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Researchers found that smiling changes how key skin features like wrinkles, texture, and pore visibility show up in selfies, which can skew the results from skin-analysis apps. Basically, a smile stretches and compresses your skin in patterns that look like different conditions than you actually have. So for the most accurate snapshot of your skin, keep a neutral face.
Evidence Assessment
Evidence Strength
Moderate
Study Type
Experimental study of facial expression effects on skin image analysis
Confidence
Medium
Key Findings
- Smiling significantly alters how skin features like wrinkles, pores, and texture appear in selfies.
- Facial expression can introduce enough variation to mess up direct comparisons between skin scans over time.
- A neutral expression appears to be the most reliable baseline for smartphone-based skin analysis.
Practical Takeaways
- When using a skin-analysis app, take your selfie with a completely relaxed, neutral face — no smile, raised brows, or squinting.
- Take multiple selfies in the same lighting at the same time of day, and always use the same expression, to get more consistent tracking.
Limitations & Caveats
- This is a single study, and the results may not hold equally across all skin types, camera hardware, or app algorithms.
- The research focused on still selfies; real-world conditions like lighting and angle could interact with expression effects in ways not fully captured.