Going up and down

Strength is set by how much base you blend into, not by how thickly you apply. Blending 10 mg into 30 mL gives the usual strength; into 15 mL gives a stronger one for a small stubborn area like the lip lines; into 60 mL gives a lighter whole-face serum. Start at the usual strength for the first month, then concentrate it if one area is lagging. A thicker smear of the same cream adds nothing except waste, since the skin only takes up what it can.