Calanus Oil
Also called Calanus oil, Calanus finmarchicus oil, copepod oil, zooplankton oil, wax ester omega-3. One of 4 forms of omega-3 (fish oil, krill oil, algal oil) compared on this page.
Grade C for calanus oil itself: insulin resistance (homa) in obesity Fatty acid Last checked
The short answer
From 14 sourcesCalanus oil is an omega-3 oil from a tiny crustacean, with EPA and DHA bound as wax esters. It raised the omega-3 index as much as fish or krill oil at similar EPA+DHA. In trials of 2 to 4 g a day, it did not improve VO2max or memory, and insulin-resistance gains were small or limited to subgroups.
Every graded outcome on this page
9 rows · line = participants- CGrade CInsulin resistance (HOMA) in obesityTested calanus oiln 266
- CGrade COmega-3 index in older adultsTested calanus oiln 72
- CGrade COmega-3 index vs fish oil and krill oilTested calanus oiln 62
- CGrade CMaximal oxygen uptake (VO2max)Tested calanus oiln 58
- DGrade DBody fat with exercise in older untrained adultsOther or mixed formsn 134
- DGrade DShort-term memory and BDNF with exercise trainingTested calanus oiln 55
- DGrade DFunctional fitness with exercise in older womenTested calanus oiln 55
- DGrade DInsulin resistance in obesity with prediabetesTested calanus oiln 43
- DGrade DPlasma EPA and DHA after a single doseTested calanus oiln 18
- 1 more graded outcome, in the evidence chapter
Key facts
- What it is
- Oil from Calanus finmarchicus, a marine crustacean; over 86% of its fatty acids are wax esters7
- Omega-3 index (62 adults)
- +1.09 points on about 242 mg EPA+DHA a day, similar to fish oil (+1.0) and krill oil (+1.15)5
- Low EPA+DHA per gram
- 4 g of Calanus oil supplied 416 mg EPA+DHA, about half a single 840 mg Lovaza capsule7
- VO2max (58 adults)
- 2 g a day for 6 months: no change4
- Safety (117 adults)
- 2 g a day for a year: no change in safety labs; slightly more eczema, not significant6
What it is
Calanus oil comes from the North Atlantic copepod Calanus finmarchicus; its omega-3s EPA and DHA are mostly bound as wax esters.
Every omega-3 (fish oil, krill oil, algal oil) form, side by side
4 forms named in our sources. 2 have a page of their own; the rest show what our data holds, and say plainly where it holds nothing yet.
Omega-3 (fish oil, krill oil, algal oil) forms compared
4 forms · 2 with a page · Calanus Oil highlighted| 4 forms | Calanus OilYou are here | Fish oil (triglyceride, ethyl ester, re-esterified triglyceride) | Krill oil (phospholipid form)Read the page | Algal oil (mainly DHA) |
|---|---|---|---|---|
| Form-specific evidenceOutcomes tested on this form | CGrade CInsulin resistance (HOMA) in obesityTested this formRCT, n 266, 2025 CGrade COmega-3 index in older adultsTested this formRCT, n 72, 2021 +6 more on its page | Not graded | BGrade BTriglycerides in severe hypertriglyceridemiaTested this formRCT, n 520, 2022 CGrade CTriglycerides in borderline high or high triglyceridesTested this formRCT, n 300, 2014 +6 more on its page | Not graded |
| Studied dosesRange in its trials | 2,000–4,000mgmg of Calanus oil per day (about 104 mg EPA+DHA per gram)6274 | No data yet | 500–4,000mgg of krill oil per day9235111312 | No data yet |
| Absorption in people | Same omega-3 index rise as fish and krill oil at matched EPA+DHA; plasma EPA exposure higher than ethyl esters in a single-dose study.57 | Natural and re-esterified triglycerides and free fatty acids have somewhat higher bioavailability than ethyl esters, but all forms raise plasma EPA and DHA.16 | Matched-dose trials show similar blood EPA+DHA to fish oil; some small studies suggest somewhat higher uptake, others do not.671 | DHA from algal-oil capsules matched cooked salmon in a small 2-week trial.81 |
