The quick answer
Many people assume "vaginal" means "local only" — that hormones applied vaginally just stay put and don't reach the bloodstream. That's not how the vaginal route actually works. Whether a vaginal hormone product acts locally or systemically depends on the dose and formulation, not the route itself.
Why the vaginal route can deliver hormones into the bloodstream
The vaginal wall is richly supplied with blood vessels and drains into pelvic veins that lead directly into general circulation - not through the liver first, the way a swallowed pill does. This matters because the liver breaks down a large portion of oral hormones before they ever reach the rest of the body. Vaginal delivery skips that step.
This isn't a new or unusual idea, it's the same principle that lets a contraceptive vaginal ring reliably prevent pregnancy in millions of users worldwide. That only works because the contraceptive is reaching the bloodstream consistently, at real, biologically active levels.
Why some studies say "vaginal isn't systemic"
Many well-known vaginal estrogen studies are about very low-dose products designed specifically for local vaginal dryness, not for whole-body symptom relief. Those products are intentionally formulated to minimize how much reaches the bloodstream. When those studies report "low systemic absorption," they're describing a product built to do exactly that - it does not prove that the vaginal route itself is incapable of systemic delivery.
Oestra® is formulated differently: at doses intended for systemic, whole-body effect.
What we've observed in our own patients
Across our patient dosing data, both estradiol and progesterone rise in a clear, dose-dependent way - and the body's own hormone signals (FSH and LH) respond accordingly, which is exactly what we'd expect if the hormone is genuinely reaching circulation:
Marker | Lower dose | Higher dose |
Estradiol | Lower | Meaningfully higher |
Progesterone | Lower | Meaningfully higher |
FSH / LH | Higher | Lower |
We don't yet have a dedicated, published pharmacokinetic study establishing an exact absorption percentage for Oestra specifically, and we won't state one until we do - but this pattern is consistent with real systemic absorption, not just local effect.
If your doctor is skeptical
This is a genuinely common and understandable question - many providers were trained primarily on low-dose local vaginal products, so "vaginal = local only" is often the default assumption. It's not a sign your doctor doesn't know what they're doing; it's a knowledge gap in an area that gets far less attention than oral or transdermal hormone therapy.
A note on history: Oestra® was developed by Dr. Daccarett through direct clinical practice starting approximately eight years ago, and has been refined since. Inner Balance was founded in 2023, and has since treated over 60,000 women. This reflects real, ongoing clinical experience - though it's not a substitute for the dedicated research we're continuing to pursue, and we don't present it as proof on its own.
We've prepared a companion clinical reference document you're welcome to share with your provider, with citations, if you'd like to have that conversation together.
This handout is educational and does not replace individualized medical advice. Talk to your Inner Balance clinician if you are a patient, or another provider about any questions specific to your care.