Peptides are chains of amino acids that are shorter than proteins (this is why you may hear them referred to as ‘short proteins’). In the world of health and fitness, people take peptides to increase energy, burn fat, build muscle, improve athletic ability, rejuvenate the body and provide treatment for certain disorders. Due to their small chain size, peptides are easy for the body to break down and absorb. They come in many different forms and can produce numerous physical and mental benefits.