In order to understand how OGF works, it is crucial to briefly introduce the workings of the ‘natural opioid’ (endorphin) system.

Endorphins are opiate-like molecules produced naturally in the body. The term ‘endorphin’ comes from ‘endogenous morphine’, meaning that it is created within the body, and differentiating it from opioids that are administered from external sources.

Endorphins are produced in most cells in the body, and are important regulators of cell growth and therefore the immune system. Disorders of the immune system can occur with unusually low levels of these endorphins. The particular endorphin that has been found to influence cell growth as well as immunity is called Opioid Growth Factor (OGF) or Met-Enkephalin.

For an endorphin such as OGF to exert its beneficial effects, it must interact with the body’s cells. It does this by binding to a receptor on the surface of the cells. The receptor to which OGF binds is the ‘Opioid Growth Factor Receptor’ (OGFr) – previously known as the Zeta (ζ) receptor.

Thus, for the endorphin system to be fully functional, two elements are required: opioid production and cell interaction.

In certain cases of cancer, there is insufficient production of OGF in order to control cancer cell growth. In such situations, the cells may produce additional receptors in order to try and capture whatever circulating OGF is available. In these cases, administering OGF provides the missing key which then activates the OGF receptors (OGFr) on cancer cells and slows their growth.

In other cases, there is sufficient production of OGF, but the production of OGF receptors (OGFr) is insufficient to allow cells to capture the high levels of circulating OGF and use it to slow down cell growth. The reason for the failure of production of OGF receptors (OGFr) is not yet clear. However, even cases such as pancreatic cancer where the inability to produce OGF receptors gradually increases, it has been shown that injecting OGF to patients can dramatically slow cell growth and prolong survival.

Unlike chemotherapy, OGF does not directly destroy cancer cells and is not cytotoxic. It does, however, slow down the growth of the cells and is thought to allow immunological mechanisms (e.g. macrophages, natural killer cells) to accomplish the task of destroying the cancerous cells.

OGF also appears to work in harmony with chemotherapeutic agents. When given in combination with OGF, chemotherapy is likely to work in a more efficacious manner.