Calamari oil

Calamari Oil

1. Identity: Botanical/Chemical Name, Source, and Forms

Nomenclature and Taxonomic Source

Calamari oil is a marine-derived lipid supplement obtained from squid, members of the class Cephalopoda. It is extracted from the visceral organs (most commonly the liver/hepatopancreas) of squid species, with Loligo pealei and related loliginid species being among those used commercially. Commercial production also draws heavily on the Argentinian shortfin squid (Illex argentinus), whose lifecycle of 12–14 months means the population is constantly reproducing. Other commercially relevant loliginid squid species include Uroteuthis duvaucelii, Uroteuthis edulis, Uroteuthis chinensis, and Loliolus uyii.

The principal active components are the long-chain omega-3 polyunsaturated fatty acids (LC-PUFAs): docosahexaenoic acid (DHA; 22:6 n-3) and eicosapentaenoic acid (EPA; 20:5 n-3). Crude squid oil is a valuable source for DHA and represents a sustainable alternative to tuna oil, which has historically been the major commercial source for this fatty acid.

Common Forms and Preparations

Industry descriptions indicate that squid delivers approximately 30% omega-3 in non-concentrated natural oil, with a fatty acid profile similar to tuna and salmon in that DHA levels are higher than EPA levels. Supplements are offered as:

• Softgel capsules — the most prevalent consumer form, typically containing a mixture of calamari oil and antioxidant stabilizers.
• Liquid oil — for example, one commercial product provides a 5 mL serving (one teaspoon) delivering 800 mg DHA and 400 mg EPA. Ingredients in one such liquid formulation are: calamari oil (squid), natural citrus flavor, sunflower oil, d-alpha tocopherol (vitamin E soy), and rosemary extract, with each 5 mL serving providing 45 calories, 5 g total fat, 110 mg cholesterol, 800 mg DHA, and 400 mg EPA.
• Concentrated oil blends — processed forms that increase DHA/EPA density beyond the natural ~30% omega-3 content of crude squid oil.

The calamari oil derived from squid trimmings is further refined and purified using processing technology that includes cold filtration, organic filtration, detoxification, and concentration methods. Antioxidants such as mixed tocopherols, ascorbyl palmitate, and rosemary extract are routinely added to retard oxidative rancidity during storage.

2. Historical and Traditional Use

Squid in Culinary Traditions

Squid as a whole food has a long history in Mediterranean, East Asian, and Southeast Asian cuisines. Squid are closely related to octopus and are widely consumed in Asian and Mediterranean countries. In Mediterranean cultures (Spain, Italy, Greece, Portugal), squid has been a staple seafood for centuries, prepared fried, grilled, braised, or stuffed. In Japan, Korea, and China, squid features prominently in traditional diets, consumed fresh, dried, or fermented.

Traditional diets that included squid were believed in various cultures to nourish the blood, boost vitality, and improve stamina, though the therapeutic concentration of DHA seen in modern calamari oil supplements was not present in whole food form.

Emergence as a Refined Supplement

The rise of calamari oil as a refined supplement began in response to increasing demand for cleaner, more sustainable omega-3 sources. Once considered a waste product, squid visceral tissue is now used to manufacture DHA-rich omega-3 products. Standard Process chose squid as the source for its Calamari Omega-3 Liquid supplement, which launched in 2010. A proportion of the annual global squid harvest is not utilized for direct human consumption, and these offcuts that would normally be discarded as waste are used to manufacture calamari oil; all by-products of a catch are utilized, so no additional squid must be caught to obtain the raw material.

3. Key Constituents and Active Compounds

Fatty Acid Profile

Calamari oil, derived from squid, is rich in omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Its defining characteristic relative to other marine oil supplements is its fatty acid ratio:

• DHA (docosahexaenoic acid; 22:6 n-3): Calamari oil typically contains a higher DHA-to-EPA ratio than fish oil or krill oil, with a DHA content often reported at 50–60% of total fatty acids, offering targeted support for neurological and cognitive function.
• EPA (eicosapentaenoic acid; 20:5 n-3): Present at lower levels than DHA. Calamari oil contains a DHA-to-EPA ratio of approximately 2:1. Fish oil and krill oil contain more EPA than calamari oil, but squid is considered one of the richest marine sources of DHA, containing more DHA than fish oil and krill oil.
• Other fatty acids: Unlike krill and fish, which contain more EPA omega-3 than DHA omega-3, squid's omega-3 ratio is reversed; the resulting oil can therefore be tailored to DHA-targeted products.

