, suggesting these fatty acids play an important role in ADHD.

Adequate Omega-3 intake, especially DHA, is linked to improved cognitive function, reduced risk of cognitive decline, and potentially even positive impacts on mental health conditions such as depression.

Supporting Research

A 2011 systematic review and meta-analysis of 10 randomized placebo-controlled trials found that Omega-3 fatty acid supplementation had a small but statistically significant effect in children with ADHD [Pubmed]

A 2016 meta-analysis of 10 research studies showed that Omega-3 fatty acids have positive effects on oppositional behavior and emotional lability in children vid ADHD, but only after doing a subgroup analysis. [NIH]

Another meta-analysis from 2023 reviewing 22 studies found, but only after a subgroup analysis, that Omega-3 fatty acids can significantly reduce the core symptoms (hyperactivity, impulsivity and inattention) of ADHD if taken for at least 4 months compared to placebo. [NCBI]

An interesting randomized placebo-controlled trial looked at 92 children and adolescents with ADHD and found that, in those with a deficiency of the Omega-3 fatty acid, EPA improved their attention and cognitive abilities the most when supplementing it for 12 weeks. [Nature]

The Effects To Expect

So, how effective are Omega-3 fatty acids for ADHD symptoms? According to several research papers, the effect is small, but real. After having closely reviewed the topic, my personal takeaway is that increasing intake of Omega-3 seems to improve inattention more so than hyperactivity and impulsivity.

The above research also indicated that the positive effects extend beyond ADHD core symptoms. In conclusion, Omega-3 polyunsaturated fatty acids may reduce hyperactivity, impulsivity, improve attention, reduce emotional lability and decrease oppositional behavior.

That being said, research also suggest that significant results only take place after an extended period of taking Omega-3 supplements daily. This makes sense from a physiological standpoint, as changes in cell membrane fatty acid composition reflect long-term dietary habits. As such, it likely takes at least 3-4 months for Omega-3 supplementation to show any potential benefits.

Fortunately, Omega-3 is generally well-tolerated and has no reported severe side effects. The most frequent side effect in one of the aforementioned meta-analyses was gastrointestinal discomfort and an incidental nosebleed.

How Much Omega-3 You Need

There are no official expert recommendations for dosages of Omega-3, except for ALA. Research studies on EPA and DHA have been conducted with a wide variety of doses. 

For those with ADHD, I recommend the total daily intake of Omega-3 to be 900 mg of EPA and DHA for children 7 years and older, 1200 mg for adolescents, and up to 2000 mg for adults. Some research suggests a higher ratio of EPA compared to DHA may be favorable for reducing ADHD symptoms.

These numbers translate into eating fatty fish approximately 3 times a week. If that's not achievable, then Omega-3 supplementation should be considered as a part of your daily morning routine. 

The FDA recommends that your daily intake of omega-3 fatty acids (EPA and DHA combined) from all sources should not exceed 3000 mg, as it may potentially cause issues like blood thinning.

The Best Way To Get Omega-3

Now that we know how much Omega-3 helps and in what doses, let’s talk about how to actually get it into your (or your child’s) diet.

Why Nuts Aren't Enough

Short story - For the past three years, I thought that I was getting enough Omega-3. With every breakfast, I'd consume around 20-40g of walnuts and take 900 mg of EPA+DHA in the form of a supplement. When I recently had my Omega-3 and Omega-6 levels tested, my EPA and DHA levels were extremely low.

While nuts and seeds can have other health benefits, relying on them for EPA and DHA is not a great strategy, because the conversion rate of ALA to EPA and DHA in the body is very low (5-10%).

Importance of Quality Supplements

This ties into my next important point. Despite supplementing Omega-3, the blood test showed that I had very low levels of EPA and DHA, well beyond what can be considered healthy or normal. Walnuts or not, I was supplementing these fatty acids for almost three years. Turns out the capsules I was taking were cheap and devoid of any Omega-3, and I learned my lesson.

The quality of Omega-3 supplements varies significantly due to factors like sourcing, processing, and potential oxidation. This variability can affect their efficacy and safety. 

Remember to look for a higher-quality brand with the correct certifications, or simply stick to eating a sufficient amount of fatty fish. In case you decide to rely on supplements, make sure to store it in a cool and dark place, as Omega-3 breaks down when exposed to heat and light. Avoid gummies and candy forms of Omega-3, as they often contain insufficient EPA and DHA and are prone to oxidation. 

Fatty Fish Still Wins

Eating fish comes with more health benefits than getting Omega-3 purely as a supplement, especially in terms of cardiovascular health. You want to look for fatty cold-water fish like salmon, mackerel, herring and sardines. Eel is another very Omega-3-rich option. Tuna is a great option if you get the fattier parts, but the lean cuts and canned tuna are lower in Omega-3.

Still, it's better than nothing. Even fish sticks contain some amount of Omega-3 fatty acids. This can be kept in mind, as many children would rather eat fish a couple of times a week rather than try to swallow fish oil or large capsules. In our home, we have 'Fish Fridays', 'Tuna Tuesdays' and 'Salmon Sundays'. While silly sounding, both kids and adults can get sold with a proper catchphrase.

A Healthy Addition To Treatment

Now you know why I frequently recommend Omega-3 (specifically EPA and DHA) in my practice, especially from food sources. It can provide a significant benefit to overall health and to specific difficulties in ADHD, while also having a great safety profile with low risks of side effects.

But it is not a replacement for proper ADHD pharmacotherapy in those who need it. If you’re curious about which ADHD medication could be suitable for you, WhatMedicine.Org offers a simple quiz to help you get a better sense of the most common options.

The is not medical advice but may be a helpful first step before consulting your psychiatrist. 

Cover image by Freepik

Author: J. Martin, M.D.
Last update: August 10, 2025

Disclaimer: The information provided is intended for general informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider, such as a physician, before starting any new treatment or making changes to your existing treatment plan. Individual responses to treatment may vary, and a healthcare professional can provide personalized guidance based on your specific needs and circumstances. If you are experiencing severe or persistent symptoms of disease or mental illness, seek immediate medical attention.