What Happens If You Don't Take Fish Oil?

December 31, 2025 •

4 min read

According to the National Institutes of Health, many health organizations recommend at least 250 to 500 mg of combined EPA and DHA daily, which can be met by consuming fatty fish or supplements. When this essential fatty acid intake is insufficient, your body can begin to show a variety of signs, affecting everything from your skin to your cardiovascular health.

Quick Summary

Insufficient omega-3 intake can lead to a deficiency, resulting in symptoms like dry skin, hair changes, mood swings, joint pain, and fatigue. This deficiency may increase risks for heart disease, cognitive decline, and chronic inflammation.

Key Points

Skin and Hair Health: Omega-3 deficiency often manifests as dry, flaky skin, increased acne, and brittle hair due to a weakened moisture barrier.
Cognitive and Mood Function: Low levels can impair brain function, leading to poor concentration, memory issues, mood swings, and symptoms of depression and anxiety.
Cardiovascular Risks: Insufficient omega-3s can raise risk factors for heart disease by potentially increasing triglycerides and impacting blood pressure.
Inflammation and Joint Pain: Omega-3s have anti-inflammatory properties, and a deficiency can contribute to increased joint pain, stiffness, and susceptibility to inflammatory conditions.
Immune System Vulnerability: An omega-3 imbalance can affect immune function, potentially leading to increased vulnerability to infections and slower wound healing.
Eye Health Concerns: Low omega-3 intake is linked to dry eye syndrome and a higher risk of eye diseases due to insufficient moisture production.

Understanding Omega-3s: The Essential Fatty Acids

Fish oil is a prominent source of omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are crucial for cellular function and overall health. Unlike some other fats, the human body cannot produce these essential polyunsaturated fatty acids efficiently, meaning they must be obtained through diet or supplementation. A balanced intake of omega-3s is vital for maintaining a healthy inflammatory response, supporting brain and eye development, and promoting cardiovascular well-being. Without adequate intake, either from oily fish or supplements, the body's omega-3 levels can become depleted, leading to a host of physiological and cognitive changes.

The Immediate and Long-Term Effects of Low Omega-3 Intake

While the symptoms of an omega-3 deficiency can start subtly, they can escalate into more persistent health concerns if ignored. Initially, you might notice changes in your skin and hair, as omega-3s are key to maintaining moisture and integrity. Dry, irritated skin, increased acne, and brittle hair are common early indicators. Over time, however, a deficiency can impact more critical body systems, including the brain and joints. Cognitively, low omega-3 levels can affect memory, concentration, and mood, with links found to depression and anxiety. The anti-inflammatory properties of omega-3s are well-documented, and their absence can lead to increased joint pain and stiffness, particularly for individuals with inflammatory conditions like rheumatoid arthritis.

Impact on Cardiovascular and Immune Health

One of the most significant consequences of not taking fish oil is the potential impact on heart health. Omega-3s help regulate blood pressure, lower triglyceride levels, and reduce the risk of arterial plaque formation. Without them, these risk factors can become elevated, increasing the likelihood of cardiovascular disease. Furthermore, a depleted omega-3 status can affect the immune system. Omega-3s help manage the body's inflammatory response; a deficiency can weaken this system, potentially making you more susceptible to frequent colds and infections.

How an Omega-3 Deficiency Manifests

An omega-3 deficiency can reveal itself through a variety of observable symptoms. These signs are often non-specific and can be confused with other conditions, which is why paying attention to changes is important.

Skin Issues: The most common initial sign is dry, flaky, or rough skin. Some people may also experience more frequent acne breakouts or flare-ups of eczema.
Hair and Nail Changes: Hair may become dull, brittle, or thin, and nails can become soft or prone to peeling.
Mood and Cognitive Shifts: Individuals might experience increased fatigue, mood swings, difficulty concentrating, or symptoms of anxiety and depression.
Eye Dryness: Omega-3s contribute to tear production, so a deficiency can lead to dry, irritated, or itchy eyes.
Joint Discomfort: Increased joint pain, stiffness, and overall inflammation are classic signs of low omega-3 status.

Comparison of Omega-3 Sources: Dietary vs. Supplements

To address an omega-3 deficiency, one can increase their intake of fatty fish or opt for supplements. Both methods have their pros and cons.


