The onion seeds are used as a spice and are a major part of the Indian Spice palette. The oil is also used in cooking flavoring in various parts of the world. While the seeds are used commonly as a spice, the onion seed oil offers several health benefits, The oil is good for the skin. It can cure acne if applied externally on the skin. It can also remove skin fungus and in general provide healthier complexion. It is also good for preventing hair loss.