IngredientsKrill oil is a marine lipid extract derived primarily from Antarctic krill (Euphausia superba), a small, shrimp-like crustacean of the order Euphausiaceae. Euphausia superba are the most commercially important species of krill; they live in dense shoals, principally in Antarctic waters, and feed mainly on phytoplankton, making them a critical member of the worldwide food chain. Krill are small, pelagic crustaceans also found in abundance in temperate and subarctic waters, including the North Atlantic (Meganyctiphanes norvegica), North Pacific (Euphausia pacifica), and the Antarctic Ocean (Euphausia superba). However, commercial supplement production is dominated by E. superba as the source species.
Antarctic krill is one of the most abundant multi-cellular animal species on earth, with one of the largest biomasses estimated at around 500 million metric tons. These small pinkish-red transparent creatures move in huge swarms feeding on microscopic algae, providing them with a diet rich in omega-3 fatty acids — the result of which is that krill oil is a pure, natural source of EPA and DHA omega-3 fatty acids.
The product is universally known as krill oil (abbreviated KO). The primary species name is Euphausia superba Dana, 1852 (family Euphausiidae). In commercial and research contexts it may appear as Antarctic krill oil, and branded preparations include Neptune Krill Oil (NKO®) and Superba™ Krill Oil, among others.
Krill oil is commercially available primarily as softgel capsules containing the liquid oil, though liquid forms and novel encapsulated formats exist. Advancements in encapsulation technologies aim to optimize delivery and efficacy of krill oil supplements, with four novel encapsulation methods under investigation: micro/nanoemulsions, microcapsules, liposomes, and nanostructured lipid carriers.
Seven different extraction solvents — ethanol, isopropanol, acetone, ethyl acetate, isohexane, n-hexane, and subcritical butane — have been investigated for their effects on lipid yield and quality. Phospholipid (PL) content, fatty acid composition, and minor components including sterols, astaxanthin, vitamin A, and tocopherols are all analyzed in extracted krill oil. Ethanol and isopropanol lead to comparatively higher lipid yields (16.33% and 14.52%, respectively) and PL contents (39.2% and 38.7%, respectively). Krill oil extracted with acetone has the lowest PL content (20.63%) but contains more astaxanthin (206.74 mg/kg), vitamin A (27.84 mg/100 g), and sterols (39.00 mg/g). The common industrial methods for obtaining krill oil are extraction using organic solvents and supercritical carbon dioxide (SC-CO₂).
Krill as a food source has a documented history in East Asian culinary traditions. Despite their small size (2 g maximum), Euphausia superba are fished to produce tail meat, which is frozen or pickled and in high demand in Japan, Korea, Russia, and former Soviet Union countries. The Japanese industry produces boiled, frozen krill and peeled tail meat; other uses include krill pastes or processed krill as food additives.
Krill as a source of extracted oil, however, has no deep traditional medicinal history in the sense of plant-based ethnomedicinal traditions. The modern commercial and scientific interest in krill oil is a late-twentieth-century development. Krill fishing in the Antarctic began in the 1960s by the Soviet Union, starting as an experiment and becoming more permanent a decade later; Japan followed in 1975 and harvests peaked in the early 1980s when other nations joined, but the market was always dominated by the Soviet Union. After the Soviet Union's collapse in 1991, the krill fishery diminished. It was not until 2003 that a new major player emerged: Aker BioMarine from Norway.
Krill processing by-product and krill unsuited for producing tail meat were initially used to make krill meal, krill hydrolysate, and krill oil. The refined, phospholipid-rich krill oil supplement as known today entered commercial markets primarily in the early 2000s. The first clinical study on krill oil commenced in 2003, marking the onset of research into its effects on human health, particularly cardiovascular health, inflammation, and cholesterol-related issues. Of the 376 krill-related patents registered worldwide until 2002, 17% related to medical uses, most of which were registered after 1988.
Krill oil, derived from Antarctic krill (Euphausia superba), is rich in omega-3 fatty acids, phospholipids, and astaxanthin. The predominant omega-3 fatty acids are eicosapentaenoic acid (EPA; C20:5 n-3) and docosahexaenoic acid (DHA; C22:6 n-3). Roughly 40% of krill oil's overall fatty acids are EPA (C20:5) and DHA (C22:6).
