The retinol formula increased skin’s firmness Collagen Cream by 24% after four weeks of use in calculations with the Cutometer, which was one of the highest measurements in our test of anti-aging serums. It also excelled in lifting, brightening and softening skin, thanks to potent anti-aging ingredients like retinol, niacinamide and peptides. This GH Beauty Lab night cream test winner from Olay offers incredible value, boosting skin firmness by 27% in four weeks, as measured by the Lab's Cutomet...