Paeonia moutan (commonly known as moutan peony or tree peony) has a long history of use in traditional Chinese medicine (TCM) for the treatment of menstrual disorders, including dysmenorrhea (painful menstruation). In TCM, Paeonia moutan is often included in classical herbal formulas such as Shao Yao San and Dang Gui Shao Yao San, where it is believed to "cool the blood," "dispel stasis," and alleviate pain associated with menstruation. Its use for dysmenorrhea is primarily based on empirical evidence accumulated over centuries rather than modern clinical trials.

Scientific validation for this specific indication is limited. While some preclinical studies on extracts of Paeonia species (including Paeonia lactiflora and Paeonia moutan) suggest anti-inflammatory, analgesic, and antispasmodic effects—mechanisms relevant to dysmenorrhea—controlled human clinical trials directly examining Paeonia moutan for dysmenorrhea are sparse. Most available studies either employ multi-herb formulations or focus on related species, making it difficult to isolate the effect of Paeonia moutan itself.

In summary, the use of Paeonia moutan for dysmenorrhea is predominantly justified by traditional usage, with some supporting pharmacological rationale but limited direct scientific evidence specific to this condition.