Hormone & sweat wearables

Domain deep-dive

Hormone & sweat wearables — biochemistry without the blood draw

Hormone and metabolic tracking used to mean episodic, invasive tests: blood draws, urine strips, or basal temperatures taken the instant you woke. A new wave of wearables is chasing continuous, non-invasive readings, and they do it in two very different ways. See reproductive-domain devices →

Two ways to read a hormone you can't see

1 · Multi-modal physiological inference

Optical sensors can't directly detect large molecules like estradiol. But hormones drive huge downstream effects — progesterone raises body temperature and reshapes sleep; estrogen shifts heart-rate variability. Devices like Clair fuse dozens of body signals through machine-learning models trained on lab hormone values to infer hormone levels, promising to resolve far more cycle sub-phases than the classic four.

2 · Direct fluid analysis

Sweat and saliva carry ions, metabolites and hormones that mirror systemic health. Electrochemical patches (EnLiSense) read cortisol and inflammatory markers continuously in situ; saliva devices (Eli Health) report hormone levels at close to lab accuracy, with no blood draw.

Inference vs direct, and why the wrist isn't ideal

Wrist devices like Ava capture several signals, but the wrist is a distal site exposed to a lot of environmental noise. The Tempdrop armband instead reads near the axillary artery, where skin temperature tracks core closely, which makes it more robust to interrupted sleep, mouth breathing and shift work. Inference-based hormone tracking is the most ambitious approach here and also the least proven: Clair's clinical trials haven't reported yet, so for now its readings are promises rather than results.

Hormone & sweat devices in WearScore

Sorted by clinical value. Several are pre-launch or research-stage — flagged on each card and profile.

Salivary hormone trackingOther

Patient education, not medical advice. Several devices here are pre-launch (Clair, Grace), research/B2B (EnLiSense), or episodic rather than continuous (Eli Health, Tempdrop). Hormone and fertility decisions should involve a clinician — verify status and validation with the manufacturer.

Domain deep-dive