Estrogen suppresses body temperature, while progesterone raises it. The combination of the two creates a measurable temperature shift at ovulation when the body switches from having majority estrogen to majority progesterone.
Armband Size Guide
Upper arm circumference
How to Measure
Size chart
| Size | Inches | cm |
|---|---|---|
| Standard Armband | 8.5″ – 15.5″ | 21.5 – 39 cm |
| Extra-Long Armband | 12.5″ – 18.5″ | 31.5 – 47 cm |
