A lot of people can't differentiate between love and lust, and a lot of the time the two can get roped up in each other. Any fulfillment of need gets confused with "love" and becomes overused with feelings of desire. Personally I know I have felt mixed in between the two, and have only felt lust for a person when I thought it was love or wanted it to be. It can be scary to look at the person you have your eyes on and question what you feel for them, especially when you realize it might only be lust when you want it to be more, but its one of those things I think people need to put into perspective and be honest with themselves about.
So what exactly is lust? Lust shows in the brain in the same way as someone who is fixated on drugs. The same area lights up in the brain when an addicts getting their fix and when someone is feeling lust or intense physical attraction. It's a state of consciousness thats altered by urge, and is fueled by how you want someone to be or need them to be. Lust can prevent you from seeing the person as who they really are- flaws and all. Intense sexual attraction for someone can eliminate common sense even for the sensible. Pure lust is really only based on physical attraction and illusions on the persons characteristics and traits, but it usually doesn't stick around when you begin to see the real person underneath it. It's simply seeing someone through rose colored glasses.
Love does not entirely remove lust, and lust can bring love depending on the people and the situation. Real love goes farther than physical attraction and requires getting to know each other. But I've learned that even this sometimes doesn't equate to love, it all just depends. Nonetheless, here's how to tell if the butterflies are real:
Focused only on the persons looks
Interested in sex, but not in conversation
It's more of a fantasy than talking about real feelings
Listening to each others feelings
Wanting to make the other person happy or feel fulfilled
Wanting to know more about the person, meeting their family
It's more than just sex
"With love, you care about what drugs they're on; with lust, you feel like you are on drugs."
I think listening to gut feelings in the early stages of being involved with someone and keeping presence of mind is important. Hormones can be messy and that can make it harder to make healthy decisions concerning the person or staying centered. It's a challenge, but maybe finding love in the end is worth it.