That’s why I home brew, you have control over the solvents, and oils, and sterility comes from filtering the ingrediants into the vial. I don’t think sterility of UGL products is the problem, more likely the solvents, many people don’t like BA content of more than 2%, or don’t react well to Ethyl Oleate. Neither of these substances are necessary to put steroid powder into solution, unless you are using high mg/ml test, eg 400mg/ml or higher.
Stick with products that don’t use EO. Some UGL don’t give you a breakdown of ingrediants and proportions, so avoid testosterone over 250mg/ml.