Table 3.

Comparative effects of oral versus transdermal estrogens

	Oral estrogen	Transdermal estrogen
Pharmacokinetics	Serum level peaks and troughs	Serum level remains relatively constant
Inflammatory markers (eg, C-reactive protein)	Increased synthesis	Neutral
Lipid effects	Increased triglycerides Increased HDL Decreased LDL	Decreased triglycerides Neutral effects on HDL and LDL
Blood pressure	Increased	Decreased
Insulin-like growth factor 1	Decreased (may lead to decreased lean body mass and increased body fat)	Neutral
Sex hormone-binding globulin	Strongly increased	Minimally increased
Clotting protein synthesis (hepatic enzyme induced)	Increased (may increase risk of venous thromboembolism)	Neutral (no increase in risk of venous thromboembolism at low doses)

Note: Data from Goodman.⁶⁴

Abbreviations: HDL, high-density lipoprotein; LDL, low-density lipoprotein.