Petiveria alliacea, commonly known as "guinea hen weed" or "anamu," has a long history of traditional use in various cultures, particularly in the Caribbean, Central, and South America. In ethnomedicine, Petiveria is used for a range of purposes, including as an anti-inflammatory, analgesic, and for gynecological conditions. Specifically, traditional healers in some regions have employed decoctions or infusions of the root or leaves to help manage afterbirth pain (the uterine contractions that occur after childbirth as the uterus returns to its normal size). The rationale is typically based on the plant's reputed pain-relieving and anti-inflammatory effects, which are believed to help ease discomfort following delivery.

However, while there is some preclinical research suggesting that Petiveria alliacea possesses anti-inflammatory and mild analgesic properties, these studies are mostly in vitro or in animal models, and do not directly address postpartum or afterbirth pain. There is a lack of robust clinical trials or pharmacological studies specifically examining its efficacy for afterbirth pain in humans. Thus, the use of Petiveria for this indication remains primarily rooted in traditional knowledge rather than scientific validation.

References:

• Leandro, L. M., et al. (2015). "Bioactivity of Petiveria alliacea L. (Phytolaccaceae) extracts: a review." Journal of Ethnopharmacology 161: 52-60.
• De Albuquerque, U. P., et al. (2007). "Medicinal plant knowledge of the inhabitants of the 'Vale do Catimbau,' PE, Brazil." Journal of Ethnobiology and Ethnomedicine 3:13.