Krill oil is high in the same omega-3 fatty acids (EPA and DHA) as fish oil. Unlike fish oil, however, the fatty acids in krill oil are mainly in the form of phospholipids that are readily absorbed and used.⁴ Krill oil has been shown to lower high triglyceride levels in clinical trials, but trials examining the effects of krill oil, and fish omega-3 fatty acids more generally, on cholesterol levels have yielded mixed results, with some trials indicating neutral or negative effects and others noting beneficial effects.^5,4 A meta-analysis of results from seven randomized controlled trials with a total of 662 participants showed krill oil, at doses ranging from 0.5–4 grams per day, lowered both triglyceride and LDL-cholesterol levels, particularly when used for 12 weeks or longer.⁷ However, an analysis comparing data from 64 randomized controlled trials found krill oil raised HDL-cholesterol levels without affecting LDL- or total cholesterol levels, and found no significant difference between the effects of krill oil and fish oil on cholesterol levels.⁴

In a double-blind study of people with elevated blood levels of cholesterol and triglycerides, supplementation with 2 to 3 grams per day of krill oil from Antarctic krill (a zooplankton crustacean) for three months decreased levels of triglycerides. However, 1 to 1.5 grams per day was not effective. Krill oil was significantly more effective than either a placebo or small amounts of regular fish oil containing 900 mg per day of omega-3 fatty acids.⁷

In a double-blind trial, women with PMS took 2 grams of either krill oil from Antarctic krill (a zooplankton crustacean) or fish oil for one month, followed by two months in which the women took their supplement beginning eight days prior to menstruation and continuing for two days after the start of menstruation. While abdominal pain symptoms were similarly reduced by either oil, those taking krill oil reported using fewer pain relievers for menstrual pain.⁸

Krill oil from Antarctic krill (a zooplankton crustacean) has been shown in a double-blind trial to be an effective treatment for premenstrual syndrome. Krill oil was significantly more effective than similar amounts of regular fish oil in relieving emotional symptoms and breast tenderness related to premenstrual syndrome. The amount of krill oil used in this study was 2 grams per day for the first month. In the second and third months the women took 2 grams per day beginning eight days prior to menstruation and continuing for two days after the start of menstruation.⁹

In a double-blind trial, women with PMS took 2 grams of either krill oil from Antarctic krill (a zooplankton crustacean) or fish oil for one month, followed by two months in which the women took their supplement beginning eight days prior to menstruation and continuing for two days after the start of menstruation. While abdominal pain symptoms were similarly reduced by either oil, those taking krill oil reported using fewer pain relievers for menstrual pain.¹⁰

Krill oil from Antarctic krill (a zooplankton crustacean) has been shown in a double-blind trial to be an effective treatment for premenstrual syndrome. Krill oil was significantly more effective than similar amounts of regular fish oil in relieving emotional symptoms and breast tenderness related to premenstrual syndrome. The amount of krill oil used in this study was 2 grams per day for the first month. In the second and third months the women took 2 grams per day beginning eight days prior to menstruation and continuing for two days after the start of menstruation.¹¹

In a double-blind study, people with high levels of C-reactive protein (CRP), an indicator of systemic inflammation in the body, most of whom also had osteoarthritis, were given 300 mg each morning of krill oil from Antarctic krill (a zooplankton crustacean) or a placebo. After one month those taking krill oil had significantly greater reduction in arthritis severity based on a questionnaire focusing on joint pain, stiffness, and loss of function related to osteoarthritis of the knee and hip. Use of pain-relief medication was also reduced compared to those taking placebo.¹²