Osteoporosis is rapidly turning into a global epidemic, leading to high rates of morbidity and mortality due to the resulting complications such as osteoporotic fractures in older people. Therefore, this review investigated the findings of clinical trials regarding the effects of medicinal herbs on osteoporosis. To this end, several keywords were used to search for relevant articles indexed in the Institute for Scientific Information and PubMed, including “Osteoporosis” or “Bone loss” AND “medicinal plant” or “phyto*” or “herb*”. Finally, 43 articles were included in the review. There are several mechanisms for anti-osteoporosis effects. Estrogen-like effects, especially soy phytoestrogenic compounds and other herbal compounds and formulations, can enhance bone formation markers, as well as antioxidant and anti-inflammatory capacity, while decreasing bone resorption biomarkers. Therefore, they can be used as complementary medicine for osteoporosis, especially in postmenopausal older women. However, for more reliable evidence, further studies are still needed because most studies have addressed soy, and the number of randomized controlled trials conducted on other herbal drugs is small. The plants possess the androgen-like properties that play an important role in the promotion of bone health. In addition, herbal treatments are supportive and slow-acting and thus such treatments are suggested for prevention and maintenance purposes rather than fast-acting treatments.