How do our hormones impact our eating habits and will scientists ever make a diet pill? Plus, the tale of the Labradors and the impossible sausage.

We all know what it's like to feel stressed, perhaps this year more than most, but what are our stress hormones really doing to our minds and bodies?

Vitamin D, the hormone in disguise, is currently in the spotlight as the world's favourite supplement, but is it really all it's cracked up to be?

Doping scandals are a regular feature in sporting events, but how do the hormones involved boost performance and why are they banned? Plus, a short history of doping.

We explore the hormones behind our sleep-wake cycle, how they can get out of sync and why some athletes are totally immune to jet lag.

There are chemicals all around us, but can they interfere with our hormones? Endocrine disruptors have been linked with a number of health problems, so for the final episode in the series we look at where these chemicals are found and whether we should be worried.