精胺（Spermine）是存在于所有真核细胞中的一种多胺类物质。呈碱性，在生理 pH 下以多质子化的形式存在。

荷兰科学家列文虎克早在1678年就已从人的精液中得到了磷酸精胺结晶。

1888年德国化学家 Albert Ladenburg 和 Abel 首先将其称为“精胺”（德文Spermin）。 1926年英国的 Dudley 等与德国的 Wrede 等同时提出了精胺的正确化学结构。

Spermine is a polyamine involved in cellular metabolism found in all eukaryotic cells. The precursor for synthesis of spermine is the amino acid ornithine. It is found in a wide variety of organisms and tissues and is an essential growth factor in some bacteria. It is found as a polycation at physiological pH. Spermine is associated with nucleic acids and is thought to stabilize helical structure, in particular, in viruses.