Fourteen of them were identified from the oil of seeds of Astragalus complanatus as heptenoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, octadecenoic acid, octadecanoic acid, octadecadienoic acid, linolenic acid, eicosanoic acid, eicosenoic acid and docosanoic acid, etc. The chemical constituent cycloastragenol (also called TAT2) is being studied to help combat HIV, as well as infections associated with chronic diseases or aging. However, the National Institutes of Health states: "The evidence for using astragalus for any health condition is limited. High-quality clinical trials (studies in people) are generally lacking. There is some preliminary evidence to suggest that astragalus, either alone or in combination with other herbs, may have potential benefits for the immune system, heart, and liver, and as an adjunctive therapy for cancer".