I never use SERM but I'd sure love to see the studies that show that they are very toxic.
Even the uterine cancer one shows an very tiny percentage of woman getting the cancer over many years - (The authors conducted a retrospective cohort study of 8,431 US women (145,876 woman-years) evaluated for infertility during 1965–1988. Through 1999, 39 uterine cancers were ascertained by questionnaire or cancer and death registries.) and at high doses - (Uterine cancer risk increased with clomiphene dose (RR = 1.93, 95% CI: 0.9, 4.0 for >900 mg), and where at increased risk due to obesity - (was more strongly associated with clomiphene among nulligravid (RR = 3.49, 95% CI: 1.3, 9.3) and obese (RR = 6.02, 95% CI: 1.2, 30.0) women, with risk substantially elevated among women who were both obese and nulligravid (RR = 12.52, 95% CI: 1.5, 108.0).)
I believe that rate of uterine cancer in infertile obese woman over that many woman over than many years is probably still substantial in and of itself and the clomid correlation may just be casual.
Again, not disagreeing with its potential to be toxic but I believe even the glycerine and glycol solution that most RC suppliers use is more toxic and that is minuscule to say the most. I'm debating the actual data being conclusive.