What's the difference between EPA and DHA?

December 28, 2025 •

3 min read

According to the British Heart Foundation, the human body cannot produce essential omega-3 fatty acids, making dietary intake crucial. For this reason, it is vital to understand the functions of the two most important forms. So, what's the difference between EPA and DHA?

Quick Summary

EPA primarily reduces inflammation and supports cardiovascular health, while DHA is a key structural component for brain and eye function. Both are vital omega-3s, and their distinct roles are essential for optimal health.

Key Points

Distinct Roles: EPA primarily reduces inflammation and supports heart health, while DHA is a building block for brain and eye tissues.
Sources Matter: Both are in oily fish; DHA also comes from microalgae, suitable for vegetarians/vegans.
Brain Power: DHA enhances nerve communication and cognitive function, crucial for development.
Heart Protector: EPA's anti-inflammatory traits help lower triglycerides and reduce heart disease risk factors.
Ratio is Key: The optimal EPA:DHA ratio varies; higher EPA benefits mood/joints, higher DHA targets brain support.
Supplement Smarter: Check labels for EPA/DHA amounts and look for third-party purity testing.

Understanding Omega-3s: EPA and DHA

Omega-3 fatty acids are a type of polyunsaturated fat essential for human health, derived primarily from marine sources. While the body can convert alpha-linolenic acid (ALA) from plants into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), this conversion is inefficient, making direct dietary intake from fatty fish or supplements important. Despite often being grouped together, EPA and DHA have unique structures and functions within the body.

The Specialization of EPA

EPA is known for its powerful anti-inflammatory effects and benefits for heart health. It helps regulate cellular inflammation by interacting with pathways that produce inflammatory molecules.

Heart Health: EPA is well-documented for its cardiovascular benefits, including lowering triglyceride levels, reducing blood clot risk, and improving blood vessel function. High-dose EPA is even used in prescription medications for very high triglycerides.
Mood Support: Research indicates EPA can be effective in supporting mood and may be beneficial for symptoms of depression when used alongside conventional treatments.
Joint and Autoimmune Support: Due to its anti-inflammatory properties, EPA can help alleviate joint pain and stiffness associated with conditions like rheumatoid arthritis.

The Critical Role of DHA

DHA is crucial for brain and eye health due to its high concentration in these tissues. It supports cell membrane fluidity, aiding communication, especially in the nervous system. DHA is vital for brain and retina structure and growth, particularly during pregnancy and early childhood. It is associated with better cognitive function and visual health. For more detailed information on DHA's roles, see {Link: livemomentous.com https://www.livemomentous.com/blogs/all/epa-dha-ratio}.

EPA vs. DHA: A Comparison

Here is a comparison table outlining the key differences between EPA and DHA:


Feature	EPA (Eicosapentaenoic Acid)	DHA (Docosahexaenoic Acid)
Primary Function	Reduces inflammation and supports heart health	Structural component for brain and eye cells
Molecular Structure	20 carbon atoms, 5 double bonds	22 carbon atoms, 6 double bonds (longer and more flexible)
Brain Concentration	Lower levels, supports neuro-inflammation regulation	Abundant in cerebral cortex and retina
Mental Health	Stronger evidence for mood support and depression	Important for overall neural communication and function
Cardiovascular Health	Excellent for reducing triglycerides and inflammation	Also beneficial for blood flow and triglyceride reduction
Primary Source	Oily fish (salmon, sardines, mackerel)	Oily fish, microalgae

The best sources are marine, including fatty fish, and microalgae for DHA.

Importance of the EPA to DHA Ratio

A balanced intake of both EPA and DHA is beneficial, but specific goals may require adjusting the ratio. A higher EPA to DHA ratio may benefit heart health and inflammation, while a higher DHA to EPA ratio is often recommended for brain and eye health, especially during development. High-EPA formulas may be preferred for mood and inflammatory conditions.

Supplementation Considerations

When choosing a supplement, check labels for specific EPA and DHA amounts, as total fish oil weight can mislead. Choose brands with third-party purity testing. For more details on choosing supplements, see {Link: livemomentous.com https://www.livemomentous.com/blogs/all/epa-dha-ratio}.

Conclusion: Finding the Right Balance

EPA and DHA are vital omega-3 fatty acids with distinct roles. EPA focuses on inflammation and heart health, while DHA is crucial for brain and eye structure and function. Understanding their differences helps inform dietary and supplement choices, with optimal ratios potentially varying based on individual health goals. Consulting a healthcare professional is recommended. For further information on the specific roles of EPA and DHA, explore resources like {Link: Psychology Today https://www.psychologytoday.com/us/blog/in-the-zone/201204/what-are-the-real-differences-between-epa-and-dha}.

Frequently Asked Questions

Plant sources like flaxseed contain ALA, which the body can convert into EPA and DHA, but this conversion is very inefficient. Direct marine sources like fatty fish or microalgae oil are much more effective.

Neither is definitively 'better,' as they serve distinct but complementary functions. EPA is often preferred for heart health and inflammation, while DHA is critical for brain and eye structure. The best choice depends on your specific health goals.

EPA and DHA give rise to specialized lipid mediators called resolvins, which help resolve inflammation. EPA specifically competes with omega-6 fatty acids to produce less potent inflammatory compounds.

A higher EPA to DHA ratio, such as 2:1, is often recommended for maximizing anti-inflammatory and cardiovascular benefits, including reducing triglycerides and improving circulation.

DHA is crucial for the proper development of the fetal brain and eyes. Supplementation during pregnancy ensures adequate supply for the baby's rapid neural and visual growth.

Some studies suggest that EPA may be more effective than DHA in reducing symptoms of depression, particularly when used alongside antidepressant medication. Supplementing with a high-EPA formula may be beneficial for mood support.

Look for supplements from reputable brands that show proof of third-party testing for purity, such as NSF Certified for Sport. This ensures they are free of harmful contaminants like mercury.

For general health, a supplement containing both is beneficial, as they provide complementary benefits. However, for targeted health issues like heart health (more EPA) or cognitive function (more DHA), a specific ratio may be more effective.