Hormone tracking
made wearable
Track estrogen, LH, and progesterone in real-time.
Hormonal health, fertility and longevity on your terms.
Hormone tracking
made wearable
Track estrogen, LH, and progesterone in real-time.
Hormonal health, fertility and longevity on your terms.
Hormone tracking
made wearable
Track estrogen, LH, and progesterone in real-time.
Your hormones shouldn't be the
blind spot.
Your hormones shouldn't be the blind spot.
From daily energy levels to reproductive goals and long-term metabolic health, hormones influence how you feel each day and your lifelong wellness.
From daily energy levels to reproductive goals and long-term metabolic health, hormones influence how you feel each day and your lifelong wellness.
1 in 2
women face
hormonal imbalances
women face hormonal imbalance
1 in 4
women struggle
with irregular cycles
women struggle
with irregular cycles
1 in 8
women have
PMOS & infertility
women have
PMOS & infertility
Hormonal imbalances are linked to higher risk of cardiovascular disease, diabetes, infertility, reduced bone health and earlier cognitive decline.
Hormonal imbalances are linked to higher risk of cardiovascular disease, diabetes, infertility, reduced bone health and earlier cognitive decline.
Your hormones shouldn't be the blind spot.
From daily energy levels to reproductive goals and long-term metabolic health, hormones influence how you feel each day and your lifelong wellness.
1 in 2
women face
hormonal imbalances
1 in 4
women struggle
with irregular cycles
1 in 8
women have
PMOS & infertility
Hormonal imbalances are linked to higher risk of cardiovascular disease, diabetes, infertility, reduced bone health and earlier cognitive decline.
Your body signals every shift.
We just found a better way to listen.
Built for everyday wear.
Built for everyday wear.
Continuous, 24/7 sensing built into an earring-back. Phira turns your favorite earrings into hormonal intelligence. No strips, no blood, no disruption to your day.
Continuous, 24/7 sensing built into an earring-back. Phira turns your favorite earrings into hormonal intelligence. No strips, no blood, no disruption to your day.
Universal fit – works with most earring posts
Universal fit – works with most earring posts
Biosensing – accurate to 0.03°C, continuous 24/7 tracking
Biosensing – accurate to 0.03°C, continuous 24/7 tracking
Set & forget – multi-week battery life, water-resistant
Set & forget – multi-week battery life, water-resistant
Day & night – comfortable to sleep in, discreet for the office
Day & night – comfortable to sleep in, discreet for the office
Satin Champagne
Satin Champagne
Built for everyday wear.
Continuous, 24/7 sensing built into an earring-back. Phira turns your favorite earrings into hormonal intelligence. No strips, no blood, no disruption to your day.
Universal fit – works with most earring posts
Biosensing – accurate to 0.03°C, continuous 24/7 tracking
Set & forget – multi-week battery life, water-resistant
Day & night – comfortable to sleep in, discreet for the office
Satin Champagne
Designed to disappear.
Designed to disappear.
Designed to disappear.
Phira tracks estrogen, LH, and progesterone in real-time.
Prior research with invasive intra-vaginal sensors showed that core body temperature and thermoregulatory patterns shift in real-time with hormonal changes. Phira is designed to capture these signals non-invasively, across your full cycle.
Location
The posterior ear is a clinical-grade site for measuring core body temperature, unlike extremities like the wrist or finger.
The posterior ear is a clinical-grade site for core body temperature, unlike extremities like the wrist or finger.
Precision
Sensors accurate to 0.03°C. Designed to detect subtle thermoregulatory shifts correlated with hormonal changes.
Sensors accurate to 0.03°C. Designed to detect subtle thermoregulatory shifts linked to hormonal changes.
Continuous Sensing
24/7 sensing, capturing the patterns that emerge over time and across the cycle. No blood draws or urine tests.
Daily Insights
Daily updates on your hormones and what that means for your cycle, energy, fertility window, and overall wellbeing.
Daily updates on your hormones and what that means for your cycle, energy, fertility window, & wellbeing.
