Breakthrough to Strengthen Bones Could Reverse Osteoporosis

Health, 12 March 2026

By David Nield

An illustration of osteoporosis. (Science Photo Library/Brand X Pictures/Getty Images)

Research points to a key bone-strengthening mechanism at work in the body, which could be targeted to treat the bone-weakening disease, osteoporosis.

Led by scientists from the University of Leipzig in Germany and Shandong University in China, the 2025 study identified the cell receptor GPR133 (also known as ADGRD1) as being crucial to bone density, via bone-building cells called osteoblasts.

Variations in the GPR133 gene had previously been linked to bone density, leading researchers to turn their attention to the protein it encoded.

The team ran tests on mice in which the gene was either absent or could be activated using a chemical called AP503.

In the absence of the GPR133 gene, the mice grew up with weak bones, resembling the symptoms of osteoporosis. However, when the receptor was present and activated by AP503, bone production and strength improved.

Watch the video below for a summary of the findings:

“Using the substance AP503, which was only recently identified via a computer-assisted screen as a stimulator of GPR133, we were able to significantly increase bone strength in both healthy and osteoporotic mice,” said University of Leipzig biochemist Ines Liebscher when the results were announced last year.

In these experiments, AP503 serves as a biological button that gets the osteoblasts working harder. The researchers were also able to show that it could work in tandem with exercise to strengthen bones even further.

Knowing that the GPR133 cell receptor is a crucial link in maintaining strong mouse bones is an important finding. While the results are based on an animal model, the underlying processes are likely similar in humans.

“If this receptor is impaired by genetic changes, mice show signs of loss of bone density at an early age – similar to osteoporosis in humans,” says Liebscher.

Osteoporosis is a serious condition affecting millions worldwide. While available treatments can slow the condition’s progress, there’s no way to reverse or cure the condition.

Current treatments also tend to come with risky side effects (like an increased risk of other diseases) or become less effective over time.

There are actually numerous factors that have an influence on bone strength, and that gives scientists plenty of scope for finding methods that ward off issues like osteoporosis and promote a healthier old age.

Continue/Read Original Article: Breakthrough to Strengthen Bones Could Reverse Osteoporosis : ScienceAlert