It may not be the most romantic gesture but scientists are developing drugs that can boost that most human of emotions.

They are studying the brain chemistry responsible for the complex feelings that draw us to a particular member of the opposite sex and help keep us monogamous.

Animal testing is beginning to shed light on the complex neural and genetic components of love in the same way they have led to pharmaceutical therapies for anxiety, phobias and post-traumatic stress disorders.

The behavioural scientist Professor Larry Young, of Emory University, Georgia, writing in the journal Nature, said: "For one thing, drugs that manipulate brain systems at whim to enhance or diminish our love for another may not be far away."

Experiments have already shown a nasal squirt of the hormone oxytocin enhances trust and tunes people into others' emotions.

Websites are marketing products such as Enhanced Liquid Trust, a cologne-like mixture of oxytocin and chemical scents called pheromones "designed to boost the dating and relationship area of your life".

Prof Young said: "Although such products are unlikely to do anything other than boost users' confidence, studies are under way in Australia to determine whether an oxytocin spray might aid traditional marital therapy."

Prof Young said: "The hormone interacts with the reward and reinforcement system driven by the neuro-transmitter dopamine – the same circuitry that drugs such as nicotine, cocaine and heroine act on in humans to produce euphoria and addiction.

"Dopamine-related reward regions of the human brain are active in mothers viewing images of their child. Similar activation patterns are seen in people looking at photographs of their lovers."