Peptide injections are being hyped as shortcuts for faster healing and muscle recovery. We spoke with a doctor who says the science behind these popular products is still shaky, and many haven't People are turning themselves into lab rats': the injectable peptides craze sweeping the US Well actually The Guardian Peptides are surging in popularity. There's little evidence that they work. They Call It the 'Wolverine Peptide.' And Everyone from Biohackers to Your Dad Wants It Now.