Using plants for medicinal purposes has a long tradition dating back thousands of years in countries such as China and India. According to the World Health Organization (WHO) they still form the basis of traditional or indigenous health systems for majority of populations in most developing countries. Today in several parts of the world, there is growing credibility for traditional Chinese medicine (TCM), Ayurveda, Unani and also for complementary or alternative medicine utilized in industrialized countries. On account of several significant contributing factors herbal medicine, once discounted as superstitious/irrational medicine of native and ancient cultures, is emerging as a popular alternative and even supplement to modern medicine. In acknowledgement of the worldwide demand for holistic treatment practices, the WHO is encouraging, promoting and recommending its member countries to reintroduce time-tested medicinal plants and derivatives into primary health care, where modern medicine is unavailable as low-cost alternatives.

According to Food and Agriculture Organization of United Nations (FAO, UN), the last three decades have seen substantial growth in herb and herbal product markets across the world. There is a huge global market for plants used in the preparation of phytomedicines as used by traditional systems, homeopaths and herbalists. Such medicines are today available in pharmacies, supermarkets and health food outlets. To enable easier access, traders and crude drug suppliers have extended their market base by supplying medicinal plants, spices and plant extracts to food, flavour, fragrance and cosmetic industries. Today the herbal drug industry is thus a very fast growing sector in the international market. The fact that the global market for herbal products is affected by regional changes in regulatory or marketing strategies is illustrated by its impressive growth in the United States fuelled by passage of the Dietary Supplement Health and Education Act of 1994. Also the United States Food and Drug Administration (USFDA) has published draft guidelines for development of botanical medicines as drugs, reflecting a growing interest in the drug model for these products.

Rapidly rising exports of medicinal plants during the past decade attests to worldwide interest in these products as well as in traditional health systems; 30% of the drugs sold worldwide contain compounds derived from plant material and a far higher figure is associated to a great variety of medicines bought over the counter.

Higher plant products either unmodified or altered, account for 25% of all prescriptions in OECD countries and upto 60% of those in Eastern Europe. These include important therapeutic categories such as contraceptives, steroid and muscle relaxants, antimalarials (quinine and artemisinin), cardiotonics (digoxin) and anti-cancer drugs (Taxol, etoposide, vincristine/vinblastine). These drugs are not amenable to cost-effective total synthesis and require for their production reliable supplies of plant material. About 95 plant species are listed as sources of 121 clinically useful prescription drugs and many more are associated with a large number of OTC drugs. As per a WHO estimate, 80% of the population in developing countries depend on plant-based drugs for their health care needs and it predicts that in the coming decades, a similar percentage of the world population will rely on plant drugs.