Saffron is a plant. The dried stigmas (thread-like parts of the flower) are used to make saffron spice. It can take 75,000 saffron blossoms to produce a single pound of saffron spice. Saffron is largely cultivated and harvested by hand. Due to the amount of labor involved in harvesting, saffron is considered one of the world's most expensive spices. The stigmas, and sometimes the petals, are also used to make medicine. People use saffron most commonly for depression, anxiety, Alzheimer's disease, menstrual cramps (dysmenorrhea), and premenstrual syndrome (PMS). Saffron is also used for many other conditions, but there is no good scientific evidence to support many of these uses. In foods, saffron is used as a spice, yellow food coloring, and as flavoring agent. In manufacturing, saffron extracts are used as fragrance in perfumes and as a dye for cloth. How does it work? Saffron contains chemicals that alter mood, kill cancer cells, decrease swelling, and act as antioxidants.