Our new formula contains 400 mg EPA and 300 mg DHA—the long-chain omega-3's that have been shown to support a healthy heart, normal joint flexibility and much more.* The ethyl ester form of fish oil is a more concentrated source of EPA and DHA and also repeats less than other forms of fish oil. All of our omega fish oil products are derived from deep sea, cold-water fish and are independently tested for PCB's, heavy metals and other contaminants, to ensure purity.