Track estrogen, LH, and progesterone in real-time.
Prior research with invasive intra-vaginal sensors showed that core body temperature and thermoregulatory patterns shift with hormonal changes. Phira is designed to capture these signals non-invasively, across your full cycle.
Location
The posterior ear is a clinical-grade site for measuring core body temperature, unlike extremities like the wrist or finger
Precision
Sensors accurate to 0.03°C detect subtle thermoregulatory shifts correlated with hormonal changes.
Continuous Sensing
24/7 sensing, capturing the patterns that emerge over time and across the cycle. No blood draws or urine tests.
Daily Insights
Daily updates on your hormones and what that means for your cycle, energy, fertility window & wellbeing.
Figure 1. Our early pilot data showing Phira's novel thermoregulatory feature response – consistent with estrogen, LH and progesterone dynamics across the menstrual cycle.
Built on established science.
Expanding what we know.
The link between hormones and thermoregulation is well documented in literature¹ ². Our peer-reviewed publication from our IRB-approved pilot study is now part of that conversation³, and our expanded clinical study is underway.
¹ Reproductive Hormone Influences on Thermoregulation in Women. Comprehensive Physiology, 2024.
² Prediction of the fertile window using a vaginal biosensor for measuring core body temperature. Gynecological Endocrinology, 2018.
³ Physiological Signal Characterization from an Earring-back Wearable. IEEE EMBC, July 2026.
One platform. Every stage.
Hormonal Health
Get in tune with your body. Understand how your sleep, stress, training, and nutrition affect your cycle and menstrual symptoms. Build habits that put you back in control.
Get in tune with your body. Understand how your lifestyle affects your cycle & menstrual symptoms. Build habits that put you back in control.
Get in tune with your body. Understand how your sleep, stress, training, and nutrition affect your cycle and menstrual symptoms. Build habits that put you back in control.
Fertility
Phira gives you a longer and more accurate window to conceive by detecting the earliest signs of high fertility in real-time, earlier than LH strips.
Phira gives you a longer and more accurate window to conceive by detecting the earliest signs of fertility in real-time, earlier than LH strips.
Phira gives you a longer and more accurate window to conceive by detecting the earliest signs of high fertility, earlier than LH strips.
Longevity
Track the patterns linked to menopause and long-term cardiovascular, metabolic, bone, and cognitive health, so you can make informed decisions for your future.
Track the patterns linked to menopause and long-term health, so you can make informed decisions for your future.
Track the patterns linked to menopause and long-term cardiovascular, metabolic, bone, and cognitive health, so you can make informed decisions for your future.
Built on established science.
Expanding what we know.
The link between thermoregulation & hormones is well documented in literature [1,2]. Our peer-reviewed publication from an IRB-approved pilot study is now part of that conversation [3], and our expanded clinical study is underway.
Figure 1. Our early data showing Phira's novel thermoregulatory feature response – consistent with estrogen, LH and progesterone dynamics across the menstrual cycle.
[1] Reproductive Hormone Influences on Thermoregulation in Women. Comprehensive Physiology, 2024.
[2] Prediction of the fertile window using a vaginal biosensor for measuring core body temperature. Gynecological Endocrinology, 2018.
[3] Physiological Signal Characterization from an Earring-back Wearable. IEEE EMBC, July 2026.
Hormone tracking is just the beginning
Hormone tracking is just the beginning
We are building the first hormonal health operating system to help you understand not just what your hormones are doing, but how your sleep, training, stress, and nutrition shape them cycle after cycle.
We are building the first hormonal health operating system to help you understand not just what your hormones are doing, but how your sleep, training, stress, and nutrition shape them cycle after cycle.
More coming soon.
Built on established science.
Built on established science.
Expanding what we know.
The relationship between hormones and thermoregulation is well documented in literature [1,2]. Our peer-reviewed publication from our IRB-approved pilot study is now part of that conversation [3], and our expanded clinical study is underway.
Figure 1. Our early data showing Phira's novel thermoregulatory feature response – consistent with estrogen, LH and progesterone dynamics across the menstrual cycle.
