You seem like you're losing some hair?
Have you noticed shedding?
Usually shows up on your pillow in the morning or in the shower drain.
Check you hairbrush too.
If you're in your 50's with a full head of hair then you're probably not experiencing MPB. Usually MPB will show itself at least with a receding hairline by mid 30's.
When you come off cycle and your DHT levels drop you'll probably see the hair start to fill in again pretty quickly.
As far as impurities in the gear I don't know what could be in it that would cause hair loss.
True most of the raws used to produce UGL gear are from China.
The truth is most of the "Pharm grade" gear being sold isn't truly "Pharm grade" but is also produced with the same powders from China.
I know a lot of guys will ague that point because they want to believe that their gear that they're paying top dollar for is produced with Pharm grade components.
Anyone can add a picture of a guy in a lab coat to their website along with pictures of "laboratory settings" and claim it is "FDA approved"or some such.
I don't know of any country giving it's FDA or similar agency approval to any "lab" selling AAS online. That would lead to US DEA investigations and a lot more seizures and arrests.
Most gear online is UGL regardless of claims to the contrary IMHO.
I know a lot of people choose not to believe that.
The only way to prove it one way or the other is to go to the country where the "lab" is at and pay it a visit, snap your own photos and post them here on IMF...
The above is just my opinion, not meant to sway anyone else's opinion or belief.