contraceptive

Plant chemicals hope for 'alternative contraceptives'

Chemicals from dandelion root and the "thunder god vine" plant have long been used in traditional medicines.

Now, Californian researchers have found they can also block fertilisation.

A UK sperm expert said the discovery could lead to a new and novel approach to male contraception.

But the compounds existed at such low levels in plants that the cost of extraction was very high, the US team said.