Peptides are used in treating viral infections such as hepatitis, HIV, and SARS. Some can target cancer cells by binding to specific tumor markers or mimicking signaling molecules. Others are derived from natural sources to address cardiovascular conditions, offering a wide range of therapeutic potential.

Longer peptides tend to be more difficult to purify and synthesize due to lower yield and stability. In these cases, auxiliary amino acids may be added at the ends to improve solubility and handling. For shorter peptides, typically under five residues, adding hydrophobic amino acids can enhance structural integrity and functionality.

Bioactive peptides are gaining popularity in functional food and nutrition sectors. These peptides can help regulate physiological processes, support immune health, and delay the onset of chronic diseases. Common sources include dairy proteins, plant extracts, collagen, and marine or animal-derived peptides.