DHA (docosahexaenoic acid) is a long chain omega-3 fatty acid that is produced from EPA. It is one of the constituents of fish oil. It is the omega-3 fatty acid that is found in brain and nerve tissue. Recent research suggests that infant formula should be fortified with DHA. Supplements may have a beneficial effect on some behavioral and neurological problems, but more research needs to be done. Because of their effect on blood clotting, you should exercise care when taking fish oil and any anticoagulant drugs, aspirin, or ginkgo, which all affect blood clotting.