Pakistan has recently announced that they plan to abolish the 18% sales tax on menstrual products like pads or tampons. UN Women has welcomed the decision, saying that when these products become more affordable it means more girls and women stay in school and the workforce. For the Unexpected Elements team, the news has led us towards scientific stories of menstruation and different kinds of cycles.

First up, a look at how the menstrual cycle affects drugs reaching the brain and an exploration of one of the only other animals to get a period, the weird and wonderful spiny mouse. Author of A City on Mars, Kelly Weinersmith, also joins us to ponder over what to do when you get your period in space.

Plus, how termite brains change between sexes, why we can’t stop snacking, and the daily battle of the sleep/wake cycle.

All that, plus many more Unexpected Elements.

Presenter: Caroline Steel, with Camilla Mota and Tristan Ahtone