Marine oils derived from fish, krill, shellfish, calamari, or algae differ from terrestrial plant sources of omega-3 fatty acids in that they contain the long-chain polyunsaturated fatty acids (LC-PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in preformed, immediately utilizable form.

Established Mechanisms of Action

The bioactivity of calamari oil is attributed to its DHA and EPA content. Their mechanisms of action, established in the broader omega-3 literature, include:

• Structural membrane incorporation: Among the long-chain omega-3 fatty acids, DHA is the principal PUFA constituent of brain neurons, retinal cells, and primary structural component of skin, sperm, and testicular tissue. Apart from being an important structural component of cellular membranes, it performs functions in transport of neurotransmitters and amino acids and modulates the functioning of ion channels and responses of retinal pigments.
• Anti-inflammatory and immune modulation: Both DHA and EPA have anti-thrombotic, anti-inflammatory, and anti-oxidative properties. EPA and DHA supplementation decreases monocyte synthesis of cytokines TNF-α and IL-1β, with cytokine synthesis decreasing as cellular EPA concentrations increase. More recently, EPA and DHA derivatives — resolvins and protectins — have been shown to initiate the resolution of inflammation by enhancing macrophage clearance of leukocytes.
• Triglyceride reduction and cardiovascular effects: Omega-3 fatty acids may reduce the risk of atherosclerotic cardiovascular disease (ASCVD) events through various mechanisms, including triglyceride (TG) lowering, membrane stabilization, and antithrombotic, anti-inflammatory, or antiarrhythmic properties. DHA significantly reduces triglycerides, lowers heart rate, lowers blood pressure, and has been associated with reduction of the risk of cardiac death.
• Ion channel modulation: Anti-fibrotic effects of n-3 PUFAs have been described, with potential impacts on heart failure with preserved ejection fraction; furthermore, n-3 PUFAs can modify ion channels, with a favorable impact on arrhythmias.
• Lipid metabolism via PPAR activation: Potential mechanisms for DHA's effects on hepatic lipid accumulation include reduction of triglyceride synthesis via activation of peroxisome proliferator-activated receptors (PPAR-α and PPAR-γ), which accelerates fatty acid oxidation in liver mitochondria.

4. Scientific Evidence by Area of Use

Important Methodological Note

Most clinical research has been conducted with generic fish oil or algae-derived DHA/EPA rather than specifically calamari oil. Despite this, the biochemical similarity and bioavailability of DHA/EPA from calamari oil are recognized as supporting factors. The use of calamari oil to support health is scientifically grounded through the established role of omega-3s generally, but direct evidence for calamari oil itself is more limited compared to fish oil. The sections below therefore distinguish between evidence derived specifically from calamari oil trials and the broader, more robust omega-3 literature that is applicable by chemical equivalence.

4a. Cardiovascular Health

Multiple randomized controlled trials and meta-analyses have demonstrated that omega-3 supplementation can reduce triglyceride levels, may modestly lower blood pressure, and can have anti-inflammatory effects. Some studies suggest that omega-3 fatty acids could reduce the risk of major cardiovascular events, though the evidence is mixed regarding their impact on overall mortality or prevention of heart attacks and strokes in all populations.

Key landmark clinical evidence includes: the REDUCE-IT trial, in which icosapent ethyl (a highly purified ethyl ester of EPA) in patients with established ASCVD or high-risk individuals showed a significant 25% relative reduction in a primary composite cardiovascular endpoint (cardiovascular death, non-fatal MI, non-fatal stroke, coronary revascularization, or unstable angina), corresponding to an absolute risk reduction of 4.8%.

However, the picture for combined EPA+DHA is more complicated: in REDUCE-IT, 4 g of icosapent ethyl (EPA) produced cardiovascular benefits in people receiving statin therapy; however, in STRENGTH, a high-dose combination of EPA and DHA did not show such benefits in people with high cardiovascular risk. The conflicting results may be attributed to differences in the types (EPA+DHA versus EPA alone), doses, or comparators used, as well as distinct study populations.

