contains no actual liquid eyeliner a glorified dried up marker [SEP] yes this product causes irritation it made me quite irritable the first time i used itfirst off this is not a liquid eyeliner pen there is no liquid eyeliner in it whatsoeverit is in essence a glorified dried up marker not even a sharpie more like the cheap markers that come with the coloring pages at walgreens or the dollar stores i am not knocking elf but this is quite sub par i would be miffed if i had not gotten it on sale for like the marker tip actually retreats into the pen itself when you press with any pressure whatsoever which is awkward and you have to then pull it back out and just hope it doesnt keep happeningnot easy to apply mostly because it is not easy to apply dried up ink from a cheap marker tip to your slightly moist eye lid areai was not able to achieve any type of dramatic dark eye liner with this pen it looked like i had tried to put it on with a you guessed it dried up marker you shake the pen and hear nothing because there is nothing in there to be mixed by the shaking it is literally just a dried up markerit is however just as waterproof as a dying sharpie