No word on where this happened or when, but it seems somewhat recent. Check out the video -- you see the patient trying to pick up his prescription of ivermectin, which the pharmacist flat out refuses to fill ... noting it's not FDA approved for the virus.

The customer is adamant that it was prescribed to him by a licensed physician, and that the pharmacist is breaking the law by overriding his doctor's orders -- but the pharmacist tells him to kick rocks, and to complain to whoever he feels he needs to complain to.

While the pharmacist does recognize it is a legit drug approved for certain things -- like parasitic illnesses -- it has NOT yet gotten the official green light by the feds ... something the man tries to push back on by saying it's an "off-label" treatment.

The pharmacist won't budge, though ... and the video cuts out before we can see how this headbutt ended. Presumably, the man left that location empty-handed ... but it brings up an interesting dilemma.

For starters, it's unclear how the pharmacist even knew what the guy needed ivermectin for -- there's no indication if the Rx noted it was for COVID, or if the pharmacist simply assumed/deduced it. The man sorta gives it away by not pushing back on his premise.

There's also the issue of whether a pharmacist can legally do this -- refusing to fill a prescription -- and the answer is yes ... in some states, that is. California is one example.