Opium consists of the dried milky sap obtained from the pod of the opium poppy, apaver somniferium. It is a sticky, dark substance, hence the street names "op," "hop," "tar," and "black stuff." Opium, in its raw form is likely to be contaminated with bacteria and fungi. This substance contains many alkaloids, including morphine and codeine (central nervous system depressants), and papaverine (a smooth muscle relaxant).

Opium is the crudest form and also the least potent of the Opiates. Opium is the milky latex fluid contained in the un-ripened seed pod of the opium poppy. As the fluid is exposed to air, it hardens and turns black in color. This dried form is typically smoked, but can also be eaten. Opium is grown mainly in Myanmar (formerly Burma) and Afghanistan. Opium is highly addictive. Tolerance (the need for higher and higher doses to maintain the same effect) and physical and psychological dependence develop quickly.

Opium is the air-dried milky exudation obtained from excised unripe fruits. It is extensively smoked as an intoxicant. Commercial products are called Turkey Opium, Indian Opium, Persian Opium, Chinese Opium, and Egyptian Opium, and they differ in appearance and quality. Opium is largely used for manufacture of morphine, codeine, narcotine, laudenine, papaverine, and many other alkaloids. It is also the source of the toxic and extremely habitforming narcotic heroin or dimorphine, prohibited in some countries. Seeds contain no opium and are used extensively in baking and sprinkling on rolls and bread.

Opium poppy seeds are the source of a drying-oil, used for manufacture of paints, varnishes, and soaps, and in foods and salad dressing. Oil cake is a good fodder for cattle. Seeds used for preparation of emulsions (white-seeded varieties preferred); the bluish-black varieties are generally used for baking. Stems used for straw. Lecithin has been extracted from poppy seed meal. Seedlings are eaten as a potherb in Iran. As the peony flowered poppy, the opium poppy is widely grown as an ornamental, even here in the US, where it is illegal to grow.