The defining structural feature of krill oil — distinguishing it from conventional fish oil — is that its EPA and DHA are largely bound to phospholipids rather than triglycerides. The overall phospholipid content of krill oil is high; in krill oil, EPA and DHA are bound to phospholipids, mainly phosphatidylcholine. Krill oil presents a distinctive fat profile, rich in lipid classes, with phospholipids comprising a significant portion (38.93–79.99%) with high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are the most abundant types of phospholipids in krill oil, ranging from 44.58–99.80% of total PLs.
In addition to omega-3 fatty acids, krill oil contains phospholipid-derived fatty acids, choline, and astaxanthin. The astaxanthin content gives krill oil its characteristic red color and provides antioxidant benefits. Astaxanthin, the primary carotenoid in krill and certain other marine organisms, exhibits potent antioxidant properties; its antioxidant potency has been described as ten times stronger than zeaxanthin, lutein, canthaxanthin, and β-carotene, and 100 times superior to alpha-tocopherol. The astaxanthin content in krill oil varies from 4 to 500 mg/100 g, affected by factors such as extraction technique and analytical method.
Due to their rich diet of algae, krill oil is naturally rich in phospholipids (phosphatidylcholine), omega-3 EPA and DHA, and choline. Choline is a precursor for acetylcholine, an important neurotransmitter involved in muscle control, circadian rhythm, memory, and many other neuronal functions.
Krill oil also includes several minor bioactive components such as tocopherols, sterols, flavonoids, and vitamin A. Due to its complex composition, which contains structurally different chemical compounds such as PUFAs, flavonoids, astaxanthin, and vitamins, the pharmacological effects of krill oil are ascribable to multiple mechanisms of action.
Krill oil is characterized by a high quantity of n-3 PUFAs (mainly EPA and DHA), which are natural ligands for peroxisome proliferator-activated receptors (PPARs) responsible for PPAR activation. These transcription factors play a fundamental role in regulating cell and tissue behavior in response to different stimuli. PPAR activation is implicated in lipid metabolism, inflammation modulation, and glucose homeostasis.
Unlike fish oil, whose omega-3s are incorporated into triglycerides, the lipid composition of krill oil is characterized by a high concentration of phospholipids carrying EPA and DHA. Omega-3 fatty acids in this form are readily incorporated into tissues in a more effective and efficient manner compared to triglycerides and ethyl esters. Phospholipid-bound EPA and DHA uptake into cellular membranes is believed to be far more efficient than triacylglyceride-bound EPA and DHA, since liver conversion of triacylglycerides is itself inefficient and because phospholipid-bound EPA and DHA can be transported into the bloodstream via the lymphatic system, thus avoiding liver breakdown.
Krill oil is enriched with long-chain n-3 PUFAs, especially EPA and DHA, and the potent antioxidant astaxanthin, contributing to its therapeutic properties. The possible underlying mechanisms of krill oil's health benefits include anti-inflammatory and antioxidant actions, maintaining intestinal barrier functions, and modulating gut microbiota.
In preclinical models, krill oil treatment was associated with decreased plasma levels of thromboxane B2, P-selectin, endothelin-1, β-thromboglobulin, platelet factor 4, serotonin, TNF-α, IL-1β, and IL-6, while inducing prostacyclin I2 and plasminogen. In vitro, krill oil decreased the adhesion of THP-1 monocytes to human endothelial cells stimulated by TNF-α via eNOS activation and NO production, and inhibited the expression of TNF-α-induced adhesion molecules such as ICAM-1 and VCAM-1 by suppressing the NF-κB signaling pathway.
The question of whether krill oil's phospholipid-bound EPA and DHA is more bioavailable than the triglyceride form in fish oil is one of the most studied aspects of krill oil research.
Key human study: In a double-blinded crossover trial, researchers compared the uptake of three EPA+DHA formulations derived from fish oil (re-esterified triacylglycerides and ethyl esters) and krill oil (mainly phospholipid). Twelve healthy young men (mean age 31 years) were randomized to 1,680 mg EPA+DHA given as one of the three formulations, with fatty acid levels analyzed in plasma at multiple timepoints up to 72 hours after ingestion. The highest incorporation of EPA+DHA into plasma phospholipids was provoked by krill oil (mean AUC₀–72h: 80.03 ± 34.71 %·h), followed by fish oil rTAG (59.78 ± 36.75 %·h) and ethyl ester (47.53 ± 38.42 %·h). However, due to high standard deviation values, there were no significant differences for DHA and the sum of EPA+DHA levels between the three treatments.