Figure 1. Our early data showing Phira's novel thermoregulatory feature response – consistent with estrogen, LH and progesterone dynamics across the menstrual cycle.
[1] Reproductive Hormone Influences on Thermoregulation in Women. Comprehensive Physiology, 2024.
[2] Prediction of the fertile window using a vaginal biosensor for measuring core body temperature. Gynecological Endocrinology, 2018.
[3] Physiological Signal Characterization from an Earring-back Wearable. IEEE EMBC, July 2026.
From the women who wore it first.
From the women who
wore it first.
Here's what the women who wore Phira during our pilot study experienced.
Here's what the women who wore Phira
during our pilot study experienced.
Maritza
Pilot study participant
"Before Phira, I didn't even realize how out of tune I was with my body. Wearing it let me notice changes in my cycle and hormones that would've otherwise gone unnoticed, and helped me understand my emotional & physiological shifts so much better. It was never inconvenient, even through constant travel."
"Before Phira, I didn't even realize how out of tune I was with my body. Wearing it let me notice changes in my cycle and hormones that would've otherwise gone unnoticed, and helped me understand my emotional & physiological shifts so much better. It was never inconvenient, even through constant travel."
Maritza
Pilot study participant
"Before Phira, I didn't even realize how out of tune I was with my body. Wearing it let me notice changes in my cycle and hormones that would've otherwise gone unnoticed, and helped me understand my emotional & physiological shifts so much better. It was never inconvenient, even through constant travel."
Sophie
Pilot study participant
"It's exciting to see a wearable designed not just for women's bodies, but for women's lives. As someone who works out a lot, a ring gets in the way of lifting so the earring-back format is a huge win for tracking without losing data."
Hannah
Pilot study participant
"As a woman in STEM, I was excited to be part of a study focused on women's hormonal health, something understudied until recently. The device was comfortable, didn't impact my style, and I had no issues sleeping in it. It is a true wear-it-and-forget-it experience."
Sanjana
Pilot study participant
"It was so comfortable to sleep in, I didn't even feel it, and far easier to integrate into daily life than something visible like a watch or ring. Better data and tools like this help women understand their bodies instead of guessing what's normal."
Sophie
Pilot study participant
"It's exciting to see a wearable designed not just for women's bodies, but for women's lives. As someone who works out a lot, a ring gets in the way of lifting so the earring-back format is a huge win for tracking without losing data."
"It's exciting to see a wearable designed not just for women's bodies, but for women's lives. As someone who works out a lot, a ring gets in the way of lifting so the earring-back format is a huge win for tracking without losing data."
Hannah
Pilot study participant
"As a woman in STEM, I was excited to be part of a study focused on women's hormonal health, something understudied until recently. The device was comfortable, didn't impact my style, and I had no issues sleeping in it. It is a true wear-it-and-forget-it experience."
"As a woman in STEM, I was excited to be part of a study focused on women's hormonal health, something understudied until recently. The device was comfortable, didn't impact my style, and I had no issues sleeping in it. It is a true wear-it-and-forget-it experience."
Sanjana
Pilot study participant
"It was so comfortable to sleep in, I didn't even feel it, and far easier to integrate into daily life than something visible like a watch or ring. Better data and tools like this help women understand their bodies instead of guessing what's normal."
"It was so comfortable to sleep in, I didn't even feel it, and far easier to integrate into daily life than something visible like a watch or ring. Better data and tools like this help women understand their bodies instead of guessing what's normal."
FAQs
Does Phira work with any earring?
How does it track hormones without a blood test?
How accurate is the sensor?
What does Phira actually tell me each day?
What stage is the research at?
Can I join the study?
When does it ship?
Get in tune with your body.
Join the waitlist for early access and the chance to be part of the research behind Phira
Get in tune with your body.
Join the waitlist for early access and the chance to be part of the research behind Phira
Get in tune with your body.
Join the waitlist for early access and the chance to be part of the research behind Phira.