Gut feeling: A microscopic view of an over-the-counter drug is one of this year's Wellcome Images Awards winners. Loperamide, a spiky sample seen here at 150 microns, is used to treat diarrhea. The drug works by slowing the movement of stool through the gastrointestinal tract, which allows more time for water to be absorbed out of it. Annie Cavanagh, former multimedia manager at University College London's School of Pharmacy, worked with her colleague David McCarthy to create this false-colored micrograph of the crystal group. They have imaged other common drugs, which Cavanagh hopes will spur interest in pharmaceutical studies.
This article was originally published with the title "What Is It?"