tbh I'm at a loss for words. I don't really know what to say. Its clear that Mathew is only doing this for his safety and he would never do something to hurt Jin (as seen in the chapters where he himself got drugged) so I'm having a hard time believing that the syringe is actually a drug. Where would he even get a syringe full of drugs? I think that's just the antidote prescribed by the doctor. If I'm not mistaken i think she mentioned that fatigue might be a symptom to it. Mathew maybe gave Jin a larger dosage to keep him out for longer. Tbh it would be so out of character for him to suddenly change his morals especially since his relationship with Jin seems to be blooming. I hope the author wont dissapoint