No you cannot stay on it indefinately. Neither one. Nolvadex originally used as a breast cancer treatment was given to women in dosages moderate to high over long periods of time. They eventually after years of use had many problems. Liver damage, other forms of cancer, eye damage(ocular nerve is what i think its called), dr.d even knew a women that lost her hair and teeth from extended use over years period of time. Not safe.
Do some more research.