| GI tolerance | No effect on safety labs over a year at 2 g a day; slightly more eczema, not significant after multiple-comparison control.6 | Usually mild: fishy taste, bad breath, heartburn, nausea, GI discomfort, diarrhea, headache, odoriferous sweat.1 | No head-to-head tolerance data in our sources. Krill are crustaceans; prescription omega-3 labels advise caution with fish or shellfish hypersensitivity.9 | Generally well tolerated in the comparison trial.8 |
| Studied for | Omega-3 status, insulin resistance, fitness, memory, body fat | Cardiovascular events, triglycerides, atrial fibrillation, dry eye | Blood EPA+DHA levels (bioavailability) | Blood DHA levels; the vegan option |
- Calanus OilYou are here
- Form-specific evidence
- CGrade CInsulin resistance (HOMA) in obesityTested this formRCT, n 266, 2025CGrade COmega-3 index in older adultsTested this formRCT, n 72, 2021+6 more on its page
- Absorption in people
- Same omega-3 index rise as fish and krill oil at matched EPA+DHA; plasma EPA exposure higher than ethyl esters in a single-dose study.57
- GI tolerance
- No effect on safety labs over a year at 2 g a day; slightly more eczema, not significant after multiple-comparison control.6
- Studied for
- Omega-3 status, insulin resistance, fitness, memory, body fat
- Fish oil (triglyceride, ethyl ester, re-esterified triglyceride)
- Form-specific evidence
- Not graded
- Studied doses
- No data yet
- Absorption in people
- Natural and re-esterified triglycerides and free fatty acids have somewhat higher bioavailability than ethyl esters, but all forms raise plasma EPA and DHA.16
- GI tolerance
- Usually mild: fishy taste, bad breath, heartburn, nausea, GI discomfort, diarrhea, headache, odoriferous sweat.1
- Studied for
- Cardiovascular events, triglycerides, atrial fibrillation, dry eye
- Krill oil (phospholipid form)Read the page
- Form-specific evidence
- BGrade BTriglycerides in severe hypertriglyceridemiaTested this formRCT, n 520, 2022CGrade CTriglycerides in borderline high or high triglyceridesTested this formRCT, n 300, 2014+6 more on its page
- Absorption in people
- Matched-dose trials show similar blood EPA+DHA to fish oil; some small studies suggest somewhat higher uptake, others do not.671
- GI tolerance
- No head-to-head tolerance data in our sources. Krill are crustaceans; prescription omega-3 labels advise caution with fish or shellfish hypersensitivity.9
- Studied for
- Blood EPA+DHA levels (bioavailability)
- Algal oil (mainly DHA)
- Form-specific evidence
- Not graded
- Studied doses
- No data yet
- GI tolerance
- Generally well tolerated in the comparison trial.8
- Studied for
- Blood DHA levels; the vegan option
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Grade C for calanus oil itself. 8 outcomes on this page were tested with calanus oil: insulin resistance (homa) in obesity; omega-3 index in older adults; omega-3 index vs fish oil and krill oil; maximal oxygen uptake (vo2max); short-term memory and bdnf with exercise training; functional fitness with exercise in older women; insulin resistance in obesity with prediabetes; plasma epa and dha after a single dose (RCT, n 266, 2025). Rows that tested other or mixed forms describe omega-3 (fish oil, krill oil, algal oil) in general, not calanus oil. For the overall evidence, see the Omega-3 (fish oil, krill oil, algal oil) page.
Trial map
9 graded outcomes, largest study first9 graded outcomes: 5 improved, 2 mixed, 2 no effect. The largest, a 2025 randomized trial of 266 people on insulin resistance (HOMA) in obesity, found mixed results.
