Teriparatide (Forteo) is a recombinant form of parathyroid hormone, used in the treatment of some forms of osteoporosis.It is manufactured and marketed by Eli Lilly and Company. Teriparatide is administered by injection once a day in the thigh or abdomen. The recommended dose is 20 μg per day. Teriparatide has an ongoing clinical trial to evaluate its effectiveness in treating the symptoms of osteogenesis imperfecta. Teriparatide should not be prescribed for patients who are at increased risks for osteosarcoma. This includes those with Paget's Disease of bone or unexplained elevations of serum alkaline phosphate, open epiphysis, or prior radiation therapy involving the skeleton. The main risk of teriparatide is an increased risk of osteosarcoma. Because of this risk, it is typically used as second line therapy and even then for no more than two years. Note some very minor side effects: At the first injection, the user may notice a dime-sized circular, light-colored red rash around the injection site. This should not have any itching associated with it, but may on a rare occasion be very slight. Subsequent injections produce no rashes. Since the needle used for injections is of such a small diameter, there is no blood drawn or expelled during the injection, which typically lasts around 5 seconds. There is no pain involved during the injection. Another slight side effect may be minor tiredness that is noticed 1–3 hours after the injection, but only during the first 4 days. After that, the tiredness disappears completely. The tiredness lasts from 30–45 minutes, and may be noticed in the back, upper arms, and upper chest as though some weight had been carried for a brief period of time and then released. The injection should not produce drowsiness or sleepiness, but check with a pharmacist if other medications are taken or planned to be taken. The main risk of teriparatide is an increased risk of osteosarcoma. Because of this risk, it is typically used as second line therapy and even then for no more than two years. Note some very minor side effects: At the first injection, the user may notice a dime-sized circular, light-colored red rash around the injection site. This should not have any itching associated with it, but may on a rare occasion be very slight. Subsequent injections produce no rashes. Since the needle used for injections is of such a small diameter, there is no blood drawn or expelled during the injection, which typically lasts around 5 seconds. There is no pain involved during the injection. Another slight side effect may be minor tiredness that is noticed 1–3 hours after the injection, but only during the first 4 days. After that, the tiredness disappears completely. The tiredness lasts from 30–45 minutes, and may be noticed in the back, upper arms, and upper chest as though some weight had been carried for a brief period of time and then released. The injection should not produce drowsiness or sleepiness, but check with a pharmacist if other medications are taken or planned to be taken.