Black seed is a plant. People have used the seed to make medicine for over 2000 years. It was even discovered in the tomb of King Tut.
Historically, black seed has been used for headache, toothache, nasal congestion, asthma, arthritis, and intestinal worms. It has also been used for "pink eye" (conjunctivitis), pockets of infection (abscesses), and parasites.
Today, black seed is most commonly used for asthma, diabetes, hypertension, and many other conditions.