For more than 500 years, Leonardo da Vinci's Mona Lisa has fascinated the world with her enigmatic smile. Yet one detail continues to intrigue art lovers: why does the celebrated portrait appear to show a woman without eyebrows or eyelashes? A new medical theory has revived the debate, but the explanation could lie in Renaissance beauty standards or changes to the painting over time.
Italian dermatologist Dr Luigi Laino has suggested that the woman widely identified as Lisa Gherardini may have suffered from alopecia areata universalis, a condition associated with extensive hair loss. However, this remains a retrospective hypothesis, not a confirmed diagnosis. Historical grooming practices and the possible disappearance of painted details offer alternative explanations for her distinctive appearance.
Could the Mona Lisa Have Had Alopecia?
In a paper published online on 24 August 2026 in Clinics in Dermatology, Laino argued that several features of the portrait could be consistent with alopecia areata universalis, an autoimmune condition that can cause hair loss across the scalp and body, including the eyebrows and eyelashes.
He pointed to the apparent absence of eyebrows and eyelashes, the hairline and the skin around the forehead and eyes. Laino wrote: 'Of all available explanations, only alopecia areata universalis accounts for all four.'
The condition varies in severity, and its effects can range from small patches of hair loss to the extensive loss associated with alopecia universalis. However, a painting cannot provide the medical history or clinical examination needed to diagnose someone who lived centuries ago.
Discussions of the theory have also cited Gherardini's reported personal hardships. Although stress may be associated with some cases of alopecia, there is no evidence establishing that she had the condition or that personal tragedy caused her to lose her hair.
Did Renaissance Beauty Rules Explain Her Bare Brows?
A medical condition is not the only possibility. In medieval and Renaissance Europe, some women removed facial hair and plucked their eyebrows to achieve fashionable looks, while a high forehead was also considered desirable in certain periods.
Historical scholarship has documented depilation practices in late medieval Europe. The Metropolitan Museum of Art has also explored the Renaissance ideal of a high forehead, which could be accentuated by removing hair along the hairline.
These customs make deliberate grooming a plausible explanation for the Mona Lisa's appearance. However, there is no definitive evidence that Gherardini plucked her eyebrows or that Leonardo da Vinci intentionally depicted her following a particular beauty trend.
Could Her Eyebrows Have Disappeared Over Time?
A separate theory emerged in 2007, when French engineer Pascal Cotte presented findings from advanced imaging of the painting. According to contemporary reports, his multispectral scans revealed what he interpreted as a single hair in the area of the Mona Lisa's left eyebrow.
Cotte suggested that eyebrow details might once have been more visible but had faded or been removed during cleaning or restoration. His findings raised the possibility that the portrait's apparently bare brows do not reflect its original appearance.
However, the imaging does not conclusively establish what the original eyebrow looked like or why it is now difficult to see. Laino offers a different interpretation, arguing that the reported hair could reflect incomplete hair loss rather than proof that a painted eyebrow has vanished.
The competing explanations highlight a central challenge in studying historic portraits: a feature that appears to reveal something about a sitter's health may instead reflect artistic choices, beauty practices or the painting's condition.
Why the Mystery Still Matters
The Mona Lisa has inspired numerous retrospective medical theories, including suggestions involving thyroid disease. Such proposals can be intriguing, but they remain interpretations rather than established diagnoses.
Her eyebrows also offer a window into changing beauty standards. Features considered unusual today may once have been fashionable, while details that appear to indicate a medical condition may reflect an artist's technique or centuries of ageing and restoration.
At present, no definitive answer explains why the Mona Lisa appears to lack eyebrows and eyelashes. Alopecia, Renaissance grooming practices and the possible loss of painted details remain competing explanations. More than five centuries after Leonardo da Vinci created his celebrated portrait, a seemingly small detail continues to raise bigger questions about art, medicine and the history of beauty.
