Topical Tranexamic Acid: Does It Reach Your Pigment, or Just Sit on Top?
Tranexamic acid serums promise a lot at 3–5%. Here is what the trials actually measured — and why delivery, not percentage, is the bottleneck.
Why Does Skincare Sting? What That Sting Tells Us — and What It Doesn't
A sting means something reached your nerve endings faster than your skin could buffer it. In one study of 209 healthy women, two-thirds stung on a standard lactic acid test.