Although zidovudine (AZT) prolongs life in certain AIDS patients, it is not a cure for AIDS and it also has toxic effects in many patients. Therefore, it is necessary to test other drugs in HIV-infected patients. AL-721 is a mixture of lipids (fats) extracted from egg yolks. Laboratory tests suggest that it might inhibit the infectivity of the HIV. AL-721 has been tried so far in a few patients for short periods of time and has been found to be well tolerated.