Omega-3 fatty acids are among the most widely used ingredients in dietary supplements. Fish oil supplements and krill oil supplements are two popular sources of omega-3, but they are not identical. They differ in their natural sources, omega-3 composition, lipid structure, dosage, appearance, and manufacturing considerations.

For supplement brands, understanding the differences between fish oil and krill oil is important when developing a new omega-3 product, selecting raw materials, and determining the appropriate dosage form.

What Is Fish Oil?

Fish oil is an oil derived primarily from oily fish such as anchovies, sardines, mackerel, and other marine fish. It is naturally rich in the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

Fish oil is available in different concentrations and forms. Depending on the raw material and purification process, fish oil can be supplied as:

• Natural triglyceride (TG)

• Re-esterified triglyceride (rTG)

• Ethyl ester (EE)

• Concentrated EPA or DHA oils

Fish oil is widely used in softgel capsules because it can provide a relatively high amount of EPA and DHA in a compact dosage form.

What Is Krill Oil?

Krill oil is extracted from small marine crustaceans called Antarctic krill. It naturally contains EPA and DHA, but its lipid composition differs from conventional fish oil.

One important characteristic of krill oil is that a significant proportion of its omega-3 fatty acids is naturally associated with phospholipids. Krill oil also naturally contains astaxanthin, a carotenoid that contributes to its characteristic red-orange color.

Because of these characteristics, krill oil is often positioned as a premium alternative to conventional fish oil in the dietary supplement market.

Fish Oil vs. Krill Oil: Key Differences

1. Source: Fish vs. Krill

The most obvious difference is the source.

Fish oil is obtained from marine fish, commonly small oily fish. The raw material is processed and purified to obtain an oil suitable for food or dietary supplement applications.

Krill oil is obtained from krill, particularly Antarctic krill. Because krill is a marine crustacean, sourcing and supply considerations are different from those associated with fish oil.

For supplement manufacturers, raw material traceability, sustainability documentation, specifications, and supplier qualification should all be considered during product development.

2. EPA and DHA Content

Both fish oil and krill oil naturally provide EPA and DHA.

However, the concentration can be significantly different depending on the raw material.

Highly concentrated fish oils can provide substantial amounts of EPA and/or DHA per gram of oil. This makes fish oil particularly suitable for products where the target is a relatively high EPA or DHA content.

Krill oil generally contains a lower percentage of EPA and DHA compared with highly concentrated fish oil. Therefore, the amount of krill oil required to achieve a specific omega-3 claim needs to be carefully calculated.

For a new product, supplement brands should evaluate the actual EPA and DHA content, rather than comparing fish oil and krill oil simply by the total oil weight.

3. Phospholipids

One of the major differences between fish oil and krill oil is their lipid structure.

Many krill oil products contain omega-3 fatty acids associated with phospholipids, while conventional fish oils may contain omega-3 in triglyceride, re-esterified triglyceride, or ethyl ester forms.

This structural difference is an important marketing and formulation characteristic of krill oil.

However, product developers should distinguish between the chemical form of omega-3 and claims about physiological effects. The benefits of a finished product depend on multiple factors, including dosage, formulation, and overall diet.

4. Natural Astaxanthin in Krill Oil

Krill oil naturally contains astaxanthin, which gives the oil its characteristic reddish-orange color.

This creates a clear visual difference between many krill oil and fish oil products.

For supplement brands, natural astaxanthin can also provide an additional product differentiation point. However, the actual astaxanthin concentration depends on the raw material and manufacturing process, so it should be verified through the supplier's specification and analytical testing.

5. Dosage and Product Formulation

Fish oil is highly versatile for supplement formulation. It can be used in:

• Softgel capsules

• Liquid supplements

• Emulsified products

• Powdered omega-3 ingredients

• Functional food applications

Krill oil is most commonly formulated into softgel capsules because of its oil-based nature and relatively high cost.

For a softgel manufacturer, the formulation must consider more than just the active ingredient. Factors such as oil viscosity, fill weight, gelatin or alternative shell material, antioxidants, capsule size, and stability can influence the finished product.

