Unexpected Risks of Hormone Therapies: A Cautionary Tale
A case that made headlines in a medical journal a few years back has recently resurfaced in the media, shedding light on a surprising danger associated with hormone therapies. The story involves a baby girl in Sweden who developed enlarged genitals after inadvertently being exposed to her father’s testosterone gel while lying on his bare chest.
This incident serves as a stark reminder that while hormone treatments can be safe when used correctly, they also carry risks if proper precautions are not taken.
Testosterone is a potent sex hormone crucial for male development. During the early months of life, babies undergo rapid growth, making their bodies and hormones incredibly sensitive.
Even small amounts of testosterone absorbed through the skin can have a significant impact on a baby’s development, especially with repeated exposure.
During what is known as “mini-puberty,” a brief period of heightened hormone levels that occurs a few months after birth, boys experience a surge in testosterone levels that aid in the completion of their reproductive system development and prepare them for adulthood. This process also plays a role in brain development.
On the other hand, girls experience a slight rise in estrogen levels during this period, while testosterone remains low. Exposure to external testosterone, such as from hormone gel, can lead to unexpected changes in girls, such as an enlarged clitoris or fusion of the labia – as seen in the Swedish case.

Testosterone gels are commonly prescribed to treat men with low testosterone levels. The gel is typically applied once a day to clean, dry skin on the shoulders, upper arms, or stomach. While the gel dries quickly, residue can linger on the skin for an hour or two after application. If someone touches the treated area too soon or comes into direct contact with it, they may unintentionally absorb some of the hormone. This risk is especially significant for babies and young children, whose thinner and more absorbent skin makes them more vulnerable.
It’s worth noting that testosterone gels are also being used off-label in women to address menopausal symptoms, albeit at a much lower dosage than that prescribed to men. However, accidental exposure is still possible, particularly when women come into contact with treated skin shortly after application.
Gaining Perspective
While stories like the Swedish case understandably raise alarm, it’s essential to assess the actual level of risk. In the UK, tens of thousands of individuals are prescribed testosterone through the NHS, with gel formulations being popular due to their ease of use. If accidental exposure were a common occurrence, we would likely see a higher number of reported cases in medical literature.
The instructions accompanying testosterone gels are clear: apply only to designated areas, wash hands immediately, cover the skin once dry, and avoid close skin contact for several hours. When these guidelines are adhered to, the risk of transfer is minimal.
In cases like the one in Sweden, where the father ceased resting the baby on his bare chest, the genital changes reversed over time. Similarly, in other reported incidents, when exposure is halted early, many effects can naturally diminish.
However, in more severe or prolonged situations, children may require medical intervention, such as hormonal tests, ongoing monitoring, anti-hormone treatment, or even surgery if physical changes persist. Prompt action is crucial, underscoring the importance of consulting a healthcare provider if any concerns arise.
For individuals with infants, young children, or pregnant partners at home, careful planning is key. Applying the gel when direct contact is unlikely immediately afterward or exploring alternative administration methods like injections, skin patches, or tablets can reduce the risk of unintentional exposure to others.
While the Swedish case serves as a cautionary tale, it’s important not to fear hormone therapies unnecessarily. When used correctly, testosterone treatment can effectively address diagnosed testosterone deficiencies in men, improving sexual function, mood, and potentially supporting muscle mass, bone health, and metabolism.
If you are prescribed this medication, use it responsibly and follow the instructions diligently to ensure safe and effective treatment.
Daniel Kelly, Senior Lecturer in Biochemistry, Sheffield Hallam University
This article is republished from The Conversation under a Creative Commons license. Read the original article.