Asafetida, also called hing, is a resin from the Ferula plant. Raw, it smells strongly of sulfur. Cooked, it takes on a garlic-like flavor. Traditional medicine relies on it mainly as a digestive aid.
People take asafetida in tiny amounts while cooking or in capsule form. The sharp flavor usually goes into hot oil or ghee right at the start of a dish. Some supplements offer concentrated extracts.
Watch out if you have allergies to plants in the carrot family (Apiaceae), such as celery or carrots. Large doses can upset your stomach. Solid scientific backing is thin for most uses, so this is not a stand-in for medical treatment.