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Omega XL - Great Health Works


Omega XL Joint and Muscle Support (distributed by Great Healthworks) is promoted as a “powerful essential fatty acid combination,” providing omega-3 fatty acids and antioxidants to support joint health and post-exercise muscle recovery. However, as discussed below, results of studies investigating the effects of Omega XL for joint and muscle pain have been mixed, and its distributor has been warned by the FDA in the past for making claims that Omega XL can relieve joint pain.

What is in Omega-XL?

Omega XL contains a blend of green-lipped mussel oil extract (PCSO-524, also sold as Lyprinol), olive oil, and vitamin E. Each suggested serving of two capsules contains 300 mg of this blend, but the amount of each ingredient is not listed, as the blend is “proprietary.” ConsumerLab generally warns against “proprietary” blends for this reason (See 7 Red Flags to Watch Out for When Buying Vitamins & Supplements for more information).

Omega XL also doesn’t list the amounts of DHA or EPA (the predominant omega-3 fatty acids found in marine oils shown to have potential health benefits). ConsumerLab tests of Omega XL in 2014 and 2016 found it to contain very little DHA and EPA – just a fraction of what’s typically found in many other fish and marine oil supplements (for details, see our Fish Oil Supplements Review).

What have studies of Omega XL found?

As described below, evidence that Omega XL decreases joint pain is mixed. For reducing muscle pain after exercise, only one study suggests a potential benefit. Studies of Omega XL have been generally small and funded by Pharmalink, the manufacturer of the green-lipped mussel extract in Omega XL. Some of the studies also lacked a placebo-control group, which is needed to prove a benefit. Higher quality research is needed to determine if there is a benefit.


A study in Poland among 50 older men and women (average age 66) with mild to moderate osteoarthritis of the knee or hip found that those who took 8 capsules (1,200 mg) of Omega XL (providing a total of 20.8 mg of EPA and 13.6 mg of DHA per day) for three months showed a slight, but statistically significant reduction in self-reported joint pain (a decrease of about 8.5 points on a scale of 0 to 100) and modest improvement in physical function compared to those who, instead, took 1,200 mg of fish oil (providing 216 mg of EPA and 144 mg of DHA per day)(Zawadzki, Mar Drugs 2013). In contrast, there was no reduction in pain reduction with Omega XL in a study which compared it to olive oil (the placebo control). In that study, 4 capsules of Omega XL were taken once daily for two months, and then 2 capsules daily were taken for three more months (Lau, Progress in Nutrition 2004).

Muscle soreness and exercise recovery

A small study found that daily supplementation with Omega XL modestly reduced muscle damage, pain and inflammation after exercise in young men (average age 22) (Mickleborough, J Int Soc Sports Nutr 2015). In the study, the men took 8 Omega XL capsules per day (providing 400 mg green lipped mussel oil extract (58 mg EPA + 44 mg DHA) and 1.8 mg vitamin E in olive oil) or 8 placebo capsules containing only olive oil daily for one month. On the 26th day of supplementation, the men performed a downhill running exercise designed to induce muscle damage. Those who took the green-lipped mussel combination had significantly less delayed-onset muscle soreness (DOMS) three to four days after exercise as well as lower levels of markers in the blood for muscle damage and inflammation, compared to those who took a placebo.

Other uses

A study found Omega XL/PCSO-524 to reduce the occurrence of wheezing in adults with asthma (Emelyanov, Eur Respir J 2002), while a study in children with asthma found no benefit compared to placebo (Lello, Inter J of Asthma, Allergy and Immunol 2012).

Any promotion of Omega XL for heart health appears to be based on the fact that it contains omega-3 fatty acids, not published clinical studies, although, as noted, it contains a scant amount of omega-3s.

Omega XL Safety and Side Effects

In the studies above, side effects were not evaluated or reported. However, as discussed in our Fish Oil Supplements Review, gastrointestinal side effects such as nausea, burping, and diarrhea can occur when taking fish or other marine oil supplements.

When taken at dosages used in the studies above, no significant changes in blood pressure, red and white blood cell counts, hemoglobin, hematocrit, platelet count, or liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were reported in studies that assessed these measures.

The Omega XL website states it is free of “allergenic levels of shellfish protein,” and according to the Omega XL website, the “proprietary extraction process” used to make this extract removes these proteins. However, to be safe, it may be best for people with shellfish allergies to avoid Omega XL or consult with a physician before using. The Omega XL website advises: “If you have an allergy, it is best to introduce any new supplement into your diet under the supervision of a healthcare provider.”

Green-lipped mussel extract should not be taken by women who are pregnant or nursing, as an animal study suggests it may interfere with fetal development (Miller, N Z Med J 1984).

For details about other potential side effects and drug interactions when taking omega-3 fatty acids such as EPA and DHA from fish or marine oils, see the Concerns and Cautions section of our Fish Oil Supplements Review.


Omega XL Joint Support is expensive. One bottle of Omega XL Joint Support containing 60 soft gel capsules costs $48.99, which works out to 82 cents per capsule. If taken as suggested on the label, at two capsules twice daily (four capsules total), the daily cost is $3.28 and the monthly cost is nearly $100.

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