1Insulin resistance (HOMA) in obesity
Mixed · Grade C · RCT, 266 people, 2025
Adults with obesity and different insulin-resistance phenotypes
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Insulin resistance (HOMA) in obesity | Mixed | 266 | Grade C · RCT, 2025 | Adults with obesity and different insulin-resistance phenotypes |
| Body fat with exercise in older untrained adults | Improved | 134 | Grade D · RCT, 2020 | Untrained adults around age 59 (96 women, 38 men), BMI about 28 |
| Omega-3 index in older adults | Improved | 72 | Grade C · RCT, 2021 | Healthy adults around age 59 (BMI about 28) in a twice-weekly exercise programme |
| Omega-3 index vs fish oil and krill oil | Improved | 62 | Grade C · RCT, 2023 | Healthy adults (mean age 30) |
| Maximal oxygen uptake (VO2max) | No effect | 58 | Grade C · RCT, 2022 | Healthy, fit adults aged 30 to 50 |
| Short-term memory and BDNF with exercise training | No effect | 55 | Grade D · RCT, 2022 | Healthy women aged 65 to 80 in a 16-week exercise program |
| Functional fitness with exercise in older women | Mixed | 55 | Grade D · RCT, 2020 | Healthy sedentary women aged 65 to 80 in a 16-week exercise program |
| Insulin resistance in obesity with prediabetes | Improved | 43 | Grade D · RCT, 2022 | Adults with obesity (mean BMI 31.7) and prediabetes |
| Plasma EPA and DHA after a single dose | Improved | 18 | Grade D · PK study, 2016 | Healthy adults |
Every graded row
9 rowsShowing 9 of 9 outcomes. Human trials only.
CGrade CInsulin resistance (HOMA) in obesityInsulin resistance · tested calanus oilSubgroup gains onlyRCT
n 266 · 2025
Mixed The effect on HOMA depended on baseline HOMA (interaction p = 0.011); 2 g a day plus lifestyle change improved HOMA in a post hoc test, and 4 g a day helped only people with mild insulin resistance.
- Design
- RCT, n = 266, 2025
- Population
- Adults with obesity and different insulin-resistance phenotypes
- Form
- Calanus oil, with or without a lifestyle program
- Dose
- 2 or 4 g a day
- Duration
- 12 weeks
- Source
- Reference 2 · PubMed 40278260 (opens PubMed)
CGrade COmega-3 index in older adultsOmega-3 status · tested calanus oil+1.3 pointsRCT
n 72 · 2021
Improved The omega-3 index rose from 6.07% to 7.37% with Calanus oil and did not change significantly with exercise alone (6.01% to 6.15%).
- Design
- RCT, n = 72, 2021
- Population
- Healthy adults around age 59 (BMI about 28) in a twice-weekly exercise programme
- Form
- Calanus oil plus exercise vs exercise alone
- Dose
- 2 g a day (109 mg EPA, 87 mg DHA and 124 mg stearidonic acid)
- Duration
- 12 weeks
- Source
- Reference 11 · PubMed 32698912 (opens PubMed)
CGrade COmega-3 index vs fish oil and krill oilOmega-3 status · tested calanus oilSame rise as fish oilRCT
n 62 · 2023
Improved The omega-3 index rose 1.09 points with Calanus oil, 1.0 with fish oil and 1.15 with krill oil (all p < 0.001), with no difference between oils.
- Design
- RCT, n = 62, 2023
- Population
- Healthy adults (mean age 30)
- Form
- Calanus oil vs fish oil vs krill oil
- Dose
- 4 capsules a day (242 mg EPA+DHA)
- Duration
- 12 weeks
- Source
- Reference 5 · PubMed 36960737 (opens PubMed)
CGrade CMaximal oxygen uptake (VO2max)Fitness · tested calanus oilNo effectRCT
n 58 · 2022
No effect VO2max at 6 months was 49.7 vs 49.5 mL/kg/min with placebo, and clinical measures did not change.
