👉 Spermidine is a type of amino acid that is found in plants and some animals. It plays a role in protein synthesis, which is the process by which cells build and maintain their structure and function. Spermidine is also involved in the formation of the cell membrane and is essential for many biological processes. In short, spermidine is a type of amino acid that is found in plants and some animals, and it plays a crucial role in protein synthesis and other biological processes.