What's the Difference Between Phospholipid Omega-3 and Triglyceride?

Not all omega-3 supplements are created equal. The form in which EPA and DHA are delivered, phospholipid or triglyceride, can influence absorption, effectiveness and tolerability. Understanding these differences can help you choose the right omega-3 for your fertility goals, based on your individual needs rather than assuming one format is always better than another.

The two main forms of omega-3

Triglyceride omega-3 (TG form) is the natural form found in fish tissue and is most commonly used in fish oil supplements. The omega-3 fatty acids EPA and DHA are attached to a glycerol backbone in sets of three.

Phospholipid omega-3 (PL form) is the natural form found in krill, herring roe (caviar) and some marine sources. EPA and DHA are attached to phospholipids, the same type of fat molecule that makes up your cell membranes.¹

Key difference #1: Absorption and bioavailability

Phospholipid omega-3s are water-dispersible, meaning they mix more easily in the watery environment of your digestive system and rely less on bile salts than triglyceride oils. This can be helpful for some people, particularly where digestion, absorption or inflammation are part of the picture.²

Research findings:

• A study comparing phospholipid vs triglyceride omega-3 found that phospholipid forms resulted in significantly higher blood levels of EPA and DHA at equivalent doses.²
• Phospholipid omega-3s may be better incorporated into cell membranes, particularly in the brain, liver and reproductive tissues.³
• The enhanced bioavailability may help some people achieve therapeutic omega-3 levels at lower absolute doses when using phospholipid forms.

Key difference #2: Anti-inflammatory and metabolic effects

Experimental research directly comparing phospholipid vs triglyceride omega-3 shows that even when total EPA and DHA content is matched, phospholipid forms can produce stronger anti-inflammatory and metabolic effects in inflammatory models.⁴

Key findings from comparative studies:

• Stronger anti-inflammatory effects: Phospholipid omega-3 produced greater reductions in inflammatory markers and better modulation of immune responses.
• Better metabolic health: Improved insulin sensitivity, reduced liver fat and better glucose regulation with phospholipid forms.
• Enhanced SPM production: Phospholipid omega-3 generates higher levels of DHA-derived specialised pro-resolving mediators, the compounds that actively resolve inflammation.⁴

For fertility, these anti-inflammatory effects are particularly relevant given the link between chronic inflammation and poorer reproductive outcomes, especially in conditions where inflammation is a known driver such as endometriosis, PCOS and during IVF treatment cycles.⁵

However, this does not mean triglyceride omega-3 is ineffective. High-quality triglyceride fish oils remain a robust, evidence-based option for general reproductive health, membrane support and DHA intake, particularly for those without inflammatory drivers.

Key difference #3: Digestive tolerability

Many people struggle with fishy burps, reflux or digestive upset from fish oil capsules, while others tolerate them well. Phospholipid omega-3s are often better tolerated by sensitive individuals:

• Better emulsification: Phospholipids naturally form micelles in water, making them easier to digest.
• Less reflux: Because they can be absorbed more efficiently in the upper small intestine, there may be less chance of rancid oil reflux.
• Smaller serving size needed: Enhanced bioavailability can mean fewer large capsules to swallow for some people.

Clinical evidence: 25% inflammation reduction

Recent clinical research on a herring roe (caviar) phospholipid omega-3 demonstrated a 25% reduction in the Systemic Immune-Inflammation Index (SII) over 52 weeks in over 500 participants.⁶

This validates that phospholipid-rich herring caviar oil can meaningfully reduce systemic inflammation at clinically tested doses. SII is independently associated with IVF outcomes and miscarriage risk, making this particularly relevant for fertility.⁷

This level of inflammation reduction is most relevant for people with inflammatory fertility challenges, rather than those simply aiming to maintain baseline omega-3 sufficiency.

What about the other supplement forms on the label?

Some omega-3 supplements use different chemical forms, which can affect how well your body absorbs them:

• Ethyl ester (EE)
  This is a semi-synthetic form made during the oil purification process.
  It’s less easily absorbed by the body compared with natural forms.
• Re-esterified triglyceride (rTG)
  This starts as ethyl esters but is then converted back to a form closer to what’s found in fish.
  Better absorbed than EE, but still not as efficient as phospholipid omega-3.

Which form is best for fertility?

Both forms of omega-3 have a place in fertility care. The key is matching the format to the individual, including your health context, inflammatory burden and what you are trying to optimise.

A strong starting point: Vital DHA (triglyceride omega-3)

For many people, a high-quality triglyceride omega-3 is an excellent starting point for foundational fertility nutrition, particularly when there are no known inflammatory drivers. Vital DHA provides a DHA dominant profile with supportive EPA, alongside zinc which contributes to normal fertility and reproduction.

Vital DHA daily intake

2 capsules per day provide:

• Fish oil, derived from fish, of which 50% DHA (Docosahexaenoic acid) and 10% Eicosapentaenoic Acid (EPA): 1072mg
• Zinc: 3mg (30 NRV)

When to consider upgrading: Ultra Omega (phospholipid omega-3)

For those with inflammatory fertility challenges, including endometriosis, PCOS, or those preparing for IVF, phospholipid omega-3 can be a logical next step. The evidence suggests phospholipid forms may offer enhanced tissue delivery and stronger anti-inflammatory signalling in relevant contexts.⁴

It sources its EPA and DHA from herring-caviar oil, delivering these fatty acids in the phospholipid form, the type most easily absorbed and best integrated into cell membranes. 

For people focused on fertility and overall reproductive health, its superior bioavailability and gentle digestibility make it a convenient, effective way to ensure high-quality omega-3 intake.

Choosing your omega-3

If you're unsure where to start, we offer free 20 minute 1:1 consultations with our in-house team of fertility nutritionists. They can help understand your starting point and recommend supplements to suit your journey. Book yours here.

While omega-3 triglyceride fish oils can provide omega-3 benefits, phospholipid forms like herring caviar oil may offer a more targeted option for those with inflammation, metabolic disruption or absorption challenges.

For fertility support, where you are aiming to optimise egg quality, reduce inflammation and improve reproductive outcomes, it can be helpful to start with a strong foundational omega-3 such as Vital DHA and then step up to a phospholipid option if your clinical picture suggests you would benefit from more targeted support.

References

1. Kohler A et al. Bioavailability of fatty acids from krill oil, krill meal and fish oil. Lipids Health Dis.
2. Schoen C et al. Enhanced absorption of omega-3 fatty acids from a novel krill oil-derived phospholipid formulation compared to fish oil ethyl esters: A randomized, two-way crossover pharmacokinetic study. Science Direct.
3. Sugasini D et al. Enrichment of brain docosahexaenoic acid from dietary lysophosphatidylcholine. J Nutr Biochem.
4. Rossmeisl M et al. Metabolic effects of n-3 PUFA as phospholipids are superior to triglycerides. PLoS One.
5. Li X et al. Systemic inflammation and IVF outcomes. Reprod Biomed Online.
   
6. New positive data showing anti-inflammatory effects of HRO350 in the HeROPA trial. Arctic Bioscience.
7. Sun K et al. Association between systemic immune-inflammation index and miscarriage: A case-control study. PubMed.
8. Dyerberg J et al. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids.