There are some things about Nolva that freak me out (probably brought up before):
Carcinogenesis: A conventional carcinogenesis study in rats (doses of 5,20, and 35 mg/kg/day for up to 2 years) revealed hepatocellular carcinoma at all doses, and the incidence of these tumors was significantly greater among rats given 20 or 35 mg/kg/day (69%) than those given 5 mg/kg/day (14%). The incidence of these tumors in rats given 5 mg/kg/day (29.5 mg/m2) was significantly greater than in controls. In addition, preliminary data from 2 independent reports of 6-month studies in rats reveal liver tumors which in one study are classified as malignant.
Mutagenesis: Although no genotoxic potential was found in a conventional battery of in vivo and in vitro tests with pro- and eukaryotic test systems with drug metabolizing systems present,increased levels of DNA adducts have been found in the liver of rats exposed to tamoxifen. Tamoxifen has also been found to increase levels of micronucleus formation in vitro in human lymphoblastoid cell line (MCL-5). Based on these findings, tamoxifen is genotoxic in rodent and human MCL-5 cells.
Found here:
http://www.druginfonet.com/tamoxfen.htm#WARNINGS