A jelly-like substance derived from algae. For hundreds of years, agar has been a popular food product in Japan. It is often used as a gelatin substitute, and it may also have medicinal properties; agar is a popular folk remedy for a variety of conditions including constipation and diabetes.

Agar is safe for diabetics, and it is an excellent source of iron, fiber, and calcium. The substance is used in some cosmetics and personal lubricants as a thickening agent.