It is also my understanding that the standard RIA test for progesterone has a lot of cross reactivity from other hormones. This gives the test falsely elevated results. I’ve been looking for studies to find progesterone ranges in men measured by LC/MS. This study
Reference intervals of nine steroid hormones over the life-span analyzed by LC-MS/MS: Effect of age, gender, puberty, and oral contraceptives
The study looks at 9 hormones measured with LC/MS. A total of 4678 samples roughly half male half female aged from 0-79.
Majority of the mens progesterone was measured under 1 nmol/L or 0.3 ng/mL. You have to use a site such as sci-hub to view the study,