SO YOU’VE GONE on a couple dates with her. Maybe you’ve done the whole romantic-evening-under-the-stars thing, brought it back to your place for a night of Barry White tunes. Next thing you know, your heart is pounding with the intense feelings of infatuation, and you can’t seem to think of anyone but her.

Can you call it love yet? Or is there a shallower emotion at work here—like, say, lust?

“Lust is a neurotransmitter love cocktail, [almost like] a drug,” says Megan Fleming, a certified sex and relationship therapist. “It’s a common cognitive distortion. If we feel it, we think it’s true [that we’re in love].”

Broadly speaking, both men and women often confuse emotions surrounding love and lust in the early stages of a relationship. Both sets of emotions, fueled by neurotransmitters like dopamine, are largely driven by physical attraction—especially when that physical attraction results in steamy sex.

The key difference, Fleming says, is that lust is primarily derived from those physical (and, yes, carnal) impulses. In the initial phase of romantic love, people gauge their new partners and develop feelings for them based on relatively surface-level characteristics.