The scientific story of hCG begins in the 1920s, when German gynecologist-researchers Selmar Aschheim and Bernhard Zondek observed that urine from pregnant women, when injected into immature female mice, triggered ovarian changes that did not occur with urine from non-pregnant women. They correctly reasoned that a substance unique to pregnancy was responsible, even though the hormone itself had not yet been isolated or named.
This became known as the Aschheim-Zondek test, and it represented the first practical biological pregnancy test, replacing guesswork and clinical symptom-watching with an actual laboratory assay, even though it required days to complete and depended on live animals.
Over the following decades, researchers worked to purify and characterize the active substance responsible for the Aschheim-Zondek effect. It was eventually isolated, named human chorionic gonadotropin to reflect both its placental origin and its gonadotropic action, and its two-subunit glycoprotein structure was gradually mapped out through mid-century biochemistry.
That structural work, completed well before the genetic engineering era, laid the foundation for everything that followed: understanding why hCG shares a receptor with luteinizing hormone, why it behaves the way it does in the body, and eventually how it could be manufactured outside the human body altogether.
Mid-century endocrinologists also began cataloguing where hCG deviated from its molecular relatives, work that eventually explained why certain tumors could produce hCG outside of pregnancy entirely, a finding that later became clinically useful in oncology and is discussed in our article on hCG as a tumor marker in testicular cancer.
As endocrinology matured through the mid-twentieth century, physicians recognized that a hormone capable of mimicking luteinizing hormone had therapeutic uses beyond pregnancy detection. It became a tool for triggering ovulation in fertility treatment and for stimulating testosterone production in men with certain forms of hypogonadism, uses that are still current in clinical fertility medicine today.
This shift from purely diagnostic marker to prescribed therapy is what placed hCG under pharmaceutical regulation in virtually every country with a modern health system, a status explored in our overview of hCG regulation under the UAE Ministry of Health and Prevention.
For most of the twentieth century, therapeutic hCG was purified from the urine of pregnant women, a manufacturing method that remains in use in parts of the world today. Advances in recombinant DNA technology later allowed hCG to be produced in laboratory cell cultures instead, without relying on urine collection at all.
The differences between these two manufacturing approaches, and why regulators require rigorous purity and quality standards for both, are covered in more depth in our article comparing recombinant and urinary hCG production.
Alongside its legitimate clinical history, hCG also acquired a persistent, medically unsupported reputation in weight-loss circles during the mid-twentieth century, a claim examined and debunked in our dedicated article on the hCG diet.
This article is provided for general historical and educational context. REVIVE LAB UAE supplies non-prescription research peptides and does not sell, stock, or supply hCG in any form.