As you're settling in your summer flings you may be wondering if that special someone loves you back. Fortunately, science can provide a more determinable answer than gazing into your lover's eyes ever will. Simply ask yourself the following questions: "How have his/her kidneys been functioning lately?", "What's his /her current Nerve Growth Factor (NGF) level?", and "Has the oxytocin been elevating?" Love is not as abstract as romantics like to imagine. Most of the process can be answered through science.Even before that first encounter, your body produces the hormone testosterone (in both males and females) which causes one to lust and keep an eye out for a potential mate. Who you find compatible depends on how people's sweat glands smells or what they look like. One study, in the University of New Mexico, found people look for symmetry. If a person produces the right amount of estrogen then their waist-to-hip ratio presents a more attractive figure for the opposite sex. From the moment you set eyes on someone your body is responding to hormones. That feeling that your heart's racing and all that nervous sweating that occurs is all a result of the norepinephrine that your body is releasing. The amount of love you hold can be measured by the concentration of NGF neurotrophins in your blood. NGF is thought to be associated with how infatuated someone is. The study, published in the journal of Psychoneuroendocrinology, found that when people claimed to have "passionate love" the NGF had a higher than normal concentration. The hours spent day dreaming of your lover and that overall great feeling is inspired by the release of neurotransmitters such as dopamine which is the same chemical released when someone's smoking or snorting a line of cocaine.If that's not enough to convince the person they're madly in love, the body will start releasing serotonin which uses the same chemical receptor when one takes the drug ectasy, MDMA, or psychedelic mushrooms. This is also the state where people start acting insane and making irrational decisions for the sake of love. Interestingly, the serotonin doesn't always rise in people and sometimes even lowers which will cause certain people to be depressed or anxious while feeling in love at the same time.All these chemicals in the body don't stick around for long though. At a certain point these chemicals need to stop being released if for nothing else but the healthy state of our mind. The usual drop occurs in about a year. The NGF levels, which were previously mentioned as the chemical associated with love, was found to drop in only 8 months. At this point, people will report feeling like they've lost that initial attraction or state of love and may separate from their partners. This is also the time when love actually depends heavily on the social aspects of the bond for it to last.However, even then there are a few hormones which can be detected to help determine how long or strong the bond between two people will last. Oxytocin is one of the main chemicals that's released to strengthen this bond. Without getting too Freudian about it, it's the same chemical that's released to create a bond between a mother and child as the child suckles her breasts. It's no coincidence that it's also released by both sexes during an orgasm. Theoretically, the more sex you have, the more oxytocin is released and the stronger the bond becomes. There's also vasopressin which is structurally similar to oxytocin, both came from the same genes 400 million years ago. Vasopressin is provided to patients during heart attacks. It's used during septic shock when the chemicals such as dopamine are not working. Coincidentally, our body uses vasopressin to strengthen the bond between two people when dopamine levels drop. The French nobleman, La Rochefoucauld, once wrote "True love is like ghosts, which everybody talks about and few have seen." This is only true if scientists are among the few who've seen it.