I had severe headaches when I tried lamatical for the second time. I had been off all meds for a year and started with 25mg. I also had bad flu like symptoms and no amount of tylenol took the pain away. I did not take any more and it took 4 days for the side effects to go away. I am not into pain. The first time I took lamatical I didn't have any side effects at first (I was also on 4 other antidepress and anti-anxiety meds) but I ended up so sick that I don't remember anything for 2 weeks and ended up in the hospital with acute liver failure looking at a possible liver transplant. My husband said that I kept complaining of severe headaches that I accidently oded on tylenol. I am now taking lithium, but ended up with bad heartburn and chestpain and lower back ache when they tried to increase it from 300 to 600mg, so I just take 300 at this point.