I’ve observed occasional drops and fluctuations in my patients’ PdG levels. What could be the reason for this variability?Updated 3 months ago

Fluctuations in progesterone, including dips and spikes in urinary PdG, are not uncommon and can be influenced by several physiological factors, such as the timing of collection, hydration, or recent activity.
Progesterone tends to be more variable than other hormones like LH or E3G. Notably, serum progesterone itself can fluctuate dramatically—research shows it can vary up to 8-fold within a 90-minute window and range from 2.3 to 40.1 pg/mL over a 24-hour period in the same healthy individual (cite). These natural fluctuations can contribute to the variability seen in urinary PdG patterns.