Objective: To observe the efficacy and safety of Yigu capsule (YGC)

a Chinese herbal compound preparation

in treating postmenopausal osteoporosis (PMO) and to explore its possible mechanism.Methods: The clinical study was conducted in a prospective

randomized

double blinded method lasting for 6 months with placebo and positive control. Two hundred and ten PMO patients with confirmed diagnosis were assigned into the YGC group

the calciferol group and the placebo group. Besides being administered element calcium

they were treated with YGC

calciferol capsule and placebo capsule respectively. And such symptoms as newly found fracture and ostealgia

bone mineral density (BMD) of the 2nd–4th lumbar vertebrae (L2–4) and upper femur

blood and urinary indexes for bone metabolism

sex hormone level and adverse reaction that occurred in patients were observed.Results: In the YGC group

the total effective rate was 95. 50%

with no new occurrence of fractures

which was significantly better than that in the other two groups (P<0.05). Moreover

in the YGC group

the increase rate of BMD was 9.83% in L2–4

4.09% in femoral neck

4.60% in Wards triangle

3.00% in greater trochanter

which was also better than that in the placebo group (P<0.05

P<0.01). As compared with the placebo group

levels in the YGC group of urinary oxyproline hydroxyproline/creatinine

urinary calcium/creatinine were significantly lower

serum and bone alkaline phosphatase

osteocalcin

estradiol and estradiol/testosterone were significantly higher

but no difference was shown in the comparison of testosterone level. In the observation period

no abnormality in blood or urine routine

liver or renal function was found. Only mild

transient gastro-intestinal response occurred in individual patients

but it did not affect the treatment.Conclusion: YGC could treat PMO effectively

as it could obviously increase the BMD of lumbar vertebrae and coxafemoral bone

elevate the alleviating rate of ostealgia and incessant motion time

yet causing no newly found compressive fracture of vertebrae

or and any related adverse reaction. YGC could not only promote the formation

but also inhibit the absorption of bone as well as increase the sex hormone level. Therefore

it is a pure Chinese herbal compound preparation worthy of further research and development.