Paeonia moutan, commonly known as moutan peony, has a long history of use in traditional Chinese medicine (TCM) for various gynecological disorders, particularly menstrual irregularities. In TCM, the root bark of Paeonia moutan (referred to as "Mudanpi") is believed to "clear heat," "cool the blood," and "move blood stasis," making it a popular ingredient in formulas aimed at regulating menstruation, alleviating dysmenorrhea, and addressing amenorrhea or irregular cycles. It is frequently combined with other herbs such as Paeonia lactiflora ("Baishao"), Angelica sinensis, and Ligusticum chuanxiong in classical formulas like Shao Yao San and Gui Zhi Fu Ling Wan, both of which are traditionally used for menstrual issues.

From a scientific perspective, some preclinical studies indicate that compounds in Paeonia moutan exhibit anti-inflammatory, antispasmodic, and blood circulation–promoting effects, which could plausibly affect menstrual symptoms. However, direct clinical evidence in humans specifically linking Paeonia moutan to improved menstrual regularity is limited and inconclusive. Most of the available evidence derives from its longstanding traditional use and the results of multi-herbal formulations, where Paeonia moutan is only one component. Therefore, the justification for its use to treat or support menstrual irregularities is rooted primarily in tradition, with moderate (but not high) support from historical records and some indirect biological plausibility.