- Design
- RCT, n = 58, 2022
- Population
- Healthy, fit adults aged 30 to 50
- Form
- Calanus oil vs placebo
- Dose
- 2 g a day
- Duration
- 6 months
- Source
- Reference 4 · PubMed 35998897 (opens PubMed)
DGrade DBody fat with exercise in older untrained adultsBody fat · other or mixed formsSome fat loss with exerciseRCT
n 134 · 2020
Improved Body fat fell most with exercise plus Calanus oil (-1.70 kg) and exercise plus diet advice (-1.41 kg); glucose and blood lipids did not change in any group.
- Design
- RCT, n = 134, 2020
- Population
- Untrained adults around age 59 (96 women, 38 men), BMI about 28
- Form
- Exercise plus Calanus oil vs exercise alone, exercise plus diet advice, or control
- Dose
- 2 g a day
- Duration
- 12 weeks
- Source
- Reference 8 · PubMed 32708396 (opens PubMed)
DGrade DShort-term memory and BDNF with exercise trainingMemory · tested calanus oilNo added effectRCT
n 55 · 2022
No effect Memory improved with exercise in both groups, with no added effect of Calanus oil; BDNF did not change.
- Design
- RCT, n = 55, 2022
- Population
- Healthy women aged 65 to 80 in a 16-week exercise program
- Form
- Calanus oil vs placebo, both with exercise
- Dose
- Not stated in the abstract
- Duration
- 16 weeks
- Source
- Reference 3 · PubMed 35990804 (opens PubMed)
DGrade DFunctional fitness with exercise in older womenFitness · tested calanus oilChair stand onlyRCT
n 55 · 2020
Mixed Fitness and body composition improved with exercise in both groups, with no added effect of Calanus oil on most measures; lower-body strength (chair stand test) improved more with Calanus oil.
- Design
- RCT, n = 55, 2020
- Population
- Healthy sedentary women aged 65 to 80 in a 16-week exercise program
- Form
- Calanus oil vs sunflower-oil placebo, both with exercise
- Dose
- Not stated in the abstract
- Duration
- 16 weeks
- Source
- Reference 12 · PubMed 32074977 (opens PubMed)
DGrade DInsulin resistance in obesity with prediabetesInsulin resistance · tested calanus oilHOMA-IR -0.9RCT
n 43 · 2022
Improved After 12 weeks of Calanus oil, fasting insulin (-2.9 mU/L), HOMA-IR (-0.9) and a liver insulin-resistance index improved; HbA1c, 2-hour glucose and muscle insulin sensitivity did not change.
- Design
- RCT, n = 43, 2022
- Population
- Adults with obesity (mean BMI 31.7) and prediabetes
- Form
- Calanus oil vs paraffin-oil placebo
- Dose
- 2 g a day
- Duration
- 12 weeks, with a further check at week 16
- Source
- Reference 10 · PubMed 35057577 (opens PubMed)
DGrade DPlasma EPA and DHA after a single doseAbsorption · tested calanus oilAbsorbed like ethyl estersPK study
n 18 · 2016
Improved Both raised plasma EPA and DHA; total EPA+DHA exposure did not differ, and plasma EPA exposure over 48 to 72 hours was higher with Calanus oil (514 vs 313 µg·h/mL).
- Design
- PK study, n = 18, 2016
- Population
- Healthy adults
- Form
- Calanus oil vs Lovaza (omega-3 ethyl esters)
- Dose
- 4 g Calanus oil (260 mg EPA + 156 mg DHA) vs 1 Lovaza capsule (465 mg EPA + 375 mg DHA)
- Duration
- Single doses, 72 hours of sampling
- Source
- Reference 7 · PubMed 27604086 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
When trials measured an effect
1 outcomeInteractions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
What Calanus Oil meets
2 cited rowsMedicines 2
Supplements and foods 0
No supplement rows in our sources.
- Reference summary
Choose a medicine or supplement above to read its cited rows here.
Also cited:
Antiplatelet drugs
ReviewReference summary
Antiplatelet drugs, for example aspirin, clopidogrel: LiverTox notes omega-3 fatty acids can affect platelet function and raise bleeding risk, particularly with antithrombotic therapy. No Calanus-specific data.
