Can you use retinol and vitamin C together?
No trial tests retinol and vitamin C as a pair. Dermatology sources say use a retinoid at night, sunscreen by day, and add one new product at a time.
Articles
Reads on whether your skincare is actually working, how to measure it, and what the tools that claim to tell you get right and wrong.
What can a skincare app tell you that a Yuka score can't?
An ingredient score reads one label. It is not a record of your face. With Oleah you add the products on your shelf and take a morning face scan.
How to know if skincare is working
Compare one change against a repeatable morning record. Skin has no single turnover number. For acne treatments, the AAD says give it 4 to 6 weeks.