Skin Sensitivity
Sensitivity metrics track how your skin responds to products, environment, and stress. When your barrier weakens or your skin becomes more reactive, these scores shift first.
Hydration
How well your skin appears to retain moisture. Dips often correlate with weather changes, barrier weakness, or product gaps.
Redness
Visible redness and flush across your face. Can reflect sensitivity, inflammation, or environmental reactivity.
Surface Oil
Sebum visibility across different zones. Tracks how oil production fluctuates with hormones, weather, and routine changes.
Visible Capillaries
Telangiectasia and visible blood vessels. Often more apparent when the barrier is compromised or after temperature extremes.
PIE (Post-Inflammatory Erythema)
Red marks left after breakouts or irritation. Tracks how quickly these resolve and whether they accumulate.
Clarity and Breakouts
Clarity metrics go beyond counting spots. They track breakout types, location patterns, pore behaviour, and how long your skin takes to recover after a flare.
Skin Clarity
An overall clarity score reflecting breakout activity, congestion, and surface smoothness.
Breakout Types
Distinguishes between comedones, papules, and pustules. Different types suggest different underlying patterns.
Pore Size
Visible pore density and prominence. Often influenced by oil production, exfoliation frequency, and hydration.
Post-Breakout Marks
PIH (pigmented marks) left after breakouts. Tracks whether marks are resolving or accumulating over time.
Breakout Location
Maps where breakouts appear most frequently. Jawline patterns may suggest hormonal factors. T-zone patterns may suggest oil-related congestion.
Tone and Pigmentation
Tone metrics track pigmentation changes across different types: sun-driven, hormonal, and post-inflammatory. They help you see whether dark spots are accumulating, fading, or holding steady.
Pigmentation
Overall pigmentation score reflecting the visibility and spread of dark spots and uneven patches.
Sun Spots
Solar lentigines caused by cumulative UV exposure. Tracks whether new spots are forming and whether existing ones are darkening.
Melasma
Hormonal pigmentation that often appears across the cheeks, forehead, or upper lip. Can fluctuate with cycle, sun exposure, and hormonal changes.
Freckles
Freckle density and visibility. Tracks seasonal fluctuations and long-term changes in distribution.
Skin Tone (ITA)
Your natural skin lightness baseline. Helps contextualise how other pigmentation metrics should be interpreted for your skin.
Aging and Structure
Aging metrics track the gradual structural changes that happen over months and years. Fine lines, deep lines, firmness, and facial contour all shift at different rates depending on your routine, environment, and genetics.
Fine Lines
Early surface lines that often appear first around the eyes and forehead. Hydration and retinoid use can influence their visibility.
Deep Lines
More established static lines visible at rest. These change slowly and are useful as long-term tracking markers.
Nasolabial Folds
The lines running from nose to mouth. Depth can shift with hydration, volume loss, and overall skin laxity.
Marionette Lines
Lines running from the corners of the mouth downward. Often one of the later structural changes to become visible.
Skin Firmness
Overall facial firmness and laxity. Tracks changes in skin tautness and contour definition over time.
Jawline Definition
Sharpness of the jawline contour. Changes in definition can reflect volume loss, laxity, or weight fluctuation.
Perceived Age
An AI estimate of how old your skin appears. Useful as a directional signal, not a precise measurement.
Eye Area
The periorbital area is among the thinnest skin on your body. It shows the effects of sleep, hydration, stress, and aging faster than almost any other region. These metrics help you see what's changing around your eyes over time.
Dark Circles
Darkness beneath the eyes from pigmentation, vascular visibility, or shadowing. One of the most responsive metrics to sleep quality.
Puffiness
Swelling beneath the eyes from fluid retention. Often fluctuates with sleep position, salt intake, and allergies.
Under-Eye Bags
Fat pad visibility beneath the eyes. Tends to change gradually and is influenced by genetics and volume changes.
Under-Eye Hollows
The depth of the tear trough. Becomes more visible with volume loss and can cast shadows that mimic dark circles.
Baseline Properties
Baseline metrics capture your skin's inherent characteristics: natural oiliness, hydration tendencies, and tone. These don't change dramatically, but understanding them helps you interpret everything else Stella tracks.
T-Zone Oil Balance
Natural oil production across the forehead, nose, and chin. Your T-zone baseline informs whether oil-related changes are normal variation or new patterns.
U-Zone Hydration
Hydration patterns across the cheeks and jawline. The U-zone is typically drier and responds differently to products and environment than the T-zone.
Melanin Content
Your natural skin tone and how it interacts with light. Helps contextualise pigmentation metrics and informs how your skin might respond to sun exposure and certain actives.