Please bare with me guys this is going to be a long and involved post but hopefully interesting nonetheless.
First my current protocol:
So I decided to check IGF-1 levels given the protocol above and that I had previously tested this GH at 3.75iu per day and returned an excellent result of 458 ng/ml. Anyone who does blood testing in the UK will know that IGF-1 testing is very expensive and quite difficult. There was effectively only one lab that could test it and the lab I used would outsource the testing to this service. They however decided to invest in their own iummunoassay based analyser and so when I went to test this time they used their new analyser at a significantly reduced cost. Sounds good so far!
However when the tests came back - look at the first picture - you will see that IGF-1 cam back pretty low at 271.1 ng/ml. On the surface this would seem very disappointing and it was. It was also pretty weird as I knew I was on quality GH as I had all the typical side effects as well pretty compelling results. Also worthwhile noting that my baseline IGF-1 is 297 ng/ml. A few other stand outs from this batch of tests:
So given all this and in agreement with the lab we decided to test IGF-1 again a week later (Wednesday this week) as well as estrodial and for Heterophile antibodies which in my research were known to cause interference with both IGF-1 (false lows) and estrodial (false highs) with immunoassay based tests. The IGF-1 tests would be done on the new analyser as well as sent off the the lab service historically used. I also switched from the Krotos exemestane to the Pfizer exemestane. I kept Ironlion updated throughout this process and he encouraged me to proceed and to post the results regardless of the outcome.
Results are in pics 2 and 3. Here is the summary:
So the question remains as to what is causing the interference with the new analyser my lab was using but not for the historically used one. The truth is I don't know the answer but I do have some suspicions. You may have seen some other recent and relatively disappointing IGF-1 results for another well known and respected lab which I can't mention here due to cross posting rules.
A common theme is that we were both running Proviron (I was also running anadrol). Proviron and other DHT's have been know to reduce IGF-1 number on blood tests. We had always believed it was therefore not necessarily the best idea to run DHT's and GH a the same time due to the IGF-1 lowering effect of DHT's. I am now questioning this assumption as In believe the logic is flawed.
A more likely and logical conclusion is the DHT's are in fact causing some sort of interference with the immunoassay based IGF-1 tests generally used. This has never been researched which is not surprising as DHT drugs are hardly ever used in clinical settings.
The way around this is to always do IGF-1 Tests with a lab that does LC/MS testing and that way remove the possibility for immunoassay based interferences. This type of testing is now commercially available in the US where most of you guys are based - https://www.questdiagnostics.com/testcenter/TestDetail.action?ntc=16293 and I understand that LabsMD uses quest. Labcorp only uses immunoassay based test so keep that in mind. In the UK it is more complicated as LC/MS does not seem to be commercially available although from my research it is used in some of the major NHS research and teaching hospitals. Details on the methodology used by the historic lab service where my IGF-1 tests have always been outsourced to are not publically available and I have a question out there with my lab as to what methodology is being used. Given the size of this service (one of the largest in Europe and the largest in the UK) it may be that they are testing with LC/MS. If I get an answer to this I will update here.
I'll end my stating that Puretropin GH remains an excellent product in my view
UPDATE: The first test was run of the Maglumi/ECLIA Immunoassay and the second tests were run of this and the Diasoran XL/CLIA Immunoassay which I had been using up until now for all my IGF-1 tests