i think that since ritalin has talc, it can harm ur lungs when sniffed. look it up. i wonder if it was anyworse than shooting..which is how i rationalized my iv ritalin days bc i was like fuck it, everyone sniffs it and has no problems, but i guess i got lucky just like many sniffers.
anyway 3 months aint much of a time for that normal daily adult and teen dose of 20mg methylphenidate tablets 2x a day.
maybe do an extraction and make a nasal spray if u are concerned or wanna play it safe.