In a desperate bid to find treatments for people sickened by coronavirus, doctors and drug companies have launched more than 100 human experiments in the United States, investigating experimental drugs, a decades-old malaria medicine and cutting-edge therapies that have worked for other conditions such as HIV and rheumatoid arthritis.

Development of effective treatments for covid-19 would be one of the most significant milestones in returning the United States to normalcy. But the massive effort is disorganized and scattershot, harming its prospects for success, according to multiple researchers and health experts. Researchers working around-the-clock describe a lack of a centralized national strategy, overlapping efforts, an array of small-scale trials that will not lead to definitive answers and no standards for how to prioritize efforts, what data to collect or how to share it to get to answers faster.

“It’s a cacophony; it’s not an orchestra. There’s no conductor,” said Derek Angus, chair of the department of critical care medicine at University of Pittsburgh School of Medicine, who is leading a covid-19 trial that will test multiple therapies. “My heart aches over the complete chaos in the response.”