Marriage counsellors may soon be taking a more Shakespearean approach to solving troubles of the heart, by administering love potions to boost couples' feelings for one another, according to a leading scientist.

Greater understanding of the brain chemistry of love has revealed hormones that could be given to couples to rekindle faded passions or diminish problematic feelings, says Larry Young, an expert in the neuroscience of social bonding at Emory University in Atlanta.

Writing in the journal Nature, Young says scientists are close to reducing the mental state of love to a biochemical chain of events, paving the way for powerful new treatments for the lovelorn. Trials are already under way to see if offering hormones to warring couples improves on conventional marital therapy, he writes.

Advances in genetics are also on course to transform relationships by making available tests to reveal how committed a prospective partner may be, he adds.

Scientists have identified two hormones, oxytocin and vasopressin, which appear crucial in forming a close bond with another person. Tests in sheep found that an injection of oxytocin was enough to make a ewe form an immediate bond with lambs that were not her own.

Men with a gene that makes them less responsive to vasopressin are less likely to marry their partners and more likely to have a marital crisis if they do, Young explains. The hormones are released in the brain during childbirth or sexual stimulation.

"The view of love as an emergent property of a cocktail of ancient [brain chemicals] raises important issues for society. For one thing, drugs that manipulate brain systems at whim to enhance or diminish our love for another may not be far away." Young writes.

Young's research suggests the biochemical basis of love taps into the same brain circuitry as addiction, explaining the strong urges the emotion evokes. While little is known about the genetics at play in personal relationships, further studies may identify new genes that companies could exploit to develop partner "compatibility tests".

"Perhaps genetic tests for the suitability of potential partners will one day become available, the results of which could accompany, and even override, our gut instincts in selecting the perfect partner. Either way, recent advances … mean it won't be long before an unscrupulous suitor could slip a pharmaceutical love potion in our drink."