If thousands of practitioners and millions of people around the world are using it, are they all wrong?

That’s one of the questions posed in Just One Drop, a new documentary that explores “the history, the mystery [and] the promise” of homeopathy.

Filmmaker Laurel Chiten traveled the world to learn about the alternative medical system developed more than 200 years ago. It’s based on the idea that “like cures like”—that a disease can be cured by a small dose of a substance that causes similar symptoms. It employs remedies made from highly diluted substances from plants, minerals and animals, to stimulate the body to heal itself.

While it’s been written off by much of the medical community as bogus and unproven, it has a rich history and advocates across the world. Just One Drop “explores the controversy, reveals the rich history, dispels myths and misconceptions, and asks whether or not homeopathy been given a fair shake,” according to the film’s website.

Natural Products Expo East attendees can catch a screening of the documentary Wednesday, Sept. 13 in Baltimore, and participate in a discussion with Chiten led by Natural Grocers by Vitamin Cottage’s Alan Lewis.