Black seeds are also known as black caraway, black cumin, kalonji, and black onion seeds. They come from Nigella sativa, a small plant with pale purple, blue, or white flowers that grows in Eastern Europe, Western Asia, and the Middle East. People have used the tiny black seeds of the fruits of N. sativa as a natural remedy for thousands of years. The seeds can also flavor curries, pickles, and bread in a similar way to cumin or oregano. Black seed oil contains thymoquinone, which is an antioxidant and anti-inflammatory compound that may also have tumor-reducing properties according to what some studies on rats have found. People can ingest black seed oil in the form of capsules or apply it topically to benefit the skin. It is also possible to add the oil to massage oils, shampoos, homemade skin-care products, and fragrances.