Reviewed by Jessie, BSc Biomedical Science (IMU Malaysia) · Formulation Lead, Purest Kids
Most parents who look carefully at omega-3 supplements focus on the DHA milligram count. That is the right instinct. But there is a second variable that affects how much DHA your child actually absorbs: the molecular form in which it is delivered. Two products with identical DHA figures on the label can produce meaningfully different results in the body.
The two main molecular forms
Omega-3 supplements come in two primary molecular forms: triglyceride (TG) and ethyl ester (EE).
Triglyceride is the natural form. DHA and EPA occur as triglycerides in fish tissue and in algae. When you eat fatty fish, you are consuming omega-3 in triglyceride form — exactly as it exists in nature.
Ethyl ester is a processed form. Fish oil is often concentrated and purified using a process that converts triglycerides into ethyl esters. This makes it easier to remove impurities and increase the concentration of DHA and EPA, but it changes the molecular structure of the fat in a way that affects how the body processes it.
What the research shows on absorption
Multiple studies have compared the bioavailability of triglyceride and ethyl ester omega-3. The consistent finding is that triglyceride form omega-3 is better absorbed.
A key study published in Lipids (Dyerberg et al., 2010) found that triglyceride form omega-3 was absorbed approximately 73% more effectively than ethyl ester form under fasted conditions. Under fed conditions (taken with a fat-containing meal), the gap narrows, but triglyceride form still demonstrates better bioavailability in most studies.
A systematic review in the European Journal of Clinical Nutrition (Schuchardt & Hahn, 2013) confirmed that natural triglyceride and re-esterified triglyceride forms of omega-3 show superior bioavailability compared to ethyl esters. For practical purposes, if two supplements list the same DHA dose but one is TG form and one is EE form, the TG product is likely delivering meaningfully more DHA to the tissues that need it.
Why ethyl ester became so common
Ethyl ester production is cheaper and easier to scale than maintaining the natural triglyceride form through the concentration process. Many high-volume fish oil manufacturers use EE form because the economics favour it, not because it is the better choice for the consumer. Some manufacturers convert EE back to TG after concentration — a process called re-esterification — but this is more expensive and less common in mass-market products.
How to identify the form on a label
Labels do not always make the molecular form obvious. Look for language like "natural triglyceride form," "TG form," or "re-esterified triglyceride." If the label does not mention the form at all, it is more likely to be ethyl ester.
Algae oil products, including Omega-3 Mango Burstlets, use algae oil in triglyceride form. Because algae oil is not subject to the same concentration process that converts fish oil to ethyl esters, the triglyceride structure is preserved from source to product.
The practical implication
Two supplements with the same stated DHA dose are not equivalent if one is in triglyceride form and one is in ethyl ester form. If you are carefully evaluating DHA content per serve — which is the right thing to do — it is worth also checking the molecular form. For a full guide to reading supplement labels, see How to Read a Children's Supplement Label.
Frequently asked questions
Does it matter whether I take omega-3 with food?
Yes, particularly for ethyl ester form. Research shows that taking omega-3 with a fat-containing meal improves absorption significantly, especially for EE form products. For triglyceride form products, absorption is better across the board, but a fat-containing meal still helps. Taking Omega-3 Mango Burstlets with breakfast — particularly with eggs, full-fat dairy, or avocado — is ideal.
What is re-esterified triglyceride (rTG) form?
Re-esterified triglyceride is fish oil that has been concentrated (converting it to ethyl ester) and then chemically converted back to triglyceride form. Studies show its bioavailability is similar to natural triglyceride form and significantly better than ethyl ester. It is more expensive to produce, which is why it is less common in mass-market products.
Is the difference in absorption significant enough to matter in practice?
For a child taking a supplement with a borderline DHA dose (40 to 80mg), the difference between TG and EE form may determine whether any meaningful DHA reaches the brain at all. For a supplement delivering 450mg DHA in TG form, the high dose combined with good absorption makes a strong case for actual efficacy. Both variables — dose and form — point in the right direction.
Reviewed by Sonia, BSc Nutrition & Metabolism (University of Sydney, Distinction), Advanced Diploma in Sports Nutrition (Institute of Performance Nutrition).
See Omega-3 Mango Burstlets — TG form, 450mg DHA →
References
- Dyerberg J, et al. "Bioavailability of marine n-3 fatty acid formulations." Prostaglandins, Leukotrienes and Essential Fatty Acids, 2010. PubMed
- West AL, et al. "Pharmacokinetics of Supplemental Omega-3 Fatty Acids Esterified in Monoglycerides, Ethyl Esters, or Triglycerides in Adults in a Randomized Crossover Trial." The Journal of Nutrition, 2021. PMC
- National Institutes of Health. "Omega-3 Fatty Acids — Health Professional Fact Sheet." Office of Dietary Supplements. NIH