What is the daily abdominal injection drug that begins with T for osteoporosis and what is its risk profile for someone who has never broken a bone

The drug is teriparatide (brand name Forteo), a daily injection of a parathyroid hormone fragment. For someone who has never broken a bone, the risk-benefit calculus is very different than for someone with a prior fracture.

The key evidence comes from a 2001 trial of 1,637 postmenopausal women that showed teriparatide 20 mcg daily cut new vertebral fractures by about 65% (risk ratio 0.35) and nonvertebral fractures by about 35% [2]. But those women already had osteoporosis and many had prior fractures. A 2026 meta-analysis of 24 trials found that bisphosphonates and non-bisphosphonates (including teriparatide) reduce subsequent fracture risk by 40-60% in women who already had a fracture [1]. That is a different question than preventing a first fracture.

For someone who has never broken a bone, the absolute risk of a fracture in the near term is low. The drug's known harms include hypercalcemia (elevated blood calcium) in 11% of patients on the 20 mcg dose, compared to 2% on placebo [2]. A case report documents an 82-year-old man who developed hypercalcemic encephalopathy (confusion, weakness, drowsiness) after just 10 days of teriparatide combined with calcium and vitamin D supplements [3]. The drug is also expensive, requires daily injections, and carries a boxed warning about a risk of osteosarcoma in animal studies.

The evidence does not contain a single trial that tested teriparatide in people without prior fractures and measured whether it prevents first fractures better than doing nothing. The entire evidence base is built on people who already broke bones. For someone who has never broken a bone, the benefit is unproven and the harms are real.

My call: teriparatide is not worth the cost, the daily injections, or the calcium-related risks for someone who has never broken a bone. Confidence: high.