Estrogen replacement therapy (ERT) is the main treatment postmenopausal osteoporosis. However, ERT causes serious side effects, such as cancers and thromboembolic problems. Labisia pumila var. alata (LPva) is a herb with potential as an alternative to ERT to prevent complications of osteoporosis, especially fragility fractures. This study was conducted to determine the effects of LPva on the biomechanical strength of femora exposed to osteoporosis due to estrogen deficiency, using the postmenopausal rat model. Thirty-two female rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LP), and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via oral gavage daily at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized, and their right femora were prepared for bone biomechanical testing. The results showed that ovariectomy compromised the femoral strength, while LPva supplementation to the ovariectomized rats improved the femoral strength. Therefore, LPva may be as effective as ERT in preventing fractures due to estrogen-deficient osteoporosis.