How does FORSTEO work?

Osteoporosis happens when not enough new bone grows to replace the bone that is naturally broken down.
Gradually, the bones become thin and fragile, and more likely to break (fracture).
In women, osteoporosis is more common after the menopause, when the levels of the female hormone oestrogen fall.
The active substance in FORSTEO, teriparatide, is identical to part of the human parathyroid hormone.
It acts like the hormone, and stimulates bone formation by acting on osteoblasts (bone forming cells).
It also increases the absorption of calcium from food and prevents too much calcium being lost in the urine.
Teriparatide is produced by a method known as 'recombinant DNA technology': the hormone is made by a bacterium that has received a gene (DNA) that makes it able to produce it.
FORSTEO replaces the natural hormone.