Science explains love in 3 steps. Lust, Attraction and Attachment.
1)Lust: It is driven by the sex hormones, testosterone and oestrogen, biologically simple, men are attracted to women with symmetrical face, full lips, breasts and wide waists. This stage is biologically simple.
2)Attraction: This is the stage where you are deeply in love and you can’t think of anything other than your new partner, scientists think there are 3 main neurotransmitters involved here, adrenaline, dopamine and seratonin. Firstly adrenaline along with the stress hormone cortisol are released during the first few weeks of your new relationship.
Increased dopamine decreases your need for sleep and food by increasing your energy levels. Similar affect as drugs.
3)Attachment: This is the most important stage, the hormones responsible are oxytocin and vasopressin, both the hormones are released by both men and women when they kiss, cuddle and have sex.
Oxytocin is also responsible why you love your family, whenever you touch your parents and siblings, the hormone is released.
I do apologise, for ruining the magic, true love is magical, it just cannot be explained by science.