Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Estrogen-associated blood clots
Medically reviewed by Min Clinic Staff | Updated: January 2026
Estrogen-associated blood clots: Blood clots are occasional but serious side effects of estrogen therapy. They are dose-related, that is, they occur more frequently with higher doses of estrogen.
Estrogen therapy preparations (all of which carry this risk) include:
- esterified estrogens
- esterified estrogens and methyltestosterone
- estradiol
- estrogens (conjugated) and medroxyprogesterone
- estrogens conjugated
The brand names of the estrogen therapy preparations carrying this risk include:
- CLIMARA (estradiol)
- ESTRACE (estradiol)
- ESTRADERM (estradiol)
- ESTRATAB (esterified estrogens)
- ESTRATEST (esterified estrogens and methyltestosterone \)
- MENEST (esterified estrogens)
- OGEN (estropipate)
- PREMARIN (estrogens conjugated)
- PREMPHASE (estrogens conjugated and medroxyprogesterone)
- PREMPRO (estrogens conjugated and medroxyprogesterone)
Cigarette smokers on estrogen therapy are at a higher risk than non-smokers for blood clots. Therefore, patients requiring estrogen therapy are strongly encouraged to quit smoking.