I don't know about Tamoxin, but I take Evista for prevention of osteoporosis.(I'm 54) Hormone Replacement Therapy does a better job at preventing osteo. but I stayed away from it because of a history of breast cancer in my family, and because I didn't like the sound of the side effects. Evista does not stimulate breast or uterine tissue - maybe that is why her doctor recommended it. Check out both drugs. Evista is the brand name for the drug raloxifene.