Japanese drugstores were stripped bare of gargling solution by Wednesday, a day after the governor of Osaka Prefecture suggested it could help fight coronavirus, triggering panicked buying reminiscent of the early days of mask shortages.

Hundreds of thousands of people posted pictures of emptied shelves on Twitter, accompanied by handwritten "Out of Stock" notices, as they canvassed suggestions on how to acquire the coveted antiseptic.

On Tuesday, Osaka Gov Hirofumi Yoshimura said a study showed a smaller viral load in the saliva of 41 patients with mild symptoms after regular gargling with a medicine infused with povidone-iodine solution than in those who had not.

As the Japanese official spoke, shares of Meiji Holdings Co, which sells a popular medicine previously marketed as Isojin, skyrocketed, gaining as much as 7.7% by late on Tuesday.

The shares were down 4% on Wednesday, but more than 1.2 million tweets had employed the hashtag #Isojin by afternoon.