In my many years as a journalist, I never thought I would be asking someone how it feels to have trout sperm injected into their face. And yet, here I am. Abby Warnes is lying on a large, black padded chair at a small aesthetics clinic in south Manchester. She winces as a small cannula is delicately inserted into her cheek. "Ouch. Ouch," she exclaims. I should make it clear that 29-year-old Abby is not actually receiving a pure dose of trout sperm. The lower part of her face is being injected