TG type: Closer to the natural form found in fish.
EE type: Artificially esterified to increase the purity of Omega-3.
Let's compare them in detail:
Key Differences Comparison Table
Characteristics | TG type (triglyceride type) | EE type (ethyl ester type) |
Natural Form | Yes, fish oil is the original natural form extracted from fish. | No, it is made from TG-type fish oil through a transesterification process. |
Chemical Structure | Omega-3 fatty acids (such as EPA and DHA) are naturally linked to a glycerol backbone. | Omega-3 fatty acids detach from the glycerol backbone and combine with ethanol (alcohol) to form ethyl esters. |
Omega-3 Concentration | Low concentration. Typically around 30%, and rarely exceeding 60% for high-concentration TG-type fish oil. | The ethyl ester content is very high. This process allows for easy purification, and most high-concentration fish oils on the market, with concentrations of 70%, 80%, or even 90% or more, are of the EE type. |
Absorption Efficiency | Theoretically, it has advantages. Because it is in its natural form, the body (intestines) can directly recognize and absorb it. | It requires an extra step of metabolism. The body needs to "cut" it out using liver enzymes before resynthesizing it back into its natural triglyceride form for utilization. However, with long-term use, the difference in absorption between the two is not significant. |
Bioavailability | Traditional views held that the TG form was more potent. However, modern research, especially with long-term use, shows that there is no significant clinical difference in the final bioavailability of the two in the body. | |
Stability | Good. Its chemical structure is stable and it is not easily oxidized. | Slightly worse. Ethyl ester bonds are relatively fragile and more susceptible to oxidative rancidity. |
Price | It is usually cheaper (referring to the standard concentration). High-concentration TG fish oil is expensive due to its complex processing. | High-concentration EE-type fish oil offers better value for money, providing more EPA and DHA for the same price. |
Common Products | Most fish oils are regular fish oils, food-grade fish oils, or children's fish oils. | Almost all high-concentration or prescription-grade fish oils (such as Vascepa and Lovaza). |
Detailed Explanation and How to Choose
1. TG Type Fish Oil
Advantages:
Natural Form: The body is more familiar with it, resulting in a more direct absorption pathway.
Better Stability: Less prone to oxidation, ensuring better quality within the shelf life.
Taste/Stomach Comfort: Generally considered less irritating to the stomach, with less fishy odor reflux.
Disadvantages:
Low Concentration: To obtain a specific dose of EPA and DHA, you may need to take more capsules.
2. EE Type Fish Oil
Advantages:
High Concentration: This is its biggest advantage. If you need a high dose of Omega-3 supplementation (e.g., to lower triglycerides), the EE type allows you to achieve your goal with fewer capsules, which is very convenient.
High Cost-Effectiveness: For the same EPA/DHA content, high-concentration EE fish oil is generally much cheaper than high-concentration TG fish oil.
Disadvantages:
Absorption Requires Conversion: While the long-term absorption rate is similar to TG, absorption may be slightly slower with a single dose.
Slightly Less Stable: Requires higher standards for production and storage, necessitating the addition of sufficient antioxidants (such as Vitamin E).
Stomach Discomfort: May cause stomach upset or a fishy odor for a small number of sensitive individuals.
Summary and Purchase Recommendations:Which one should I choose?
For Those Seeking High Dosage and Cost-Effectiveness:
If you need a therapeutic-grade high dose of Omega-3 (e.g., your doctor recommends supplementing with more than 1000mg of EPA+DHA daily), or you want to ingest the most effective ingredients with the fewest capsules, then EE fish oil is an excellent choice.
For Those Seeking Natural and Daily Health Maintenance:
If you are using it for daily health maintenance, have low dosage requirements (around 500mg daily), or have a sensitive stomach, then TG fish oil may be more suitable. Children's fish oil is also typically in the TG form.
Focus on absorption and stability:
Theoretically, the TG form is slightly better. However, for long-term users, the final effects are similar. If you are very particular about the "natural" concept, choose the TG form.
The most important tip:
Read the label, not just the type! Regardless of the type, the most crucial thing is to check the specific EPA and DHA content on the product label (not the total fish oil content). A TG fish oil with a total content of 1000mg but only 300mg of EPA+DHA is far inferior to an EE fish oil with a total content of 500mg but 400mg of EPA+DHA.
Choose a reputable brand: Larger brands do a better job in purity and oxidation control, which is especially important for EE fish oil.
Take with meals: Regardless of the type of fish oil, taking it with meals (especially fatty meals) greatly improves absorption and reduces stomach discomfort.