Desmodium molliculum, known as "manayupa" in traditional Peruvian medicine, has been used for various ailments including inflammation, wound healing, and as a general detoxifying agent. There are ethnobotanical records suggesting that traditional healers sometimes use Desmodium molliculum preparations to alleviate digestive complaints, which may include nausea and vomiting, often as part of broader treatments for gastrointestinal discomfort or liver support. However, these uses are largely based on anecdotal evidence and the plant’s reputation for “cleansing” the system rather than targeted antiemetic effects.

Scientifically, there is currently a lack of direct research or clinical trials investigating the efficacy of Desmodium molliculum specifically for nausea and vomiting. Most published studies have focused on its anti-inflammatory, antimicrobial, and antioxidant properties. No bioactive compounds within the plant have been definitively linked to antiemetic activity. Thus, while there is traditional precedent for its use in general digestive support, the evidence does not robustly support its efficacy for nausea and vomiting beyond historical and cultural practices.

In summary, the use of Desmodium molliculum for nausea and vomiting is justified primarily by tradition, with very limited direct evidence and no strong scientific validation at this time.