How did opium first reach China before the British trade expanded?

Opium was first introduced to China by Turkish and Arab traders in the late 6th or early 7th century CE. Initially, the drug was used in limited quantities, primarily taken orally to relieve pain and tension.1

The nature of its use changed significantly in the 17th century when the practice of smoking tobacco spread from North America to China. Following this, the practice of smoking opium became popular throughout the country, leading to a rapid increase in addiction and importation during the early Qing dynasty. By the early 18th century, the Portuguese began importing opium from India to sell in China for profit, establishing a commercial pattern that preceded the British dominance of the trade.1