Ive only Had Minor headaches, i find that when i takle tylonal before i smoke it eliminates the headache before it starts. I also catch some short memory loss but its not perminant. I have Blacked out a couple times but i dont know if its the weed or not, doc said its very possible because it slows your brainwaves down, and if your already tired it can cause a small siezure or passing out, is this true anyone? Ive smoked for about 5 years and this only happened twice recently, i dont blame Mary Jane.