Krill oil is the other major source of marine omega-3s alongside fish oil, and it is usually sold on a bioavailability story — that its phospholipid-bound EPA and DHA absorb better than the triglyceride or ethyl-ester forms in fish oil. Brands abroad ask for a Japan-made krill oil product expecting that story to be settled science.
This guide is for brand owners planning a Japan-made krill oil product. It covers what randomised trials actually found when they compared krill oil with fish oil, krill oil’s natural astaxanthin content, the shellfish allergen question that fish oil does not have, and what to fix before asking for a quotation.
Health supplements are foods, not medicines, and are not a substitute for medical treatment. Nothing here is a claim that any product prevents, treats or cures a disease.
💬 Planning a krill oil product made in Japan? We check the full formula against Japanese food law first. See Japan-made supplement OEM.
What the research shows
Randomised crossover trials comparing krill oil with fish oil have reached different conclusions — one found significantly higher EPA and DHA bioavailability from krill oil, another found no statistically significant difference.
| Study | Design | Reported result |
|---|---|---|
| Randomised, single-dose, cross-over trial, Lipids in Health and Disease 2015;14:19 (PMID 25884846) | 15 healthy subjects; krill oil, krill meal and fish oil, each providing a matched dose of EPA and DHA, compared over 72 hours | The 72-hour incorporation of EPA and DHA into plasma phospholipids was significantly higher after krill oil than after fish oil; krill meal and fish oil did not differ from each other |
| Double-blinded, randomised crossover trial, Lipids in Health and Disease 2011;10:145 (PMID 21854650) | 12 healthy men; krill oil (phospholipid-bound), re-esterified triglyceride fish oil, and ethyl-ester fish oil, each compared over 72 hours with a 14-day washout between arms | Krill oil showed the highest mean incorporation into plasma phospholipids, followed by the triglyceride and then the ethyl-ester form, but the differences were not statistically significant given the variation between subjects |
Two points worth keeping in view:
- Small, short trials. Both trials are single-dose, short-term crossover studies in small groups of healthy subjects, not trials of daily supplementation over months or of any disease outcome.
- Not a settled comparison. The two trials point the same direction but disagree on whether the difference reaches statistical significance. A fair summary is that bioavailability evidence for krill oil over fish oil is mixed, not proven.
Checked against the published abstracts on 25 September 2026.
What Japanese products say
Krill oil has appeared in Japan’s Foods with Function Claims system, notified for EPA/DHA-related functions such as joint comfort in daily movement.
Under the Foods with Function Claims system, the notifying business is responsible for the scientific evidence behind the stated function and submits it to the Consumer Affairs Agency before sale. The wording used in these notifications describes everyday, healthy-function states, not medical conditions.
Two lessons for a brand abroad:
- The notified wording is specific to the formula tested. It applies to the amount and form the notifying business used, not to “krill oil” as a category.
- A Japanese notification is not a global endorsement. It is a Japanese regulatory mechanism for products sold in Japan. Your label abroad follows your own market’s rules.
💬 Need an evidence summary for your regulatory adviser that separates the bioavailability trials from any claim wording? We prepare it with the manufacturing documents. Tell us your market.
Wording that stays on safe ground
Describe krill oil by its composition and by what has been studied, not by an assumed superiority over fish oil.
| Safer wording | Wording to avoid |
|---|---|
| ”Contains phospholipid-bound EPA and DHA from krill oil" | "Better absorbed than fish oil” stated as settled fact |
| ”Studied for EPA and DHA bioavailability compared with fish oil” | Any disease-risk or treatment claim |
| Naming the trial you cite, with its size and limits | ”Clinically proven” without naming the study |
How krill oil is formulated
Krill oil is oil-soluble and typically supplied and sold as a soft capsule, like fish oil, but two specification points are unique to krill: its natural astaxanthin content and its shellfish allergen status.
| Dosage form | Why brands choose it | What to weigh up |
|---|---|---|
| Soft capsule | The standard format for an oil-based marine extract; the shell limits oxygen contact and reduces odour | Shell material for dietary suitability |
| Liquid oil | Higher daily doses without multiple capsules | Faster oxidation once opened; needs refrigeration guidance |
Decisions that shape the specification:
- Astaxanthin content. Krill oil naturally contains astaxanthin, the red carotenoid that gives it its colour; the amount varies by supplier and extraction method, so ask for the astaxanthin content on the certificate of analysis rather than assuming a figure.
