Aren't they basically the same hormones?
Does HRT prevent pregnancy?
No - and for perimenopausal women this is the point that genuinely matters. HRT doses do not reliably suppress ovulation, and pregnancy remains possible through perimenopause until menopause is actually confirmed.
A woman who switches from birth control to HRT while still perimenopausal may still need contraception alongside - one of several reasons the transition between the two is a planned, clinician-guided step rather than a swap. If you are unsure which side of the transition you are on, perimenopause vs menopause covers the signals.
Why are so many perimenopausal women on birth control?
When do women switch from birth control to HRT?
When the goal changes: from controlling a cycle (and preventing pregnancy) to treating the symptoms of hormone decline. In practice the switch is a judgment call built from your age, your symptoms, your contraception needs and your history - contraceptive doses carry their own considerations as women get older, which is part of why clinicians revisit the question rather than letting the prescription roll on by inertia.
Menopause-focused telehealth providers handle exactly this transition: Midi and Winona both evaluate where you are and what fits next, and our HRT provider comparison maps the options. Before deciding anything, the pros and cons of HRT is the balanced read.
This article is general information, not medical advice.