It blocks the function of RNA polymerase and of protease which are necessary for virus invasion and replication into host cells. It seems to work for any RNA viruses like SARS CoV2 or Ebola etc.
This medicine is already widely used for osteoporosis in menopausal women and is known to be safe. In addition, it has generics not costly.
It's mechanism to inhibit SARS CoV2 has been understood only with experiments and in vitro studies. We should wait for in vivo results preferably by RCT.
Theoretically, it could work for the mutant strains. In Japan, the vaccination is badly delayed, much less than expected. In Kansai area, B117 strain is surging up at present. It could overwhelm the medical service system. In this context, such a drug as Raloxifene is widely needed.
Of course, it should not be used without regulation. It is used for those with osteoporosis, gynecomastia and so forth. Once it turns out of use for COVID19, it should be manufactured enough to satisfy the necessity.