2. Your thoughts about them border on obsessive.
When you fall in love, levels of the hormone serotonin (which has a calming affect) appear to drop. Serotonin levels also drop in people with Obsessive Compulsive Disorder, which might explain just why you can’t stop thinking about your crush.
5. In women, testosterone goes up, but in men it goes down.
This kind of evens things out. “It’s as if nature wants to eliminate what can be different in men and women, because it’s more important to survive [and mate] at this stage,” researcher Donatella Marazziti told New Scientist.
6. If you’re lucky, they like you too.
That’s most likely if they have genes that are different to yours, according to one experiment in which women smelled men’s tshirts. They overwhelmingly prefered those tshirts belonging to men with different immune system genes from their own.
7. You can also expect euphoria, sleeplessness, loss of appetite, and a rush of motivation.
You can say thanks to neurotransmitter dopamine for that. Dopamine is also what is responsible for making love feel addictive (among the many, many other things it does).
11. The hormone oxytocin can also be triggered by kissing.
Often erroneously called the “love hormone” or “moral molecule”, oxytocin can do a lot of things depending on the context. But it is thought to be what helps keep the love in a relationship alive long after the initial honeymoon period is over.