Pregnanediol Glucuronide (PdG)

The urine marker of progesterone — the hormone that rises after ovulation.

PdG is what progesterone becomes by the time it reaches your urine. Because progesterone only rises meaningfully after an egg is released, PdG answers the question an LH test can’t: did ovulation actually happen? Together, the two markers turn cycle tracking from prediction into confirmation.

What PdG is

After ovulation, the empty follicle becomes the corpus luteum and begins producing progesterone — the hormone that prepares the uterine lining and sustains the second half of the cycle. The liver processes progesterone into pregnanediol glucuronide, which exits in urine, where a test strip can read it.

Why levels rise

PdG stays low before ovulation and climbs in the days after, staying elevated through the luteal phase. An LH surge says ovulation is likely coming; sustained PdG says it came — and that the cycle produced the progesterone rise that follows a genuine ovulation.

What a result can tell you

Testing PdG in the week after a positive LH test confirms the cycle was ovulatory — valuable information when trying to conceive, since cycles can show an LH surge without releasing an egg. It also gives you and your provider something concrete when investigating irregular cycles or early miscarriage concerns.

What it can’t tell you

A urine PdG strip reads a threshold, not an exact progesterone level, and it can’t diagnose luteal phase problems on its own — that interpretation belongs with your provider, often alongside blood work. Levels also vary with urine concentration, so consistent timing (first morning urine) matters.