Research

Hormonal

Transdermal estrogen does not significantly increase the risk of venous thromboembolism in postmenopausal women, unlike oral estrogen.

If you are using transdermal estrogen (patches or gels), your risk of blood clots is not significantly increased compared to women not using hormones. This makes transdermal estrogen a safer choice than oral estrogen for postmenopausal women concerned about thromboembolism, especially those with other risk factors like obesity or genetic mutations.

GoodRefutesMEDIUM confidence
Meta-analysis of observational studies showed that oral oestrogen but not transdermal oestrogen increased the risk of venous thromboembolism... odds ratio... in current users of transdermal oestrogen was 1.2 (0.9 to 1.7).
Marianne Canonico et al. · BMJ · 2008

Why this rating

Based on fewer observational studies for transdermal route compared to oral; no RCTs specifically for transdermal VTE risk were found.

Source

Hormone replacement therapy and risk of venous thromboembolism in postmenopausal women: systematic review and meta-analysis

Marianne Canonico et al. · BMJ · 2008

DOI 10.1136/bmj.39555.441944.be

Meta-analysis · 17 studiesCited 558×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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