Feature	Dietary Intake (Oily Fish)	Fish Oil Supplements
Form of Omega-3	Naturally occurring triglycerides (EPA and DHA) and vitamins A & D.	Concentrated triglycerides or ethyl esters (EPA and DHA).
Bioavailability	High, as the fatty acids are consumed with other fats in the fish.	High, especially when taken with a meal containing fat.
Risk of Contaminants	Potential for contaminants like mercury, especially in predatory fish, though most fish have low levels.	Reputable brands use purification processes to remove heavy metals and pollutants.
Convenience	Requires regular cooking and access to fresh, quality fish.	Easy to take daily as a capsule or liquid; ideal for those who don't eat fish.
Cost	Can be more expensive than supplements, especially for high-quality, fatty fish.	Generally affordable, but prices vary depending on concentration and brand.
Nutrient Synergy	Consumes omega-3s with other beneficial nutrients found naturally in fish.	Provides a more controlled, isolated dose of EPA and DHA.

The Importance of Consistency

Whether you choose to get your omega-3s from diet or supplements, consistency is key. The benefits of maintaining adequate levels build over time and are not instantaneous. If you stop your regular intake, your body will gradually deplete its stored omega-3s, and the symptoms of deficiency will likely return. For individuals with specific health concerns, such as high triglycerides or chronic inflammation, maintaining a steady intake is particularly important and should be discussed with a healthcare provider.

Vegetarian and Vegan Alternatives

For those who do not eat fish, other omega-3 sources are available. Plant-based sources like flaxseed, chia seeds, and walnuts contain alpha-linolenic acid (ALA), which the body can convert into EPA and DHA. However, this conversion rate is very low, making plant-based sources less efficient for raising EPA and DHA levels. A more direct and potent vegan option is algae oil, which provides a direct source of EPA and DHA, similar to fish oil, but is derived from the microalgae that fish consume.

Conclusion: Prioritizing Your Omega-3 Intake

Not taking fish oil or otherwise ensuring adequate omega-3 intake can have a cascade of negative effects on your health. From superficial issues like dry skin and hair to more serious, long-term concerns involving cardiovascular and cognitive health, the consequences of a deficiency are far-reaching. Fortunately, addressing this is straightforward, whether through a diet rich in fatty fish or through high-quality supplements. By being aware of the symptoms and taking proactive steps to maintain healthy omega-3 levels, you can support your overall well-being and protect against potential health risks. Consulting with a healthcare professional can help you determine the best approach for your individual needs. For more details on recommended intake and potential risks, the National Institutes of Health provides comprehensive guidance on omega-3 fatty acids.

Frequently Asked Questions

Symptoms of an omega-3 deficiency can include dry, irritated skin, brittle hair and nails, fatigue, mood swings, joint pain, and dry eyes. If you notice several of these signs, particularly if you don't regularly consume fatty fish, it may be a good idea to consider your omega-3 intake.

If you don't take fish oil supplements, you can still get omega-3s from a variety of food sources. Good sources of ALA (which your body can convert to EPA and DHA) include flaxseed, chia seeds, and walnuts. For direct EPA and DHA, consider algae-based supplements, which are vegan.

While plant-based sources like flaxseed contain ALA, the body's conversion rate of ALA to the more active EPA and DHA is very low. For optimal levels of EPA and DHA, especially for heart and brain health, a direct source like algae oil or fatty fish is often more effective.

The appearance of symptoms can vary widely depending on individual diet and physiology. Initial signs like skin dryness might appear relatively quickly, while more severe consequences like heart or cognitive issues develop over a longer period of chronic deficiency.

Stopping a fish oil supplement is generally safe, but any benefits you've been receiving will gradually fade as your body depletes its omega-3 stores. For individuals using fish oil to manage specific medical conditions, it's best to consult a healthcare provider before stopping.

If you consistently eat two or more servings of fatty fish like salmon, mackerel, or tuna per week, you may be getting enough omega-3s and not require supplementation. For those with higher needs or specific health conditions, a healthcare provider can advise on the appropriate intake level.

Yes, not taking fish oil can lead to deficiency symptoms like dry skin, fatigue, mood issues, and joint pain. For individuals with a poor diet, this can lead to an imbalance of inflammatory omega-6s over anti-inflammatory omega-3s, promoting chronic inflammation.