The invention of the printing press in the 15th century led to an explosion in herbal medicine, as recipes for treatments could be copied and used by anyone who could read. By the 17th century, Nicholas Culpeper had put together a book of herbal remedies, which became very popular. In his book, Culpeper built on the idea of the 'doctrine of signatures', which the early chemist Paracelsus had first though of. He believed that how a plant looked provided clues as to what ailment it would cure. By 1985, the World Health Organisation agreed that herbal remedies are an important part of healthcare.
Herbalists try to find the underlying cause of an illness rather than treat the individual symptoms.
They believe that the use of tinctures and herbal tonics can help the body to heal itself by restoring harmony and balance and activating the body's 'life force'. Herbal 'synergy' is, herbalists believe, the key principle of herbal medicine. Their remedies are extracted from leaves, petals and roots of plants and are a complex mixture of lots of different compounds. While a conventional pharmaceutical will usually be a single active ingredient, the idea of herbal 'synergy' explains that the hundreds if not thousands of constituents of a plant extract all work together to treat an illness. For example, ephedrine, an early anti-asthma drug, was first isolated from the herb Ephedra, traditionally used to treat chest complaints.