Network meta-analysis (2024): A network meta-analysis incorporating data from studies published between 2003 and 2023, sourced from five databases including PubMed and Cochrane CENTRAL, found that out of 26 high-quality studies, results reveal superior bioavailability of krill oil compared to fish oil overall. Specifically, fish oil above 3,000 mg, re-esterified triacylglycerol or ethyl ester formulations (100–2,900 mg), and krill oil (100–1,900 mg) all significantly enhanced the Omega-3 Index; at lower dosages (under 2,000 mg), krill oil shows superior Omega-3 absorption compared to fish oil. This finding should be interpreted with caution due to high heterogeneity and limited statistical significance in some comparisons.
Evidence strength: Moderate. Several human studies demonstrate numerically higher short-term plasma EPA levels with krill oil at lower doses, but many individual comparisons do not reach statistical significance and long-term data are limited. The phospholipid bioavailability advantage is biologically plausible and supported by multiple, though not all, studies.
Systematic review and meta-analysis (Oxford Academic / Nutrition Reviews, 2017): A meta-analysis of data from 7 eligible randomized controlled trials (14 treatment arms) with 662 participants showed a significant reduction in plasma concentrations of LDL cholesterol (weighted mean difference [WMD], −15.52 mg/dL; 95% CI, −28.43 to −2.61; P = 0.018) and triglycerides (WMD, −14.03 mg/dL; 95% CI, −21.38 to −6.67; P < 0.001) following krill oil supplementation. A significant elevation in plasma HDL cholesterol was also observed (WMD, 6.65 mg/dL; 95% CI, 2.30 to 10.99; P = 0.003), while a reduction in total cholesterol did not reach statistical significance (WMD, −7.50 mg/dL; 95% CI, −17.94 to 2.93; P = 0.159). The authors noted that additional clinical studies with more participants are needed to assess the impact of krill oil supplementation on other indices of cardiometabolic risk and on the risk of cardiovascular outcomes.
Crossover RCT vs. ethyl ester omega-3: A double-blind, randomized clinical trial was carried out in 25 moderately hypertriglyceridemic subjects (TG = 150–500 mg/dL); after a 4-week run-in, participants were allocated to treatment with omega-3 ethyl ester PUFAs 1,000 mg twice daily versus krill oil 500 mg twice daily. Although both PUFA sources improved TG plasma levels, esterified omega-3 PUFAs were more efficacious than krill oil for TG reduction (p < 0.05); however, only krill oil treatment significantly improved HDL cholesterol and apolipoprotein AI levels compared to both baseline and end-of-treatment with esterified omega-3 PUFAs. Both treatments significantly reduced high-sensitivity C-reactive protein (hs-CRP) from baseline (p < 0.05), but krill oil improved it more efficaciously than esterified omega-3 PUFAs, with krill oil achieving comparable lipid-lowering effects to a 4-fold higher dose of purified omega-3 ethyl esters.
Evidence strength: Moderate for LDL and triglyceride reduction and HDL elevation, based on pooled RCT data. Absolute effect sizes are modest. The evidence does not yet extend to hard cardiovascular endpoints (e.g., myocardial infarction, stroke). The body of trials is generally small and of short duration.
RCT in arthritis/cardiovascular patients: Using a randomized, double-blind, placebo-controlled study protocol, 90 patients were recruited with either confirmed cardiovascular disease and/or rheumatoid arthritis and/or osteoarthritis and with elevated CRP levels (>1.0 mg/dL) upon three consecutive weekly blood analyses prior to initiation of oral treatment. Group A received Neptune Krill Oil (300 mg daily) and group B received a placebo. CRP and WOMAC osteoarthritis scores were measured at baseline and days 7, 14, and 30. After seven days of treatment, krill oil reduced CRP by 19.3% compared to an increase of 15.7% in the placebo group (p = 0.049). After 14 and 30 days of treatment, krill oil further decreased CRP by 29.7% and 30.9%, respectively (p < 0.001).
In the same trial, Neptune Krill Oil also reduced scores of arthritis pain, stiffness, and functional impairment.
Evidence strength: Promising based on individual RCTs, but the evidence base is limited in number of trials. Larger, independent replications are warranted before definitive conclusions can be drawn.
