Every day, thousands of women going through IVF treatment have blood drawn to monitor their hormone levels. It happens every two to three days, throughout the entire cycle — not because the science demands it to be invasive, but simply because no better tool has existed. Level Zero Health is changing that.
The London-based startup has developed a wearable biosensor patch that reads hormone levels directly from interstitial fluid — the fluid surrounding cells just beneath the skin — delivering results with 98% accuracy across the full clinical range. No blood draw. No urine test. No 12-hour delay waiting for results. Just a patch worn on the upper arm, measuring in the background.
The Technology Behind It
What makes Level Zero Health's approach distinctive is its use of proprietary DNA-based biosensors — a departure from the electrochemical sensing methods most competitors rely on. These biosensors are engineered to detect trace concentrations of hormones — progesterone, estrogen, cortisol, and testosterone — at the sensitivity levels required for clinical decision-making. The company achieved 98% accuracy across the human clinical range within their first year of development, a milestone that typically takes far longer in medical device R&D.
The technology draws a deliberate parallel to continuous glucose monitors (CGMs), which transformed diabetes care by making blood sugar data continuous, accessible, and actionable. Hormones have remained a generation behind — until now.
From Clinic to Consumer
The company's go-to-market strategy is deliberately clinical first. Their near-term device — a single-use intermittent patch — targets IVF monitoring and testosterone replacement therapy (TRT), two use cases where frequent hormone data directly influences treatment decisions. They have already secured $3 million in letters of intent from major IVF clinics, signalling strong institutional demand ahead of launch.
A continuous monitoring version is in development for 2028 — the longer-term vision being a device that tracks hormonal patterns across the full cycle, with implications for fertility, perimenopause, athletic performance, and beyond.
In February 2025, Level Zero Health closed a $6.9 million pre-seed round — the largest pre-seed ever raised by a female-founded company in Europe — led by Swiss VC Redalpine, with participation from HAX (SOSV) and Entrepreneur First.
About Level Zero Health
Level Zero Health is a London-based femtech medical device startup developing non-invasive hormone monitoring technology. Founded in 2023 by Ula Rustamova (CEO) and Irene Jia (CTO), the company is pursuing FDA clearance and CE marking for its first clinical device.
