Love is driven by three distinct neurochemical stages: lust, attraction, and attachment.

Dr. Helen Fisher's pioneering research using functional Magnetic Resonance Imaging (fMRI) demonstrated that romantic love is not a single emotion, but rather a set of three distinct, yet overlapping, brain systems. Lust is driven primarily by the sex hormones testosterone and estrogen, fueling the basic biological drive to reproduce. Attraction—the obsessive, early stage of romantic love—is fueled by a rush of dopamine, norepinephrine, and a drop in serotonin, mimicking the brain patterns of obsessive-compulsive disorder. Finally, the long-term attachment stage is mediated by the neuropeptides oxytocin and vasopressin. These chemicals foster trust, security, and deep bonding, transitioning the frantic energy of early romance into a stable alliance. This distinct tripartite division explains why we can feel deep attachment to a long-term partner while simultaneously experiencing attraction or lust toward someone else.