There are many fish oil dietary supplements on the market. Evidence suggests that marine based omega-3 dietary supplements are able to reduce cardiovascular disease, and premature death. These effects may not carry over in other populations such as people who have diabetes. The ingredients of dietary supplements are not as carefully controlled as prescription products and have not been fixed and tested in clinical trials, as prescription drugs have, and the prescription forms are more concentrated, requiring fewer capsules to be taken and increasing the likelihood of compliance.