Science says what you’re thinking: overfilled lips are not beautiful

Image C is considered the most ideal in terms of overall lip volume, featuring an upper lip height equal to 25 percent of the hemi-lip width. Captured from Plastic and Reconstructive Surgery – Global Open

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As lip filler procedures grow in popularity, more patients are pursuing exaggerated enhancements, often influenced by social media trends. But new research has found that natural proportions — not overinflated lips — are considered most attractive.

A research team from the American University of Beirut used artificial intelligence to generate images of a White female face with various upper-to-lower (U/L) lip ratios and degrees of lip fullness. In a survey of 200 adults, participants ranked these images based on perceived attractiveness. The study was published in the international journal Plastic and Reconstructive Surgery – Global Open.

The most aesthetically preferred lips were those with a U/L ratio between 0.618:1 and 1:1, meaning either a slightly fuller lower lip or a balanced upper and lower lip. Upper lips that measured 25 percent of hemi-lip width received the highest ratings. In contrast, images with overinflated lips — especially when both lips were enlarged or the upper lip exceeded 30 percent of hemi-width — were consistently rated as unaesthetic and unnatural.

The researchers noted that full lips have long been considered a hallmark of youth and beauty and that lip augmentation with soft tissue fillers is now one of the most common nonsurgical aesthetic procedures. However, their findings suggest that augmentation beyond natural proportions may reduce — rather than enhance — perceived attractiveness, the researchers stressed.

The study also reflects growing concerns over beauty ideals shaped by celebrity culture and social media. As aesthetic procedures become more normalized — often compared to getting a haircut or a manicure — more patients are bringing in reference photos of influencers or celebrities, hoping to achieve dramatic results.

But the researchers caution that social media alone does not fully explain this trend.

“Exaggerated requests of some patients may not be attributed solely to social media influence,” the study said. “They are likely the result of social media in combination with additional underlying personal predisposing factors,” including body image distortion and psychological tendencies such as perfectionism or neuroticism.

What makes the study particularly notable is its AI-based methodology, which sought to quantify aesthetic preferences using systematically varied images. Participants consistently favored lips that appeared balanced and harmonious over those that were excessively filled.

The authors concluded that the objective of lip augmentation is not merely to “increase volume” but to achieve proportion and harmony that suit each individual’s facial structure. They emphasized that practitioners should counsel patients thoroughly to align expectations with natural standards of beauty rather than chasing passing trends.

This article from Kormedi.com, Korea’s top healthcare and medical portal, is translated by a generative AI system and edited by The Korea Times.