6. Oxidation and Stability

Omega-3 oils are susceptible to oxidation, so oxidation control is an important consideration for both fish oil and krill oil products.

Manufacturers commonly monitor parameters such as:

• Peroxide Value (PV)

• p-Anisidine Value (p-AV)

• TOTOX

• EPA and DHA content

• Heavy metals

• Dioxins and PCBs, where applicable

• Microbiological parameters

Packaging also plays an important role. Appropriate packaging, oxygen control, storage conditions, and antioxidant systems can help maintain product quality throughout its shelf life.

For both fish oil and krill oil softgels, stability testing should be considered when establishing the finished product's shelf life.

7. Cost Difference

In general, krill oil is more expensive than conventional fish oil.

The cost difference can result from raw material availability, processing, extraction, concentration, sourcing requirements, and the natural composition of krill oil.

Fish oil also offers a wide range of specifications, from standard fish oil to highly concentrated EPA/DHA materials. This gives supplement brands more flexibility when developing products at different price points.

For a mass-market omega-3 supplement, fish oil may provide a more economical formulation. For premium products, krill oil can provide a differentiated positioning.

Fish Oil or Krill Oil: Which Should Supplement Brands Choose?

There is no single answer for every product. The appropriate ingredient depends on the target market, dosage, product positioning, formulation requirements, and cost target.

Fish oil may be suitable when:

• A higher EPA/DHA concentration is required

• Cost competitiveness is important

• The product targets the mainstream omega-3 market

• Multiple EPA/DHA ratios are required

• A larger range of raw material specifications is needed

Krill oil may be suitable when:

• The product is positioned as a premium omega-3 supplement

• Phospholipid-associated omega-3 is an important product feature

• Natural astaxanthin is desirable

• The brand wants to differentiate from conventional fish oil

• A premium softgel product is being developed

Fish Oil vs. Krill Oil for Softgel Manufacturing

For supplement brands working with a supplement contract manufacturer, the choice between fish oil and krill oil should be made during the formulation stage rather than simply based on raw material price.

A manufacturer should evaluate:

1. EPA and DHA specification

2. Oil concentration

3. Fill weight

4. Softgel size

5. Gelatin or vegetarian shell requirements

6. Antioxidant system

7. Oxidation specifications

8. Heavy metal and contaminant testing

9. Packaging requirements

10. Target shelf life

11. Country-specific regulatory requirements

12. Target production cost

These factors can affect both the final product quality and the total manufacturing cost.

Fish Oil vs. Krill Oil: Quick Summary

Fish oil and krill oil are both valuable sources of marine omega-3, but they serve somewhat different product-development needs.

Fish oil offers flexibility, relatively high EPA/DHA concentrations, and broad market acceptance. It is commonly used for mainstream omega-3 supplements and can be formulated in a variety of dosage forms.

Krill oil offers a more differentiated ingredient profile, including phospholipid-associated omega-3 and naturally occurring astaxanthin. It is commonly positioned as a premium omega-3 ingredient and is particularly suitable for softgel products.

For supplement brands, the best approach is to compare the complete raw material specification, EPA/DHA content, stability, regulatory requirements, MOQ, and finished-product cost before making a formulation decision.

Develop Your Fish Oil or Krill Oil Supplement with a Contract Manufacturer

Choosing the right omega-3 ingredient is only the first step. The next step is converting the ingredient into a stable, compliant, and commercially viable finished product.

A qualified supplement contract manufacturer can support brands with raw material sourcing, formula development, softgel manufacturing, testing, packaging, labeling, and quality control.

At Shandong Health Source Biological Engineering Co., Ltd., we provide OEM and ODM manufacturing services for dietary supplements, including fish oil softgels and krill oil softgels.

Whether you are developing a mainstream fish oil supplement or a premium krill oil product, the formulation can be customized according to your target EPA/DHA level, dosage, capsule size, packaging, market requirements, and target cost.

Looking for a reliable fish oil or krill oil supplement manufacturer? Contact Health Source to discuss your next omega-3 project.