PORTLAND — Maine’s naturopathic doctors must be licensed by March 1 under terms of a state law enacted more than two years ago that sets professional standards and seeks to protect patients who choose alternative therapies.

Maine, along with New Hampshire and Vermont, is among 11 states that require licensure, according to the American Association of Naturopathic Physicians. The others are Hawaii, Alaska, Washington, Oregon, Utah, Montana, Arizona and Connecticut.

The licensing requirement sets educational and ethical standards for the profession. It also allows naturopaths to expand the scope of their practices by giving them the authority to order more diagnostic tests and prescribe certain medications.

For consumers, the law provides a way to check on a naturopath’s credentials and report complaints about treatment to the state Board of Complementary Healthcare Providers.

“It is possible to get a naturopathic doctor degree through the mail with no formal training whatsoever, through a correspondence course,” said Devra Krassner, a naturopathic doctor who practices in Portland. “If you’re practicing in a nonlicensed state, virtually anybody that wants to can call themselves a naturopathic doctor and begin practicing, because it’s not regulated in any way.”