Half of the US hydroxychloroquine supply - the drug Trump touts as a possible coronavirus treatment - has been abruptly cut off

• The US has abruptly lost 47% of its supply of hydroxychloroquine, the drug touted by the president as a potential treatment and preventive measure for COVID-19.
• Much of the drug has been produced in India, which banned exporting it.
• Despite the president's claims, there is little scientific evidence that the drug is effective for fighting the novel coronavirus. It's normally used to treat lupus, arthritis, and malaria.
• Visit Business Insider's homepage for more stories.

The US has abruptly lost about half its incoming supply of hydroxychloroquine, the drug President Donald Trump touts with little evidence as a drug to fight COVID-19.

Hydroxychloroquine is normally used to treat and ward off the symptoms for malaria, arthritis, and lupus. Much of it is developed in India, which on Saturday banned its export, according to Bloomberg News.

India provided about 47% of the US's supply, according to data from 2019 analyzed by Bloomberg News, and just a "handful" of the US suppliers of the drug are based outside of the country.

At a press conference on Saturday, President Trump said a request to India to release shipments of the drug that had already been ordered was under "serious consideration." The outright ban was announced by India's Directorate General of Foreign Trade on April 4, although the country had already limited exports of the drug prior to the Saturday ban.

The president as recently as a Sunday press conference has said he believes the drug should be used against COVID-19. He's even implied he might take it himself as a preventative measure.

"It's a powerful drug on malaria, and there are scientific works on this. Some strong signs," Trump said Sunday, adding that the US had a stockpile of over 29 million hydroxychloroquine pills that could be used.

"What do you have to lose?" he has said repeatedly, despite the medication's potential side effects and its unproven effects on COVID-19 patients. Clinical trials are currently underway.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases and member of the White House Coronavirus Tasks Force, has multiple times said the evidence on the drug is unproven despite the president's claims. It is still undergoing clinical trials for treating COVID-19.

"In terms of science, I don't think we could definitively say it works," Fauci said during an appearance on CBS's "Face the Nation" on Sunday.

When a reporter at a press briefing on Sunday asked Fauci to answer questions about the drug, the president refused to allow him to answer, moving the press conference toward a different topic.

"He answered that question 15 times," Trump said.

Erin Fox, a drug-shortage expert and the senior pharmacy director for the University of Utah's health system told Business Insider in March that a shortage of the drug could spell trouble for those who need it.

"People rely on this medication," Fox said. "They have chronic illnesses, and they really rely on this. Once you're stable on these therapies, it's not something that is easy to switch."

India's ban on exports will likely increase prices of the medication short-term and limit supply in the long run, Bloomberg reported. The ban is aimed at ensuring the country has enough access to the drug for its own citizens, according to the report.

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