Meta-analysis (Inflammopharmacology, 2026): Six RCTs with 971 participants were included in a meta-analysis evaluating krill oil supplementation in patients with knee osteoarthritis (KOA). Krill oil supplementation significantly improved pain and physical function (WOMAC scores at week 4), with moderate effects observed on stiffness.
Supplementation with a krill oil preparation (300 mg/day) reduced CRP levels and moderated the severity of several symptoms, such as pain, joint stiffness, and other symptoms, in controlled trials.
Evidence strength: Moderate. Multiple RCTs consistently show short-term symptom improvement. Longer-term structural effects (e.g., cartilage preservation) remain under-studied.
RCT (Neptune Krill Oil, University of Montreal): Researchers from the University of Montreal conducted a clinical study evaluating two types of omega-3 supplements — krill oil and fish oil — on the management of PMS and dysmenorrhea, recruiting 70 patients diagnosed with PMS who were assigned to receive equal dosages of either krill oil or fish oil daily for 90 days. The results showed that krill oil was more effective in reducing the symptoms of dysmenorrhea and PMS compared to fish oil.
A total of 70 women were given two 1 g softgels of Neptune Krill Oil or fish oil daily for 90 days. The NKO group experienced improvement in physical and emotional symptoms of PMS and saw a notable reduction in the use of analgesics (pain medications). In this blinded, randomized clinical trial, krill oil supplementation was found to be effective in reducing PMS symptoms including joint pain, abdominal pain, swelling, and breast tenderness.
Evidence strength: Limited. The evidence currently rests on a single published clinical trial (Sampalis et al., 2003). Independent replication is needed.
RCT in elderly males (2013): Krill oil, rich in n-3 PUFAs incorporated in phosphatidylcholine, has been reported to have effects on physiological function; however, few psychophysiological studies have been published. In a randomized, double-blind, parallel-group comparative study, 45 healthy elderly males aged 61–72 years were assigned to receive 12 weeks of treatment with medium-chain triglycerides (placebo), krill oil (rich in n-3 PUFAs in phosphatidylcholine), or sardine oil (rich in n-3 PUFAs in triglycerides). During working memory tasks, changes in oxyhemoglobin concentrations in the krill oil and sardine oil groups were significantly greater than those in the medium-chain triglyceride group at week 12. The differential value for P300 latency in the krill oil group was significantly lower than that in the medium-chain triglyceride group at week 12.
Adolescent RCT (Food2Learn trial): A double-blind, randomized, placebo-controlled supplementation trial with repeated measurements (baseline, three months, six months, and 12 months) investigated the effect of one year of krill oil supplementation on cognitive performance in adolescents with a low Omega-3 Index (O3I ≤ 5%). A total of 267 participants were randomized to 400 mg EPA+DHA per day in Cohort I or 800 mg EPA+DHA per day in Cohort II, or placebo.
Animal/preclinical data: Krill oil has been described as having the potential to ameliorate the detrimental consequences of a high-fat diet on the aging brain, and researchers have hypothesized that dietary krill oil supplementation could counteract the effects of cognitive aging and a high-fat diet on spatial learning, neuroinflammation, neurogenesis, and synaptic density in the cortex and hippocampus. These findings are from animal models and have not been directly confirmed in human trials.
Evidence strength: Preliminary. Human data show neurophysiological changes associated with krill oil, but the clinical significance and consistency across populations remain to be established. Animal model data are more extensive but not directly translatable.
Recent experimental and clinical studies suggest that krill oil has potential therapeutic benefits in preventing the development of a range of chronic conditions, including inflammatory bowel disease. Krill oil is enriched with long-chain n-3 PUFAs and the potent antioxidant astaxanthin; the possible underlying mechanisms of its benefits include anti-inflammatory and antioxidant actions, maintaining intestinal barrier functions, and modulating gut microbiota.
Evidence strength: Largely preclinical (in vivo and in vitro). Human clinical trial data specific to IBD are lacking. The mechanistic basis is plausible based on the known anti-inflammatory properties of EPA/DHA.
Research indicates that supplementing with krill oil positively affects markers of inflammation, oxidative stress, muscle function, glucose metabolism, and lipid profiles. Krill oil induced favorable changes in fatty acid composition, adipose tissue morphology, and adipokine levels, contributing to reduced inflammation and improved metabolic parameters. Most of this evidence, however, derives from preclinical (animal) studies, and specific human RCT data on glucose metabolism remain limited.
