ST. LOUIS (KTVI) — Many people who have COVID-19 experience a loss of taste and smell. For most people, it lasts about two to three weeks. But between 5% and 7% of the millions of people in the U.S. who have had the virus still have problems with those senses two to three months after they’ve recovered.

Doctors at Washington University School of Medicine are now studying whether you can retrain the brain to recognize smells, and they are enlisting patients for a three-month study.

The study involves giving the participant four essential oils of their choice to smell twice a day for an extended period. Half of the group will get standard olfactory training and another half will get visual training.

The study is also trying to determine if an object can make a brain recognize a smell.

Doctors say most patients are concerned about not being able to smell smoke or natural gas. Others are no longer able to appreciate food and other common pleasures we all take for granted. Still others report a distorted sense of smell that is constant.

Doctors say loss of taste and smell can be permanent, and they hope to have the results of their study by May.

To be part of the Washington University study, email otooutcomes@wustl.edu.