"i&#039;m an eighteen year old female and i started taking these 100mg doxycycline monohydrate pills only four days ago because they worked great for my brothers. i&#039;ve been taking them with tons of water and food. they seem to work so far but i&#039;ve been waking up with terrible migraine-like headaches and confusion. i&#039;m usually an early riser and a morning person but these make me feel really nauseated. i don&#039;t recommend them for anyone who gets migraines like i do."