Krill oil is sold predominantly as oral softgel capsules. Below are dosages as reported in clinical studies and research sources:
No universally agreed therapeutic dose has been established through regulatory pharmacopoeia or major health authority monographs. Doses studied clinically span a wide range depending on the indication and outcome of interest.
Similar to fish oil, krill oil is considered generally safe for adults. Other potential side effects of omega-3 supplements are usually mild and include unpleasant taste, bad breath, heartburn, and gastrointestinal discomforts, such as nausea and diarrhea. Unlike fish oil-based products, krill oil consumption does not typically produce the fishy burp-back phenomenon reported with fish oil.
Krill oil, like other omega-3 supplements, has a mild antiplatelet effect that can increase the risk of bruising and bleeding when combined with anticoagulants or antiplatelets. The omega-3s in krill oil can reduce platelet aggregation by replacing other fatty acids in platelet membranes, thereby interfering with the clotting process.
Krill oil may slow blood clotting; taking krill oil along with medications that also slow clotting might increase the chances of bruising and bleeding. Medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac, ibuprofen, naproxen, dalteparin, enoxaparin, heparin, and warfarin.
However, the clinical significance of this interaction appears modest at typical supplement doses. In a retrospective analysis of 573 warfarin users (145 in the fish and krill oil supplement group, 428 in the control group), it was found that fish and krill oils did not significantly alter warfarin time in therapeutic range or bleeding incidence. Omega-3 supplementation with fish and krill oil does not appear to significantly affect long-term warfarin control and bleeding and thromboembolic events when consumed concurrently in patients managed at an anticoagulation clinic.
Because krill oil can slow blood clotting, there is concern that it might increase the risk of bleeding during and after surgery. Cessation of krill oil at least 2 weeks before a scheduled surgery has been recommended in clinical guidance.
Krill oil might lower blood sugar; since diabetes medications are also used to lower blood sugar, taking krill oil along with diabetes medications might cause blood sugar to go too low.
Similar risks of enhanced antiplatelet activity might apply to taking krill oil concurrently with supplements such as ginkgo biloba, garlic, and ginger. Taking omega-3 supplements may increase the risk of bleeding when combined with blood thinners, full-dose aspirin, high-dose non-steroidal anti-inflammatory drugs (NSAIDs), or certain supplements such as St. John's Wort.
The absorption of krill oil may also be affected by certain weight loss drugs. In particular, orlistat (which inhibits fat absorption) has been noted as a potential interaction, classified as a minor interaction.
Individuals with shellfish allergies should avoid krill oil, as krill is a crustacean and can cause allergic reactions. The U.S. Food and Drug Administration (FDA) recommends caution in people who are allergic to seafood.
There is a slight risk of developing abnormal heart rhythms with omega-3 supplements; this risk applies broadly to the omega-3 supplement class, including krill oil.
An analysis of 47 commercial fish and krill oils found that the actual percentage of EPA and DHA relative to label claims ranged from 62% to 184%, and 70% of the supplements tested did not contain the stated amount of EPA or DHA. Thus, patients who believe they are taking a stated dose may actually be ingesting only a fraction of that amount or significantly more.
Health conditions that Krill oil may help support.
Krill oil is a dietary source of astaxanthin, a carotenoid antioxidant that quenches lipid peroxyl radicals within cell membranes and scavenges aqueous radicals at membrane interfaces. Human RCTs have shown krill oil raises the omega-3 index and reduces markers of oxidative stress. Astaxanthin in krill oil has documented antioxidant activity superior to many common antioxidants in vitro.
The same 2025 RCT in MDD patients that showed antidepressant effects also found that anxiety and distress scores on the DASS-21 scale decreased significantly in the krill oil group compared to baseline (p<0.001). Animal data in senescence-accelerated mice show krill oil reduces anxiety-like behavior. Evidence is preliminary and largely co-reported with depression outcomes.
Krill oil provides EPA and DHA in phospholipid form (superior bioavailability compared to triglyceride form in fish oil) plus astaxanthin, an antioxidant that protects these fatty acids. Clinical studies show krill oil reduces triglycerides, improves endothelial function, and reduces inflammatory markers. Multiple RCTs confirm its cardiovascular lipid-modifying benefits.
