To evaluate the safety and efficacy of Tien-Hsien Liquid Practical (THL-P), a Chinese herbal mixture, in patients with refractory metastatic breast cancer, we performed a randomized, double-blind, placebo-controlled, parallel-group, phase IIa pilot trial. Patients were randomly assigned to either receive THL-P or matching placebo and followed up every 4 weeks for 24 weeks. The primary endpoint was changes in the global health status/quality of life (GHS/QOL) scale. The secondary endpoints were changes in functional and symptom scales, immunomodulating effects, and adverse events. Sixty-three patients were enrolled between June 2009 and June 2011. The intent-to-treat population included 28 patients in the THL-P group and 11 patients in the placebo group. Compared to the placebo group, the THL-P group had significant improvement from baseline to last visit in GHS/QOL (41.7 versus −33.3; P<0.05), CD3, CD4/CD8, CD19, CD16+56 positive cells (P<0.05), and higher levels of physical, role, emotional, and cognitive functioning, as well as decreased fatigue and systemic side effects. Treatment-related adverse events were mild constipation and localized itching, and no serious adverse events were reported. THL-P appears to be a safe alternative adjuvant treatment for patients with refractory metastatic breast cancer, as it effectively improves QOL and palliates cancer-related symptoms.