To provide a material in which stabilized PGF2α can be easily obtained, and can be applied not only for medical purposes but also for aquaculture feed, livestock feed, etc. in a simple and versatile manner. Maxa aqueous ethanol extract containing PGF2α.安定化したPGF2αを容易に入手でき、医療用ばかりでなく、養殖用飼料、家畜用飼料等に簡便且つ汎用的に応用できる材料を提供すること。 PGF2αを含有するマクサ水性エタノール抽出物。