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PROGESTERONE – Are Your Patients’ Serum Levels Dropping?

PROGESTERONE – Are Your Patients’ Serum Levels Dropping?:

Neal Rouzier, MD


Dear Neal,

Has there been any progress on new reference ranges on progesterone? My patients are coming back with levels of 2-5 ng/mL which was confusing to me until I read on the forum about the reagent. I’d appreciate any update.

Based on looking at many recent tests, I think the new range should be at least >2. Still working on that with LabCorp.  Again it is completely arbitrary and nebulous. Unfortunately the manufacturer of the new reagent, nor LabCorp Executives, have recommended a certain level of normal or optimal to shoot for. Just goes to show how these numbers are picked and how they should be used as only a guide.

The consensus meeting of OB/GYNS in Europe last year felt that a level of 10 ng/dl was adequate for endometrial protection.  Unfortunately that number was established using the old reagent but has now been discontinued.  Ultimately the number that will be decided on will be based on negotiations between me and a few pathologists at LabCorp.  Now how scientific is that?  Hard to believe that LabCorp would suddenly start using a new reagent without reference ranges and without alerting the public as to their doing so.

Use the number as a guide but keep an eye on bleeding or spotting.  Based on doing this for 20 years, I still feel that the doses we prescribe (100mg SL or 200mg PO) should be adequate for most women.  The OB/GYN community does not follow levels like I do, so a lot of their dosing is based on the studies that show 200mg PO is protective, which in our experience results in P4 levels of at least > 10ng/dl.  In my experience, about 20% will require more progesterone to prevent endometrial proliferation.  Use your clinical judgement as well as inform the patient to be alert for any abnormal bleeding/spotting which would then require an endometrial ultrasound/biopsy and dosage increase of progesterone.  So we never will truly know the exact or best level to shoot for, however with time and experience we will eventually come to know what level to shoot for in most women, with a few outliers requiring more.  Remember all women are like snowflakes, all are different and will respond differently depending on cellular sensitivity to progesterone and intestinal absorption.

We hope this preliminary information is helpful, please comment as we all work collectively to resolve this issue.  Thanks to many of you for reaching out with your initial concerns, it has helped us to better figure out what is happening as we reach out to LabCorp to re-establish some starting guidelines.  As soon as we have more definitive information Dana will send along an update.


– Neal

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Comments (8)

  • Susan Stopper Reply

    Thank you so much. Great information and update!

    February 15, 2017 at 8:36 am

    Is Quest now using the same reagent as LabCorp?

    February 15, 2017 at 9:10 am
    • Reply

      Apparently so.

      February 16, 2017 at 11:52 am
  • Karla Wakim Reply

    Hi, Neal. Hope all is well. Thanks for the insight. I also spent a significant amount of time with the head pathologist at Lab Corp. They finally sent me a “chart”/comparison of the second generation test results vs this new third-generation test results. It took several weeks to get it as they had to get it approved through their legal department. I am happy to forward it may be helpful for others (In addition to adjusting doses based on signs and symptoms such as bleeding or spotting).

    I was so frustrated with them as I placed six separate phone calls questioning them if anything in their testing changed during the fall as I was getting results that did not make sense. Each person I spoke to assured me that nothing had changed. Finally they realized there was a problem after Medquest had tested for purity and potency and I sent a spread sheet with multiple patients values whose ranges were off by 15 to 20 despite being very compliant patients. 🙁

    February 15, 2017 at 1:56 pm
    • Reply

      Hi Karla: Yes I had the same problem/issue. Everyone there failed to acknowledge any problem. I finally found someone that was interested to try to fix the problem. No one there seemed to care or give a damn. Very disappointing for such a large organization. I explained to them that I would advise thousands of physicians to never use Labcorp again and it finally got someone’s attention.
      Please send me the flow sheet that they sent you as I have not seen that yet. They promised me that they would test labs using both reagents and then send that to me. I have not heard or seen anything yet. Probably best that I just guess where they should be as opposed to relying on what they say as I’m convinced that they have no —-ing clue. My best to Pierre. Neal

      February 16, 2017 at 11:52 am
  • Becky Jenson Reply

    I am so relieved to hear this info….as I am having the same frustration at not budging levels to where Neal has recommended, increasing progesterone doses and again not achieving levels even above 10. I am glad to know my own hormones really are working and I’m not going crazy!! Thank you for the update!!! It is so appreciated

    February 15, 2017 at 11:00 pm
  • Robert Goldman Reply

    Hi Folks,
    I took the courses with Neil about a decade ago. I work in Atlanta and have spoken to Andre Valcour at LabCorp in Birmingham, AL about progesterone and female testosterone levels.
    100mg of oral progesterone used to get me levels of 3.0 to 5.0 or so. Now commonly they are 0.7 to 0.9 in the same patients on the same meds. The lab has a problem

    I was also seeing testosterones of over 100 pg/dl in fully menopausal women on no testosterone, with no partner who could expose them to Testosterone cream. I discovered that the problem was gel tubes. Since they started measuring testosterone in women using molecular weight mass spectrometer, the gel in the gel tubes gave falsely high readings. We now send a separate plain empty red top to measure the female testosterone. Although this solved the problem if the blood is drawn in my office, they have not spread this information to all the drawing stations. Quest understands this issue and insists that an empty red top is sent on all testosterone, both male and female.

    I agree that Dr. Valcour at LabCorp does not seem to be concerned about the clinical implications of the results they return. I am sure, as few doctors measure testosterone routinely in women, no one else complained about the incorrect results or the changes in the standard. Nice to know someone else is paying attention.

    Keep up the good work,
    Robert P. Goldman, MD
    Georgia Hormones, PC

    February 16, 2017 at 7:15 am
    • Reply

      It is very disconcerting that the pathologists at the largest lab in the U.S. don’t have a clue and don’t care. And the numbers are arbitrarily picked and posted. I have been dealing/arguing with them about testosterone ever since they implemented a new reagent for measuring testosterone several years ago. The test information/results that they have sent to all of us practitioners are severely flawed and they don’t seen to care. And there is nothing that we can do about it. Needless to say I just use the lab as a guide, telling the patients that the numbers are inaccurate if too high. Very unfortunate. Thus I rely more on how the patient feels and not the lab tests which can be inaccurate. Sad but true. In one of the upcoming webinars I will present all the articles showing how the labs are meaningless. So why test? Only to show the patient that the numbers have improved. Neal

      February 16, 2017 at 11:59 am

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