Bit of a PL here but when they manufacture inject-able medications, or a pharmacy/hospital compounds them (Sterile Compounding), the facilities are required to have separate rooms in which to do it. These rooms are required to have either an entirely separate air and ac system or be separately filtered from the rest of the building. They are required to be sealable to the outside world, up to and including being airtight. When you go in there to do work, you have to wear full equipment, a mask, hairnet, beard net, goggles, little booties over your shoes, nitrile gloves, and a disposable shawl. This is to protect you to an extent, but its mostly to keep all of the nasty shit that humans perspire, get covered in, or shed from getting into the medications because that shit can be disastrous. Pets can give you toxoplasmosis, human skin cells can give you all fucking sorts of diseases, and hair or hair particles can give all sorts of nasty shit because we don't generally clean hair to a sterile standard. You cannot just go "oh well whatever, it's just one bottle" because when you have diseases like that and you are INJECTING THEM DIRECTLY INTO YOUR BLOODSTREAM, you have bypassed literally all but the very last line of your body's lines of defense against disease, and more than likely your white blood cells are not going to be prepared for whatever the fuck comes in with the troonshine, and it will manifest 10 times worse than it would otherwise. You can't just do this shit in your kitchen, those regulations aren't just knee jerk reactions put in place by terrified lawmakers, they are necessary safety measures to keep you from giving yourself an embolism or sepsis or a parasite.
That looks to me like a cat hair in the bottle, and assuming they follow their own guide and just do the mixing and "sterilizing" in an open beaker than of fucking course there's going to be cat hair in it. Manufacture of inject-able medications shouldn't be fucking done in the same BUILDING as a cat, let alone in a room where their hair is. This shit is especially spooky because Estrogen is, surprise surprise, a Hazardous medication. Not just because of its severe adverse hormonal effects on men, but because too much of it in your system can cause all sorts of nasty effects in both Sexes. This fucker is mixing super hazardous substances in what might as well be his bathtub, in a place where not just human hair but pet hair and lord knows what else can get into the mix, and judging by the way the people in the screenies were talking about it, this happens fairly regularly, and he just doesn't care.
Do not fucking use black market IV drugs, if there's one thing you learn from using this site, Do not fucking use black market IV drugs, you have much more to lose than with pills or powder, sepsis is a fucking horrible way to go.