Will new clinical trials for Covid-19 give remdesivir a second chance?Ben Valsler introduces the broad-spectrum antiviral that didn't quite make it as the Ebola drug it was originally planned to be.

Old drugs sometimes find their way back into the news. The Covid-19 pandemic – and some very high profile backing – has led to malaria drugs chloroquine and hydroxychloroquine hitting the headlines worldwide. Ben Valsler explores both the history and the hype.

Brian Clegg on the popular over-the-counter painkiller, developed by a high-street pharmacy chain

Catherine Hodges explores the chemical solutions to thinning hair and patchy beards, examining the popularity of minoxidil and the cautionary tale of finasteride

The pesticide that keeps pets free of pests, but may have also been responsible for the devastating collapse of bee colonies. With Harriet Brewerton.

Rotund rodents revolutionised our understanding of the biological role of fat. Now, as Katrina Krämer discovers, the hormones created by fats could redefine obesity.

Ben Valsler on vitamin K – the blood clotting factor that is likely to be the first supplement you ever receive

Brian Clegg on the enzymes make life a little sweeter by breaking down starch into sugars, helping to make bread and beer

Georgia Mills on a compound that explodes from a beetle's bum, and has a controversial role in skin depigmentation

This week marks the 20th anniversary of the Baia Mare disaster, when toxic sodium cyanide spilled from a gold processing plant led to ecological damage on a huge scale. Mike Freemantle tells the tragic tale and explores the poison's place in precious metal processing.