HELLO, NEW TO THIS POST,OLD TO DIABETES, I AM NOT ASSOCIATED WITHANY MEDICAL FIELD WHAT SO EVER. I HAVE NEVER KNOWN INJECTION TO CAUSE HEAD PAIN,SINCE YOU ARE FAIRLY NEW TO ANOTHER MED, MIGHT BE TENSION OR ANAXITY.TOOK ME 16MOS BEFOR I WOULD TAKE LANTUS AT NIGHT. I CALLED THE MANUFACTURE AND ASKED THEIR RECOMMENDED HIGHEST DOSE.I THOUGH I WOULD BOTTOM IF I TOOK IT AT BEDTIME.I WAS TOLD I COULD TAKE 100MG AND WOULDNT BOTTOM OUT.BUT EVERTIME I INJECTED MYSELF.I WENT INTO A FULL BLOWN PANIC ATTACK, ITS OK NOW. I TAKE 80MG AT NIGHT,DR.ORDERS BUT IT HAD ME THERE FOR A WILD.TALK TO YOUR DR.AND YOUR METER IS YOUR BEST "FRIEND" . WHATEVER IS GOING ON I RULE OUT GLUCOSE LEVELS FIRST.TEST