Krill oil from Antarctic krill (Euphausia superba) provides omega-3 fatty acids (EPA and DHA) in phospholipid form, along with astaxanthin. The Arthritis Foundation identifies krill oil as having potential to reduce body inflammation. Preclinical OA models show cartilage protection, and it is the subject of an ongoing Australian multicenter RCT (KARAOKE trial) specifically for knee OA with synovitis.
An open-label pilot trial by Aker BioMarine in 18 boys (ages 7–11) with ADHD found improvements in EEG scores after 13 weeks of krill oil supplementation. Broader omega-3 PUFA RCTs show modest improvements in ADHD symptoms in children; krill-specific RCT evidence is limited but supported by DHA's documented role in prefrontal cortex function.
A 2025 RCT in MDD adults found krill oil supplementation significantly reduced HbA1c compared to baseline, an effect not observed with fish oil or placebo. An independent RCT also reported a significant decrease in fasting blood glucose in the krill group. A 2023 updated meta-analysis of cardiovascular RCTs found no significant overall effect on blood glucose across trials, indicating results are mixed.
Krill oil provides omega-3 fatty acids (EPA and DHA) in phospholipid form with superior bioavailability compared to fish oil, plus the antioxidant astaxanthin. A randomized, double-blind, placebo-controlled trial (Deutsch, J Am Coll Nutr 2007, n=90) found krill oil 300 mg/day for 30 days significantly reduced WOMAC pain, stiffness, and functional impairment scores and serum CRP versus placebo in OA and RA patients. A 2022 network meta-analysis identified krill oil as improving the joint microenvironment in knee OA.
Krill oil provides EPA and DHA in phospholipid form, which may enhance bioavailability versus fish oil triglycerides. It suppresses total cholesterol, LDL-C, and HMG-CoA reductase activity in animal studies, and is recognized in dyslipidemia supplement reviews for triglyceride and total cholesterol modulation.
Krill oil contains EPA and DHA bound to phospholipids, plus the antioxidant astaxanthin, giving it documented anti-inflammatory activity. Multiple randomized controlled trials and a 2026 meta-analysis confirm reductions in CRP and pro-inflammatory cytokines. Evidence is strongest for conditions driven by chronic low-grade inflammation (osteoarthritis, cardiovascular risk, IBD), though effect sizes are modest and larger confirmatory trials are still needed.
Krill oil provides phospholipid-bound EPA and DHA omega-3 fatty acids with superior bioavailability compared to fish oil triglycerides, plus astaxanthin. Clinical trials show krill oil reduces chronic low-back pain and OA joint pain. Phospholipid omega-3s reduce inflammatory markers (CRP, IL-6) relevant to chronic pain.
A 2013 RCT (Konagai et al.; n=45 healthy elderly) found krill oil improved working memory and prefrontal cortex activation versus placebo. No dedicated human clinical trials testing krill oil for prevention of cognitive decline or dementia have been conducted. Multiple animal models confirm krill oil attenuates Alzheimer's-like pathology and aging-related cognitive impairment.
A 2025 double-blind RCT (n=57 MDD adults, 8 weeks) found krill oil (520 mg EPA+DHA/day) significantly reduced Hamilton Depression Rating Scale scores versus placebo (p<0.001). Animal studies in chronic stress models show krill oil preserves brain DHA and attenuates depression-like behavior. Evidence parallels broader omega-3 PUFA literature but is limited in volume of krill-specific human trials.
A double-blind, placebo-controlled RCT (Deinema et al., Ophthalmology 2017; n=60) showed krill oil supplementation for 90 days significantly reduced tear osmolarity and OSDI symptom scores versus placebo, with the krill oil group uniquely achieving significant reductions in the proinflammatory cytokine IL-17A. These benefits were superior to or additive versus fish oil on symptom measures.
Two 2024 randomized, double-blind, placebo-controlled pilot studies (Handeland et al., PMID 39169540; n=51 and n=50 healthy adults) found that 1 g and 2 g of krill oil/day for 12 weeks produced significant, dose-dependent reductions in transepidermal water loss (TEWL) and improvements in skin hydration compared to placebo. Effects correlated linearly with increases in the omega-3 index.
