My son is 25 years old and I was concerned about having him vaccinated when he was a baby. This was before people really began questioning vaccine safety and there wasn’t much research available. The Internet was still in it’s infancy, as well. I hadn’t read much about it, but it was just a “feeling” I had. I voiced my concern with his pediatrician at the time and he laughed at me. I was basically peer-pressured and guilted into having my son vaccinated. I wish I would have been a stronger person back then. I was quite young. I regret going along with it at the time, and it’s still one of my biggest regrets to this day. I should have listed to my intuition. He is healthy, thank goodness, but is it really worth the risk?
Products may contain impurities developed in the production stage due to probably lack of hygiene in illegal drug factories. In addition, the active ingredients and their amounts are most likely to differ from the package label promises.
Furthermore, these products have also revealed traces of medicinal substances and other harmful ingredients previously removed from the market for safety purposes. In the manufacturing may have been used construction industry substances as a substitute for the correct medicinal substances, for example. Illegal substances may cause symptoms such as allergic reactions. 
Estradiol's efficacy seems to vary widely with the person and the particular vehicle: I was on transdermal patches for two years ( , 2 patches changed twice weekly – considered a "high" dose of 17-beta estradiol), and my levels mostly stayed around 100 pg/mL, and I needed 100mg spironolactone daily to keep my testosterone down. When I switched to injections of Estradiol Valerate, as I was "titrating up" my testosterone was unmeasurably low at the same E2 level my patches were delivering. (I had decided to drop spiro at the same time due to it's side effects: for me it seemed to be fogging my brain and inducing suicidal ideation.) Increasing the dosage had the effect of adding a cup-size to my breasts after about two months of injections, after two years of HRT, at age 53 and with b-cup breasts already. This story is not unusual in the community, and it led me to try this form of HRT.