Spanish Needle (Bidens pilosa) is traditionally used in various cultures for managing afterbirth pain, which refers to the uterine cramps experienced by women following childbirth as the uterus returns to its pre-pregnancy size. Ethnobotanical records, particularly from African, Caribbean, and Asian traditional medicine, note the use of Bidens pilosa preparations (such as teas or decoctions) to support postpartum recovery, reduce pain, and aid uterine involution. The rationale for this traditional use is often attributed to the plant’s reputed anti-inflammatory and analgesic properties, as well as its ability to modulate smooth muscle activity.

However, direct scientific validation for the efficacy of Bidens pilosa specifically in treating afterbirth pain is lacking. While some preclinical studies demonstrate that extracts of the plant possess general anti-inflammatory and analgesic effects in animal models, these findings have not been directly translated to postpartum pain or uterine cramping in humans. Additionally, there are no clinical trials or pharmacological studies that specifically evaluate Bidens pilosa for afterbirth pain. Thus, its use for this purpose is justified mainly by tradition rather than robust scientific evidence. The evidence rating reflects the presence of traditional support and a plausible pharmacological basis, but very limited direct scientific evidence for this specific indication.