“It’s still a very alert lobster, but there’s no sign of agitation, no flailing of legs, no trying to pinch you,” she said. “So calm, in fact, that you’re able to freely touch the lobster all over without them trying to strike at you or to be aggressive in any way.”

This method is preferable, she said, to dropping a live crustacean into boiling water without the marijuana.

Ms. Gill, 47, grows the marijuana at her home, and she said she had a license to do so. Voters in Maine narrowly approved a measure in 2017 to legalize recreational marijuana for adults over 21.

But on Thursday evening, Ms. Gill said, she received notice from Maine’s health department that she was using the marijuana in a prohibited way because “it is supposed to be used only for myself and not a lobster.”

Ms. Gill, a self-professed animal lover, has faced a quandary since starting to serve lobsters about six years ago. She began investigating the marijuana idea this year with the staff at her restaurant, which is about 50 miles southeast of Bangor. As the experiment got publicity, some wondered if it was a marketing gimmick, but Ms. Gill maintained it was not.

Staff members have tested their urine after eating the marijuana-treated lobsters, she said, and no trace of the drug has been found. In the latest experiment, Ms. Gill’s 82-year-old father has been eating copious amounts of marijuana-sedated lobster every day; he will soon take a blood test.

She said she hoped her tests could prove to the state that the lobsters were not absorbing the marijuana. But as of Thursday evening, it appeared that plans toward making the lobsters available to the public had stalled. State regulators are still examining the issue, Ms. Spencer said.