The Threads social media app launched on 5th July. Instagram users were able to sign up with just a few clicks. It joins a plethora of other social media apps like Snapchat, Twitter and TikTok, all of which are readily accessible on our phones. With all these apps at our fingertips, it’s never been easier for us to discover new people to follow, keep in touch with our friends and stay up to date with the latest news about our favourite celebrities. But Professor Devi Sridhar, the chair of global public health at the University of Edinburgh, is concerned about the harmful effect that all these apps could potentially be having on the health of young people. She talks to Marnie Chesterton about why they should be better regulated in order to protect our children. Marnie is then joined by Professor Andrew Przybylski from the University of Oxford who says that more studies need to be carried out. Next up we find out more about phages – ‘good’ viruses that infect and destroy bacteria and could hold the key to fighting disease. Tom Ireland, author of a new book, The Good Virus, tells Marnie about the history of phages and their potentially exciting future. This week the European Court of Human Rights ruled in favour of middle-distance runner and Olympic champion Caster Semenya in a case related to testosterone levels in female athletes. Marnie speaks to developmental biologist Dr Emma Hilton about what causes differences in sexual development and the impact they can have. We also hear from Dr Stuart Farrimond who explains how the microclimates in your garden can affect the plants you can grow. Presenter: Marnie Chesterton Producer: Harrison Lewis Content producer: Alice Lipscombe-Southwell Assistant producer: Robbie Wojciechowski Editor: Richard Collings