I would be at least a bit worried too, but unfortunately the only reason this exists is because corporations decided to wall off access to producing their drugs legally so they could continue to exploit vulnerable people for profit.

For a lot of the people using this tech, it's the only way they'll get life saving medication, and without it, they'll die. If that's the kind of gamble they have to make, a possible risk of impurities or negative reactions is better than the considerably less desirable option of death.