Women: Stay informed with the
Menopause Type® E-News. Subscribe Now!

Home  |  Symptoms & Risks  |  Ask Dr. Collins   |  Q & A Library  |   Find a Physician  |   Choose a Pharmacist  |  Site Map

Speaking Schedule  |  The Book  |  About the Author  |  Herbs  |  Nutritional Supplements   |  Your Hormones  |   Seminar  Questionnaire | Lab Tests |  Hormone Choices | Resources for Women | Pharmacists Resources | Physicians Resources


Calculating the P:E Ratio & Quartile Analysis

Question: I have a question concerning calculating P:E ratio. After reading the directions in the book, I'm not sure how to do this.

My saliva test results were:


Estradiol 1.2 pg/ml


Progesterone 0.07 ng/ml


Testosterone 15.9 pg/ml

Any comments concerning these results would be appreciated.

I am 46 years old, had a total hysterectomy 4 years ago and am using a transdermal estradiol patch.

Based on the Menopause Type® Questionnaire, I am Menopause Type® Eight


Quick Answer:

A little bit of mathematics and you will see that you also have a Menopause Type® Eight picture based on lab tests.


P:E Analysis

Most of the confusion about P:E Ratio analysis is due to not reporting in the same unit or measurement.

Common mistakes include comparing nanograms to picograms, especially since there are 1,000 picograms per 1 nanogram.

Another common mistake is failing to convert to MOLES as the unit of measurement. Since the P:E Ratio is measuring the ratio of progesterone and estradiol molecules, they must be calculated in moles (see Why P:E Ratio must be measured in Moles below). The pMol/L is also the International Unit of Measurement for these hormones.


Nanogram & Picograms

First, note that estradiol is reported in pg/ml (picograms per milliliter) while progesterone is reported in ng/ml (nanograms per milliliter). In order to compare the ratio of these two hormones we need to do some math to get them both into the same “weight units”.

Since there are 1,000 picograms in each nanogram, one nanogram of progesterone is actually 1,000 picograms of progesterone.

So, let's convert progesterone to picograms: 0.07 x 1,000 = 70 picograms

We now have:

Progesterone 70 pg/ml

Which we can compare to the Estradiol 1.2 pg/ml - - - AFTER we convert to MOLES


Convert to MOLES

Since we are concerned about the correct number of progesterone molecules for each estradiol molecule we fist want to convert the lab results into pMol/L.


This conversion is really quite simple once we have the conversion factors:

Estradiol Conversion Factor: pg/ml x 3.671 = pMol/L

Progesterone Conversion Factor: pg/ml x 3.18 = pMol/L


Doing the math we get:


Estradiol 1.2 pg/ml x 3.671 = 4.41 pMol/L


Progesterone 70 pg/ml x 3.18 = 222.6 pMol/L


Calculate the Ratio

To calculate P:E ratio divide progesterone by estradiol. Doing the math we get:

222.6 / 4.41 = 50.48 (rounded to 50)

So the P:E ratio is 50:1, which means there are 50 progesterone molecules to every 1 estradiol molecule.


The P:E range is from 20: 1 to 170:1.



P:E Quartiles

Recall that symptoms will help determine how to interpret lab results (review pg. 27 - 29). Applying what we know about quartiles (pages 49 - 50) to the P:E ratio we recognize four P:E quartiles as:



First Quartile:

20:1 to 57:1



Second Quartile:

58:1 to 95:1


Third Quartile:

96:1 to 132:1


Fourth Quartile:

133:1 to 170:1


Reported P:E is in the First Quartile. A P:E Ratio in the First Quartile may be experienced as “feeling low progesterone”, especially if the woman was used to having a higher P:E ratio when she was younger.


Testosterone Quartile Analysis

Concerning the testosterone levels:

Reported Testosterone = 15.9 pg/ml


This would be converted to pMol/L as follows

Testosterone Conversion Factor: pg/ml x 3.47 = pMol/L

15.9 x 3.47 = 55.1 pMol/L


With an Ideal Testosterone Range of 64 to 164 pMol/L, the reported levels are below ideal range.


Putting it all Together

So we have three points to consider:


Symptoms (Questionnaire) suggest Menopause Type® 8 (low progesterone, low testosterone)


P:E ratio is in the lowest quartile


Testosterone level is below ideal range


Low testosterone levels and a relatively low P:E ratio (first quartile) explain why Menopause Type® 8 symptoms are presented.


If P:E ratio is in the first quartile and a woman still has symptoms of low P:E ratio (as demonstrated on questionnaire), she should discuss this with her physician who may advise her to raise her P:E ratio by taking a small dose of bioidentical progesterone.


It is not uncommon for women who have had hysterectomies to be prescribed estradiol without progesterone. This is based on outdated ideas in which progesterone was only recognized as having value in protecting the uterine lining. Thus, women without a uterus were considered to not need progesterone.

When a woman says to me “My doctor says I do not need progesterone because I do not have a uterus.” I say, “Ask your doctor if you still have bones, skin, brain, eyes, et cetera. Every tissue we know of has progesterone receptors.” Consider sharing the Actions of Progesterone document.

Testosterone enhancing therapies should also be considered. These may include nutritional, herbal, or glandular therapies. Hormone precursors or natural hormones may also be considered.

It is important to follow up any therapies with re-testing of the hormones at three months, to evaluate whether hormone balance has been achieved.



When done properly, saliva hormone assessment and the analysis of ratios and patterns can provide valuable insights into the unique needs of each woman.

When done improperly - mixing nanograms with picograms and calculation ratio with conversion to Moles – confusion and doubt arise.


For references and more information of P:E Ratio analysis, please review 77 – 80 of Discover Your Menopause Type®.


Why P:E Ratio must be measured in Moles

Mole - A mole is a gram molecular weight, that is, the molecular weight expressed in grams. The molecular weight is the weight of one molecule in daltons. All moles contain the same number of molecules, Avogadro's number, equal to 6.022 x 10@ The reason all moles have the same number of molecules is because the value of the mole is proportional to the molecular weight.

One Mole of progesterone is 314.4668 grams of progesterone.

One Mole of estradiol is 272.3864 grams of progesterone.

There are the same numbers of progesterone molecules in 314.4668 grams of progesterone as there are in 272.3864 grams of progesterone – one molecule of progesterone to one molecule of estradiol.

To calculate P:E ratio based on grams, or nanograms, would give an erroneous result. Mathematically, 314.4668 divided by 272.3864 = 1.15 – creating a 15% error.

When P:E ratio analysis was first introduced by Dr. Collins in the mid-90s, it was based on an extensive review of medical and clinical chemistry literature (much of the published work used PMol {picoMoles} in their research. Recall that the pMol/L is also the International Unit of Measurement for these hormones. It appears that when other labs adopted the P:E ratio, they overlooked the need to convert to Moles.



Last Updated 042504

YourMenopauseType.com, Inc.
Copyright © & ® | Disclaimer and Legal | Contact Us