A meta-analysis of 38 randomized controlled trials found that omega-3 fatty acids were associated with reducing cardiovascular mortality and other cardiovascular outcomes, and a sub-analysis of EPA-only trials showed greater relative risk reductions in cardiovascular outcomes than those using EPA+DHA.

While the benefits of omega-3s for cardiovascular health are well established in the broader literature, most research has focused on fish oil rather than calamari oil specifically. The FDA has stated that supportive but not conclusive research has shown that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease, and that consuming EPA and DHA combined may help lower blood pressure in the general population — yet FDA has concluded that the evidence is inconsistent and inconclusive.

Evidence strength: For omega-3 fatty acids generally, evidence for triglyceride reduction is strong and consistent. Evidence for reduction in major cardiovascular events is mixed — positive for EPA monotherapy at high dose, but inconclusive for combined EPA+DHA formulations such as those found in calamari oil. No large-scale RCTs have been conducted exclusively with calamari oil.

4b. Brain Health and Cognitive Function

Omega-3 polyunsaturated fatty acids exhibit neuroprotective properties and represent a potential treatment for a variety of neurodegenerative and neurological disorders. Beneficial effects in mood disorders have more consistently been reported in clinical trials using EPA, whereas with neurodegenerative conditions such as Alzheimer's disease, the focus has been on DHA, which is quantitatively the most important omega-3 PUFA in the brain.

DHA and EPA have been shown to have important roles in reducing inflammation, supporting cardiovascular health, and regulating mood and behavior. DHA is especially abundant in the brain and retina, and plays crucial roles in brain development, learning, memory, and vision.

Several randomized controlled trials and meta-analyses have shown that supplementation with omega-3s may help maintain normal cognitive function, especially in aging populations, and may provide some benefit in mild cognitive impairment, though results in healthy individuals and in the prevention of neurodegenerative diseases are mixed.

Evidence strength: Moderate. Observational and mechanistic data for DHA's role in brain structure are strong, but RCT evidence for clinical cognitive outcomes is inconsistent, especially in healthy populations. No RCTs have been conducted specifically with calamari oil for cognitive endpoints.

4c. Prenatal and Infant Neurodevelopment

DHA has been shown to be particularly important for fetal brain development, optimal development of motor skills and visual acuity in infants, lipid metabolism in children and adults, and cognitive support in the elderly.

DHA supports the maturation of neural pathways necessary for organized sleep patterns in infants, with supplementation during pregnancy associated with longer gestational periods and improved neurodevelopmental and behavioral outcomes in some trials, although clinical findings vary due to differences in supplementation timing, dosage, and study populations.

Clinical trial evidence is mixed. Randomized clinical trials of DHA supplementation during pregnancy and/or lactation, and of term infants, have not shown a consistent benefit or harm on neurodevelopment of healthy children born at term; the evidence does not support DHA supplementation of healthy pregnant and lactating women or healthy infants. On the other hand, specific studies have demonstrated that DHA supplementation enhances cognitive and visual development and function in preterm infants.

DHA has been linked to improved vision and cognition in postnatal feeding studies and has been consistently associated with reduction of early preterm birth in prenatal supplementation trials. However, in one major US randomized double-blind trial (the KUDOS trial), although prenatal DHA supplementation (600 mg/day) substantially reduced early preterm birth and improved visual attention in infancy, no consistent long-term benefits were observed into childhood.

Clinical trials indicate that doses up to 2.7 g/day of DHA are well tolerated, with minimal adverse effects; although higher doses may slightly increase bleeding risks, these effects are rare and not typically clinically significant.

Evidence strength: Moderate for preterm infants (visual acuity, neurodevelopment); inconclusive for healthy term infants and healthy pregnant women; consistent evidence for reducing early preterm birth.

4d. Eye Health

DHA levels are especially high in retina (eye), brain, and sperm cells. The eyes require DHA, making up 30–40% of the fatty acids found in the photoreceptors of the retina, making it critical to eye health.

Dry Eye Disease (DED): A meta-analysis incorporating 19 RCTs and 4,246 DED patients found that patients given omega-3 treatment demonstrated significantly greater improvements in dry eye symptoms, tear break-up time (TBUT), Schirmer test scores, corneal fluorescein staining (CFS), and osmolarity compared to those on placebo. Omega-3 fatty acids consistently alleviated DED symptoms, particularly at high doses, with prolonged intake, and with increased EPA levels. However, the evidence for omega-3 in dry eye is inconsistent overall; the best-quality single RCT found omega-3 supplementation does not improve dry eye symptoms or function.

