It is impossible to believe that all this was done hormones that cause biochemical reactions in the human body. In love depends on a "cocktail" of substances that are released by the body. The first stage of love - adrenaline and dopamine. They are responsible for your "madness." Heart skips a beat at the sight of a loved one - it's adrenaline. Dopamine does not allow you to step back and make persevere passion. The action of this hormone is similar to that of cocaine, you feel an unprecedented surge of strength and desire to constantly be with loved ones.
Euphoria is phenylethylamine. It is also in products, for example, black bitter chocolate, but from the gastro-intestinal tract substantially reaches the brain. Acute stage of love is held under the influence of phenylethylamine. So you constantly think about the subject of love, deprived of sleep and appetite.
Then to the existing "cocktail" of substances joins endorphin. This is called "the hormone of happiness," he relieves pain and helps to cope better with stress. A man in love becomes completely controlled his own body, to produce hormones, drugs.
Romantic time of love lasts about three years. The most common period - 1, 5-2 years. Happy couple moving to the next stage of love - "endorphins" attachment. Then the female hormone oxytocin positions itself requirement to continue the race. Progesterone causes loving people desire to care for each other.
Rose-colored glasses are absolutely transparent relations in three years. This is a very difficult time for love. The couple must learn to live in perfect harmony without chemical "fuel" hormones. If they do not, they are likely to part.