- Shellfish allergen status. Krill is a crustacean, and studies have detected tropomyosin — the main crustacean allergen — in commercial krill oil products, even after the refining process. Krill oil needs the same crustacean allergen declaration as shrimp or crab in markets that require it, and this is a real consideration for anyone with a shellfish allergy.
- EPA and DHA content and form. Confirm the EPA and DHA content per gram, and ask the supplier whether the material is characterised as phospholipid-bound, since that is the basis of any bioavailability comparison you plan to reference.
- Oxidation and odour. Like fish oil, krill oil is prone to oxidation. Antioxidants, oxygen-impermeable packaging and appropriate storage all affect shelf stability and odour.
- Companion ingredients. Krill oil is sometimes combined with additional astaxanthin or other marine ingredients. Every companion ingredient needs its own check against Japanese food law.
The check that comes first
Every ingredient must be permitted in foods in Japan, or a Japanese factory cannot make the product.
Krill oil itself is used in Japanese foods. The allergen declaration is the point most likely to be missed by a brand new to this ingredient, alongside any companion ingredient in a combined formula. See the Japan-made supplement OEM page, and compare with our omega-3 fish oil and astaxanthin guides if you are weighing marine-oil options or a combined formula.
Before you ask for a quotation
A factory can quote accurately once the source, the amount, the form and the allergen declaration are fixed.
- Krill oil source and EPA/DHA content per gram
- Astaxanthin content on the certificate of analysis
- Daily amount and servings per pack
- Dosage form and packaging
- Shellfish/crustacean allergen labelling in your target markets
- Countries you will sell in, and first order and annual volume
💬 Ready to design a Japan-made krill oil product? Send us the concept — source, daily amount, form and the countries you will sell in.
Frequently asked questions
1. Is krill oil better absorbed than fish oil?
The evidence is mixed. A 2015 trial found significantly higher plasma incorporation of EPA and DHA from krill oil than from fish oil; a 2011 trial found krill oil trended higher but the difference was not statistically significant. Describe krill oil as studied for bioavailability, not as proven superior.
2. Does krill oil contain astaxanthin?
Yes, krill oil naturally contains astaxanthin, which gives it its red colour. The amount varies between suppliers, so ask for the figure on the certificate of analysis rather than assuming one.
3. Is krill oil safe for people with a shellfish allergy?
It is a genuine concern. Krill is a crustacean, and studies have detected the crustacean allergen tropomyosin in commercial krill oil even after refining. A crustacean allergen declaration is needed in markets that require it.
4. How is krill oil usually formulated?
As a soft capsule, in the same way as fish oil. It is oil-soluble and prone to oxidation, so antioxidants and appropriate packaging matter for shelf stability.
5. Can krill oil use the same health wording as fish oil?
No. Any notified function or claim applies to the specific formula and amount that was studied or notified, not to krill oil or omega-3s as a general category.
Sources: “Bioavailability of fatty acids from krill oil, krill meal and fish oil in healthy subjects–a randomized, single-dose, cross-over trial”, Lipids in Health and Disease 2015;14:19 (PMID 25884846); “Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations—a comparative bioavailability study of fish oil vs. krill oil”, Lipids in Health and Disease 2011;10:145 (PMID 21854650); “Detection of tropomyosin and determination of proteins in crustacean oils”, Food Chemistry 2013 (PMID 23768329); Consumer Affairs Agency notifications for Foods with Function Claims. Checked on 25 September 2026.