Krill oil provides EPA and DHA in phospholipid form alongside astaxanthin, with anti-inflammatory properties relevant to joint health. A 6-month multicenter double-blind placebo-controlled RCT (PMC9437987) found krill oil resulted in modest but significant improvements in knee OA pain, stiffness, and physical function. A 2025 network meta-analysis (39 RCTs, 4,599 KOA patients) ranked krill oil among supplements showing potential for function improvement.
Krill oil provides EPA and DHA in phospholipid form for superior brain bioavailability compared to fish oil triglycerides, plus the potent antioxidant astaxanthin. Multiple RCTs demonstrate krill oil improves omega-3 index, reduces inflammatory markers, and supports cardiovascular and cognitive health in aging adults with superior dose efficiency.
A 2017 meta-analysis of 7 RCTs (n=662) found krill oil significantly reduced LDL cholesterol (−15.52 mg/dL) and triglycerides (−14.03 mg/dL) and raised HDL cholesterol (+6.65 mg/dL). A 2023 updated meta-analysis of 14 RCTs (n=1,458) confirmed significant reductions in total cholesterol, LDL, and triglycerides. Blood pressure was not significantly affected across trials.
In vitro studies show krill oil dose-dependently reduces LPS-induced IL-1β and TNFα in human macrophages via NF-κB pathway suppression. Animal UC models show krill oil attenuates colonic inflammation and oxidative stress. A 2024 PMC systematic review concluded krill oil has potential therapeutic benefits in IBD prevention, though no human clinical trials in IBD patients have been published.
An RCT (Konagai et al., Clinical Interventions in Aging 2013; n=45 healthy elderly) found krill oil supplementation improved working memory performance versus sardine oil and placebo, with significant prefrontal oxyhemoglobin changes detected by fNIRS. Multiple animal models show krill oil attenuates memory impairment in aging and Alzheimer's models.
A double-blind RCT (Sampalis et al., 2003; n=70 women with PMS/dysmenorrhea) found Neptune Krill Oil (2 g/day for 3 months) significantly reduced dysmenorrhea pain and analgesic use, with effects superior to fish oil. The proposed mechanism is EPA-mediated reduction of pro-inflammatory prostaglandins that cause uterine cramping.
Krill oil, rich in phospholipid-bound EPA and DHA plus the antioxidant astaxanthin, has been studied in clinical trials and meta-analyses for its effects on dyslipidemia—a core component of metabolic syndrome. A 2017 meta-analysis of 7 RCTs (662 participants) found significant reductions in LDL-C and triglycerides and a significant increase in HDL-C. However, a 2023 updated systematic review found no clinically meaningful effect of krill oil on blood pressure, fasting glucose, insulin resistance, BMI, or inflammatory markers, limiting its demonstrated benefit to the lipid profile component of metabolic syndrome rather than the syndrome as a whole.
Krill oil provides EPA and DHA in phospholipid form (with astaxanthin) and has been studied for supporting exercise recovery in athletes. An observational study cited in a 2022 PMC narrative review found krill oil supplementation supported HS-Omega-3 index recovery and post-exercise free radical scavenging after high-power training.
The Sampalis et al. (2003) double-blind RCT (n=70 women) found Neptune Krill Oil significantly improved both physical and emotional symptoms of PMS versus baseline, with improvements greater than the fish oil comparator. A 3-month pilot with 29 women using a krill oil-based formulation also showed significant reductions in PMS symptoms.
Krill oil provides omega-3 fatty acids (EPA and DHA) in phospholipid form with higher bioavailability than standard fish oil, plus astaxanthin, an antioxidant. Animal studies show it reduces arthritis scores in collagen-induced arthritis models, and a clinical study (Deutsch) found it reduced CRP and subjective symptoms in RA and OA patients.
Two 2024 randomized double-blind placebo-controlled pilot studies (Handeland et al., PMID 39169540; n=51 and n=50) found krill oil supplementation at 1–2 g/day for 12 weeks produced dose-dependent improvements in skin elasticity. Preclinical studies show krill oil upregulates collagen and hyaluronic acid synthesis genes in mouse skin.
Krill oil delivers EPA and DHA in phospholipid form, which may offer enhanced bioavailability compared to standard fish oil. Clinical studies and a systematic review/meta-analysis support its ability to reduce plasma triglycerides in humans, consistent with the known omega-3 triglyceride-lowering mechanism.
Body systems that Krill oil may help support.
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