Source 14, LiverTox (NCBI Bookshelf) (2017)
Warfarin and similar anticoagulants
NIH fact sheetReference summary
Warfarin and similar anticoagulants: For omega-3s in general, ODS says fish oil might raise INR with warfarin, though most research finds 3 to 6 g a day of fish oil does not significantly change anticoagulation. LiverTox lists a higher risk of bleeding with omega-3s, particularly with anticoagulant and antiplatelet drugs.
Source 1, NIH Office of Dietary Supplements (2025); Source 14, LiverTox (NCBI Bookshelf) (2017)
Interactions
2 agents| Agent | What the source says | Evidence |
|---|---|---|
| Medicines2 | ||
| Warfarin and similar anticoagulants | For omega-3s in general, ODS says fish oil might raise INR with warfarin, though most research finds 3 to 6 g a day of fish oil does not significantly change anticoagulation. LiverTox lists a higher risk of bleeding with omega-3s, particularly with anticoagulant and antiplatelet drugs.114 | NIH fact sheet |
| Antiplatelet drugse.g. aspirin, clopidogrel | LiverTox notes omega-3 fatty acids can affect platelet function and raise bleeding risk, particularly with antithrombotic therapy. No Calanus-specific data.14 | Review |
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Calanus Oil and your picks, and between your picks.
- Loading names…
Add a supplement or medicine you take to check it against Calanus Oil.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
7 groups- Crustacean source
- Calanus finmarchicus is a marine crustacean; the trials here did not report results in people with shellfish allergy.7
- Blood thinners
- ODS notes fish oil might raise INR with warfarin, and LiverTox lists a higher bleeding risk with omega-3s alongside anticoagulant or antiplatelet drugs; people on these medicines should tell their clinician about omega-3 products.114
- Eczema
- In the year-long safety trial, eczema was slightly more common on Calanus oil, though not significant and not attributed to treatment.6
- Pregnancy and breastfeeding
- No trial has tested Calanus oil in pregnancy or breastfeeding, and LactMed has no entry for it, so there are no reliable safety data. The trials cited here enrolled non-pregnant adults; see the arsenic note below.5613
- Arsenic content
- A 2022 analysis of 32 marine supplements found higher total arsenic (over 1,000 ng/g) in Calanus oil, krill oil, seaweed and unprocessed fish products, and arsenic hydrocarbons (169 to 2,048 ng/g) in Calanus oil and unprocessed fish and fish liver oils; inorganic arsenic was found only in seaweed products.13
- Liver
- LiverTox gives omega-3 fatty acids a likelihood score of E (unlikely cause of clinically apparent liver injury). It has no Calanus-specific entry.14
- Medicines and surgery
- NCCIH advises telling your health care providers about every supplement you use.9
How to read the label
What to check on the Supplement Facts panel.
How to read the label
1 checksFrequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
6 answersDoes Calanus oil help insulin resistance or weight?
Mixed. In 43 adults with obesity and prediabetes, 2 g a day lowered fasting insulin and HOMA-IR within the Calanus group, without changing HbA1c. In 266 adults with obesity, effects on HOMA appeared only in subgroups or with lifestyle change. With exercise, 2 g a day matched diet advice for fat loss in a pilot.1028
Does Calanus oil improve fitness or memory?
Can I take Calanus oil if I have a shellfish allergy?
There are no data. Calanus finmarchicus is a marine crustacean, and none of the trials cited here reported results in people with shellfish allergy, so people with a crustacean allergy should ask their clinician first.7
Is Calanus oil safe?
In 117 adults, 2 g a day for a year did not change safety labs or vital signs; eczema was slightly, not significantly, more common.6
Is Calanus oil better than fish oil?