Age-Related Macular Degeneration (AMD): The AREDS2 trial compared a daily dose of 650 mg EPA and 350 mg DHA to placebo in patients with AMD, and found no significant additional protective effect against AMD progression beyond the established AREDS antioxidant formula. One smaller pilot study (MADEOS) found promising results: participants with dry AMD or Stargardt disease received either the active product (3,660 mg EPA and DHA) or sunflower oil placebo daily for 24 weeks; the active group showed a statistically significant mean gain of 6 ETDRS letters from baseline to week 24 (p=0.003).

Evidence strength: Moderate for dry eye disease (multiple RCTs; some inconsistency); weak-to-moderate for AMD (AREDS2 found no benefit on disease progression; small pilot data are preliminary).

4e. Pain and Inflammation

The only published clinical study that directly used calamari oil as a component of a human intervention for pain management is the following 2023 RCT:

A double-blind, placebo-controlled randomized clinical trial tested a novel combination of full-spectrum hemp oil (phytocannabinoids), calamari oil (omega-3 fatty acids), and broccoli (glucosinolates) to assess whether it could reduce chronic pain and attenuate oxidative stress in adults seeking chiropractic care. Participants with a mean age of 54.8 ± 13.6 years were randomly assigned to consume the multi-ingredient supplement (n=12, intervention plus standard chiropractic care) or placebo (n=13, mineral oil plus standard chiropractic care) daily for 12 weeks.

The intervention softgels contained full-spectrum hemp oil standardized to 15 mg of phytocannabinoids, calamari oil standardized to 230 mg of omega-3 fatty acids (including 130 mg of DHA and 55 mg of EPA), TrueBroc broccoli extract standardized to 5 mg of glucoraphanin, and a carrier oil (extra virgin olive oil).

Self-reported perceived pain, pain interference, and reactive oxygen species (ROS) status in peripheral blood mononuclear cells (PBMCs) were measured at baseline, mid-checkpoint, and post-intervention. The intervention was positively associated with a 52% decrease in pain intensity and several parameters of pain interference including quality of sleep, along with a 29.4% decrease in PBMC ROS.

The authors concluded that supplementation with this novel combination has the potential to manage chronic pain when combined with standard chiropractic care, as suggested by its effects on pain intensity and oxidative stress.

The study has important limitations: very small sample size (n=25 total), multi-ingredient design preventing attribution of effect to calamari oil specifically, and industry affiliation (Standard Process Inc.). In the broader omega-3 literature, research on omega-3 fatty acids found in seafood indicates they may help soothe symptoms of rheumatoid arthritis; participants in some studies have reported shorter periods of morning joint stiffness and reduced joint swelling and pain.

Evidence strength: Very preliminary for calamari oil specifically in pain. Broader omega-3 evidence for inflammatory joint conditions (e.g., rheumatoid arthritis) is moderate.

4f. Blood Pressure and Platelet Aggregation

The fatty acid DHA is higher in squid than in other seafood. DHA has been shown to improve resting heart rate. DHA-rich oils, such as calamari oil, may also help reduce platelet aggregation, particularly in women. These findings derive from studies on DHA-rich marine oils broadly; calamari-oil-specific platelet data are not available in published literature.

5. Body Systems and Health Areas

Based on the established mechanisms and evidence for DHA and EPA, calamari oil is associated with the following body systems and health areas:

• Cardiovascular system: Triglyceride reduction, blood pressure modulation, antithrombotic effects, antiarrhythmic effects.
• Central nervous system and brain: Structural membrane component of neurons; associated with cognitive function, mood regulation, and neuroprotection in neurodegenerative diseases.
• Visual system: DHA constitutes 30–40% of photoreceptor fatty acids; associated with retinal health, dry eye, and AMD.
• Inflammatory pathways: Modulates eicosanoid and cytokine production through competition with arachidonic acid; resolvins and protectins mediate resolution of inflammation.
• Prenatal and pediatric development: Maternal DHA transfer to fetal brain and retina; reduction of early preterm birth risk.
• Musculoskeletal system: Potential for joint inflammation reduction in conditions such as rheumatoid arthritis, extrapolated from fish oil research.

6. Dosage Forms and Reported Dosages

The following dosages appear in the cited sources. These are reported as stated in source materials and should not be interpreted as universal recommendations.

