Why Men need to request the sensitive, LC/MS assay for serum E2 measurement

Why Men need to request the sensitive, LC/MS assay for serum E2 measurement

Why Men need to request the sensitive, LC/MS assay for serum E2 measurement

A real World Example of why Men on TRT or using AAS might need to request the sensitive, LC/MS assay for serum E2 measurement

LC/MS assay offer greater sensitivity and lesser interference by other steroids.

The commonly used estradiol test may overestimate estradiol.

That test uses immunoassay technology that might be cross reactive to other compounds and cannot differentiate C-Reactive Protein (involved in inflammation) from estradiol, so it reads the combination of the two as estradiol.

This sensitive estradiol test is based on liquid chromatography/mass spectrometry (LC/MS), an assay technology that does not have that limitation.

Look at the difference here on this client from the same Blood Draw, the Lab he used did not do LC/MS assay in-house and so hence different Labs here.. but same client, same single blood draw, same day


AAS use at the time of this Blood Draw

500mg Test Enthate Week
500mg Nandrolone Week
12.5mg Aromasin EOD

Victor Black

J Clin Endocrinol Metab (2013) 98 (6): E1097-E1102.

Immunoassay-based techniques, routinely used to measure serum estradiol (E2), are known to have reduced specificity, especially at lower concentrations, when compared with the gold standard technique of mass spectrometry (MS). Different measurement techniques may be responsible for the conflicting results of associations between serum E2 and clinical phenotypes in men.


Our objective was to compare immunoassay and MS measurements of E2 levels in men and evaluate associations with clinical phenotypes.

Design and Setting:

Middle-aged and older male subjects participating in the population-based Osteoporotic Fractures in Men (MrOS) Sweden study (n = 2599), MrOS US (n = 688), and the European Male Aging Study (n = 2908) were included.

Main Outcome Measures:

Immunoassay and MS measurements of serum E2 were compared and related to bone mineral density (BMD; measured by dual energy x-ray absorptiometry) and ankle-brachial index.


Within each cohort, serum E2 levels obtained by immunoassay and MS correlated moderately (Spearman rank correlation coefficient rS 0.53–0.76). Serum C-reactive protein (CRP) levels associated significantly (albeit to a low extent, rS = 0.29) with immunoassay E2 but not with MS E2 levels. Similar associations of immunoassay E2 and MS E2 were seen with lumbar spine and total hip BMD, independent of serum CRP. However, immunoassay E2, but not MS E2, associated inversely with ankle-brachial index, and this correlation was lost after adjustment for CRP.


Our findings suggest interference in the immunoassay E2 analyses, possibly by CRP or a CRP-associated factor. Although associations with BMD remain unaffected, this might imply for a reevaluation of previous association studies between immunoassay E2 levels and inflammation-related outcomes.

from J Clin Endocrinol Metab (2013) 98 (6): E1097-E1102.

Comparisons of Immunoassay and Mass


Are the use of Ai’s “controversial” ?

Are the use of Ai’s “controversial” ?

I would have to disagree with its ” controversial”

Yes in our tribe ok

But do a search on Medical literature

Anastrozole and bone > 16,000 articles
Anastrozole and cognition > 4000 articles
Anastrozole and vascular > 10,500 articles
Anastrozole & sexual function >10,000 articles

You could probably never read all there is to read on this subject

Bad for your bones
Bad for your Brain
Bad for your Heart
Bad for the Bedroom

We all should be doing everything in our power to not live on them

Short term use ? that’s unlikely to be a major issue

Gyno “Treatment” sure – who has not done that, it’s part of clinical practice here even for ” non drug induced gyno”

But we dont want to “live” on them – not for 20 years

hell we have enough stress on these systems without taking drugs that just make everything worse.. that you dont ” need” to take

Victor Black

IGF-I with Nandrolone or Stanozolol elevates E2

Now this is interesting

Looks like Aromatase expression is induced by the combined treatment of IGF-I with nandrolone or stanozolol to levels higher than those obtained with the single agents

Takeaway if you use rHGH /IGF-1 Lr3 and AAS in combination

Expect higher Estrogen Control Issues, much much higher with Nandrolone

Victor Black

Vitamin D downregulates Aromatase Expression

I am convinced that one of the reasons that I don’t need an Ai at 300mg a week of Test is because I ” set myself up” for it..

It’s not just a case of bang it in a see how you go..

” Fuck Victor not Micronutrients again ? haha

Cant you just let me eat my chicken and brocolli and rice in peace haha “

Ah yep ! Vitamin D this time

Wait you’re telling me that Vitamin D downregulates aromatase expression ?

ah well you can add that to the loooooong list of things it does sure

Vitamin D Dosage Recommendations here