Sold for decades as a medicine that steadies leaky small blood vessels, now placed in facial creams. Measured in people: less facial redness, less stinging and itching, firmer barrier, higher surface water. Nothing measured on wrinkles, firmness, pigmentation or collagen. Almost all skin work came from cosmetic companies, and no facial study compared it against its own base cream. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Transepidermal water loss | Below 10–15 g/m²/h on facial skin | Direct read of barrier integrity; the earliest measure to move |
| Stratum corneum hydration | Above 45–50 arbitrary units on the cheek | Shows whether the formulation holds water in the surface layer |
| Erythema index | No established target; track change from own baseline | The objective counterpart to visible facial redness |
| Sensitive Scale-10 score | Below 30 out of 100 | Captures the stinging and burning that instruments miss |
| Dermatology Life Quality Index | 0–1, meaning no effect on daily life | Tells whether measured change is worth the routine |
| Patch test to the finished product | Negative at 72 and 120 hours | Detects flavonoid or vehicle sensitization before facial exposure |
Cadence: Full set at baseline, then repeated at 2 weeks, 4 weeks and 8 weeks, then every 3 months while use continues.