Teriparatide
most data
The Dose Guy’s verdictSep 1, 20266 sources
The only anabolic bone drug on this shelf, and it works. Teriparatide builds new bone, not just slowing loss like bisphosphonates, and the fracture-reduction data is the real thing: large trials, hard endpoints, head-to-head wins. The caution is scope. If you do not have osteoporosis or a fracture that needs help, this is not a wellness peptide to explore. It is a pharmaceutical for a medical problem, still framed by a preclinical safety signal that kept it boxed-warned for 18 years.
What it is
The first 34 amino acids of human parathyroid hormone. The trick is the pulse. A continuous flood of PTH dissolves bone, but a brief daily spike stimulates osteoblasts, the cells that build it. That pulsed-anabolic window is the entire pharmacology, and it is why teriparatide is injected once a day rather than given as a slow drip. Approved for osteoporosis since 2002 and with over two decades of clinical use, teriparatide sits in a different class from most of what is on this shelf: a prescription drug with real fracture-endpoint trials behind it.
Where bisphosphonates and denosumab put the brakes on bone loss, teriparatide adds new bone. That distinction matters most in severe osteoporosis, glucocorticoid-induced bone loss, and cases where antiresorptives alone have not been enough.
What the research shows
Deep, long, and built on hard endpoints. Fractures, not just density:
Realistic protocols
20 micrograms sub-q daily, injected in the thigh or abdomen. The original label carried a 24-month lifetime cap and an osteosarcoma boxed warning based on rat studies at high doses over near-lifetime durations. FDA removed both in November 2020 after two decades of human use showed no osteosarcoma signal. Clinicians still default to courses of 18 to 24 months, but use beyond that window is now permitted when fracture risk warrants it. The 40-microgram dose was tested in the original trial and added more side effects without improving fracture reduction, so there is no reason to go above 20.
Run teriparatide alongside adequate calcium and vitamin D, which your clinician will dose. The pen lives in the fridge, and for the first few injections sit or lie down until you know how the blood-pressure dip feels. The sequence matters as much as the drug. Teriparatide builds new bone, but when you stop, that new bone remodels away unless you follow immediately with an antiresorptive, a bisphosphonate or denosumab, to hold what you built. Starting teriparatide after years on a bisphosphonate blunts the spine-density response, so the ideal order is build first, preserve second.
Side effects
Well characterized across large trials and decades of clinical use:
