This is an investigator initiated academic clinical study. This will be a prospective, randomized, two-arm, active-controlled, parallel, open label clinical study to assess the efficacy and safety of nandrolone decanoate, alendronate, as compared to alendronate alone in patients with osteoporosis. A minimum of 220 patients with osteoporosis with T score ≤ - 2.5 (WHO) would be enrolled at a single centre. The enrolled patients would be assigned to either of the 2 study groups according to the centralized computer generated randomization in a 1:1 (test: reference) ratio.  The eligible patients will then be enrolled and randomized to either of the study groups as per their randomization number on baseline visit (visit 2, day 0). After randomization, patients will then be followed up on an outpatient basis with scheduled visits at month 6 (visit 3) and month 12 (visit 4) for clinical evaluation and answering questionnaires. Enrolled patients will receive either of the study drugs as per their randomization number. In the test arm, nandrolone decanoate 50mg i.m. every 3 weeks for 12 weeks and then every 4 weeks for another 36 weeks. Alendronate 70mg po once a week for a period of 48 weeks.

In the control arm, subjects shall take alendronate 70mg once a week for a period of 48 weeks. Patients will be given calcium 1000 mg/day (in divided doses) along with vitamin D 400 IU/day (in divided doses). Laboratory investigations to be done at screening visit (visit 1), visit 3 (month 6) and visit 4 (month 12) & DXA (Dual energy X-ray absorptiometry) to be done at screening visit (visit 1) and visit 6 (month 12). This will be a parallel group study and all the enrolled patients will be provided the study medications for a treatment period of 12 months.

Efficacy parameters:

·         Difference from baseline in BMD/T score (DXA) ward’s triangle, one vertebra femoral neck, hip, greater trochanter, distal 1/3rd radius at the end of the study in the two groups

·         Difference from baseline Lean body (muscle) mass and fat mass using DXA in the two groups

·         Change from baseline in the intensity of bone pain (VAS) at the end of the study in the two groups

·         Change from baseline in the quality of life score in the two groups

·         Change from baseline in the Oswestry Low Back Pain Disability Questionnaire score at the end of the study in the two groups.

Safety endpoints:

·         Adverse events reported during the study

·         Serious adverse events reported during the study

·         Overall tolerability evaluation at the end of study in the two groups