For omega-3 status, no: at about 245 mg EPA+DHA a day, Calanus, fish and krill oil raised the omega-3 index by the same amount over 12 weeks.5
Sources
14 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
14 sources- 1Omega-3 Fatty Acids: Fact Sheet for Health Professionals (updated August 22, 2025)Fact sheet NIH Office of Dietary Supplements, 2025 · ods.od.nih.gov
- 2Calanus Oil and Lifestyle Interventions Improve Glucose Homeostasis in Obese Subjects with Insulin Resistance.RCT Mar Drugs, 2025 · PMID 40278260
- 3Calanus Oil Supplementation Does Not Further Improve Short-Term Memory or Brain-Derived Neurotrophic Factor in Older Women Who Underwent Exercise Training.RCT Clin Interv Aging, 2022 · PMID 35990804
- 4No Effect of Calanus Oil on Maximal Oxygen Uptake in Healthy Participants: A Randomized Controlled Study.RCT Int J Sport Nutr Exerc Metab, 2022 · PMID 35998897
- 5Equal bioavailability of omega-3 PUFA from Calanus oil, fish oil and krill oil: A 12-week randomized parallel study.RCT Lipids, 2023 · PMID 36960737
- 6Clinical safety evaluation of marine oil derived from Calanus finmarchicus.RCT Regul Toxicol Pharmacol, 2016 · PMID 27233921
- 7Wax Ester Rich Oil From The Marine Crustacean, Calanus finmarchicus, is a Bioavailable Source of EPA and DHA for Human Consumption.PK study Lipids, 2016 · PMID 27604086
- 8Effects of Exercise Combined with a Healthy Diet or Calanus finmarchicus Oil Supplementation on Body Composition and Metabolic Markers-A Pilot Study.RCT Nutrients, 2020 · PMID 32708396
- 9Using Dietary Supplements WiselyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
- 10Marine Oil from C. finmarchicus Enhances Glucose Homeostasis and Liver Insulin Resistance in Obese Prediabetic Individuals.RCT Nutrients, 2022 · PMID 35057577
- 11Intake of Calanus finmarchicus oil for 12 weeks improves omega-3 index in healthy older subjects engaging in an exercise programme.RCT Br J Nutr, 2021 · PMID 32698912
- 12Effect of Calanus Oil Supplementation and 16 Week Exercise Program on Selected Fitness Parameters in Older Women.RCT Nutrients, 2020 · PMID 32074977
- 13Exposure to arsenolipids and inorganic arsenic from marine-sourced dietary supplements.Observational Chemosphere, 2022 · PMID 35182530
- 14Omega-3 Fatty AcidsDatabase LiverTox (NCBI Bookshelf), 2017 · ncbi.nlm.nih.gov
What changed
Every dated change to this page: what changed, who made it and why.
Change log
3 entries| Date | Change | Who and why |
|---|---|---|
| evidence; interactions; who should avoid; FAQ; questions; time to effect | PubMed search of every Calanus human study through 2026 found three trials missing from the table: omega-3 index in older adults (72, 2021), insulin resistance in prediabetes (43, 2022) and fitness in older women (55, 2020), now added. Added a pregnancy and breastfeeding note (no LactMed entry; no data), an arsenic note from a 2022 analysis of marine supplements, the LiverTox Omega-3 Fatty Acids entry (NBK548910, score E) for liver and bleeding risk, an antiplatelet interaction, a time-to-effect row, a shellfish-allergy FAQ, page questions and goal-hub links. A companion report from the older-women trial on cardiac output (2021) was left out as a secondary measure. | Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md |
| Goals | Added the Brain & focus goal (focus): the page already has a graded human row on a memory or thinking outcome (“Short-term memory and BDNF with exercise training”, Grade D). No evidence row, grade or text changed. | Writer: Kymata Health EditorialTrigger: Update |
| all | Initial editorial evidence review. Every PMID checked against NCBI E-utilities esummary (title, year, journal) and each cited abstract read; numbers taken from the abstracts. Maker funding disclosed (Zooca Lipids 2025; capsules from Calanus AS 2020); null VO2max and memory trials shown. Interaction from the ODS omega-3 fact sheet (omega-3s in general). Filed as a form of omega-3. Where to buy: we didn’t list a product; none of the stores we checked sells Calanus oil. | Writer: Kymata Health EditorialTrigger: new page |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.