Safi is for blood purification, it’s not exactly a cure for pimples. There are plenty of other reasons for acne, for instance, age, hormones, oily skin, bacteria, diet, air pollution, etc.
Most claims about ayurvedic/unani medicines being dangerous and containing arsenic and lead are bogus. Hamdard is a very authentic and age-old corporation of sub-continenet. All of their herbal products and medicines are safe and genuine (including safi).
If blood purification is your goal, and u don’t wanna resort to any medicine, then try Chuqandar (beet root). It’s an excellent blood purifier. It also has a lot of iron and folate, so its a wonderful vegetable for women of child bearing age in general.