• One commercial calamari oil liquid product delivers 800 mg DHA and 400 mg EPA per 5 mL (one teaspoon) serving, providing 45 calories and 5 g total fat per serving.
• In the 2023 RCT, the calamari oil component was standardized to 230 mg of total omega-3 fatty acids per two softgels per day (including 130 mg DHA and 55 mg EPA).
• In a large dry-eye RCT, the dosage studied was 2,000 mg EPA and 1,000 mg DHA per day for one year (535 participants).
• In the KUDOS prenatal trial, 600 mg/day of DHA was administered from 14.5 weeks of gestation until delivery.
• The FDA has stated that a tolerable upper intake of no more than 3 g/day of EPA and DHA combined, including up to 2 g/day from dietary supplements, is recognized; higher doses are sometimes used to lower triglycerides but carry potential risks including bleeding problems and possible effects on immune function.
• Clinical trials indicate that doses up to 2.7 g/day of DHA are well tolerated, with minimal adverse effects.

7. Safety Considerations and Interactions

Contaminant Profile

One benefit to squid as a raw material is that these animals appear to have a very low threat of mercury contamination. Calamari has a very short life cycle, meaning toxins do not accumulate in them as in many other marine creatures. Many fish with long life cycles are prone to contain harmful metals and toxic deposits such as mercury and PCBs. Although seafood contains varying levels of methyl mercury, omega-3 supplements have not been found to contain this contaminant because it is removed during processing and purification.

Oxidative Stability

Animal studies show that oxidized lipid products can cause harm, and oxidation of trial oils may be responsible for conflicting omega-3 trial literature, including studies of cardiovascular disease prevention. Calamari oil, like all highly unsaturated marine oils, is susceptible to oxidative degradation if improperly stored; the antioxidant additives (e.g., tocopherols, rosemary extract) in commercial formulations are intended to address this.

General Tolerability

Side effects from omega-3 supplements taken in smaller amounts are usually mild, and include an unpleasant taste in the mouth, bad breath, heartburn, nausea, and stomach discomfort. Omega-3 free fatty acids have an excellent safety and tolerability profile; the most common side effects associated with their use in human trials include diarrhea, indigestion, nausea, fishy taste, and belching. The total incidence of gastrointestinal disturbances in Phase 2 and Phase 3 clinical trials has varied between 1.4–4.9%, with a very low rate of study termination.

From a safety perspective, a study commissioned by the Global Organization for EPA and DHA Omega-3s (GOED) found no upper limit for EPA and DHA could be set; EFSA also agreed that it could not determine a tolerable upper limit for these fatty acids.

Anticoagulant and Antiplatelet Interactions

Higher doses of EPA and DHA — those sometimes used to lower triglycerides — could cause bleeding problems and possibly affect immune function. Omega-3 supplementation at high doses may augment the effects of anticoagulant or antiplatelet medications (e.g., warfarin, aspirin, clopidogrel), though the clinical significance of this interaction remains debated. This is a consideration shared by all concentrated marine omega-3 products including calamari oil.

Shellfish/Seafood Allergy

Calamari oil is derived from squid, a mollusk. Individuals with known shellfish or seafood allergies should exercise caution, as cross-reactivity is possible. Some commercial calamari oil supplements are processed in facilities that also handle fish and shellfish.

Sustainability and Manufacturing Quality

The short lifecycle of Argentinian shortfin squid (12–14 months) means the population is constantly reproducing, which bodes well for sustainability; additionally, squid oil can be sourced from pre-existing squid fisheries rather than dedicated catches. Tested supplement categories that include calamari (squid) oil are subject to third-party testing by organizations such as ConsumerLab for content accuracy and contaminant levels.

References

• Carlisle C et al. (2023). Alleviation of Pain, PAIN Interference, and Oxidative Stress by a Novel Combination of Hemp Oil, Calamari Oil, and Broccoli: A Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. PMC10304948
• NIH Office of Dietary Supplements. Omega-3 Fatty Acids — Health Professional Fact Sheet
• NIH Office of Dietary Supplements. Omega-3 Fatty Acids — Consumer Fact Sheet
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• MADEOS pilot study: EPA-rich omega-3 fatty acids supplementation and vision in dry AMD or Stargardt disease. ScienceDirect (2024)
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