Looking for follistatin? Your chance of a bad buy is fifty percent...
Roughly half of all follistatin preparations on the black market are fake. They do not contain anything, or other muscle-building substances. Doping hunters from German Sport University Cologne come to this sobering conclusion in Drug Testing & Analysis.
Myostatin, a protein biosynthesized by muscles, is a powerful inhibitor of muscle growth. Pharmaceutical companies are looking for ways to safely neutralize myostatin, hoping to find a drug that will keep the rapidly aging population of this planet physically strong for longer. Pharmacological athletes follow this research with a great deal of interest.
Follistatin may be such a safe myostatin inhibitor. Just like myostatin, follistatin is produced by the body itself. Follistatin deactivates myostatin, and causes a substantial increase in muscle mass in animal studies. You can read more about this here and here.
In human blood you will mainly find a form of follistatin that scientists call FS344 or FS315. FS344 and FS315 are two names for the same molecule.
In organ tissues you will find FS288 or FS137.
The figure below shows how the different forms of follistatin relate to each other. These isoforms are all separate strings of amino acids, which are cut by enzymes from the same follistatin parent molecule. Cells make this parent molecule when the follistatin gene becomes active.
Although follistatin preparations have not yet been approved for human use, you can already buy research chemicals with follistaine in web stores. They are officially for "non-human consumption" and for "research purposes only", but the customers of the web shops in question know better.
The researchers bought 17 of these products and analyzed them. They don't want to tell which products they bought "in order to not provide cheating athletes brand-specific information".
WADA paid for the study.
The labels of research chems with follistatin usually mention 'FS344'. Occasionally the labels mention 'FS315', but the researchers paid little attention to those products. They were able to get one with great difficulty, analyzed the thing, but found no trace of foillistatin. It was a fake.
Of the 17 FS344 vials that the researchers bought, 9 contained follistatin (BM01-BM09). Click on the figure below for a larger version.
By comparing the 9 research chemicals with follistatin with FS344 products from recognized pharmaceutical suppliers, the researchers were able to find out that all FS344 research chems contained follistatin that was produced by a modified Escherichia coli bacterium.
All follistatin in the black market preparations also contain the same N-terminal His tag. This is a string of half a dozen histamine units that you attach to the end of a peptide. This makes it harder for enzymes in the body to break down the peptide.
The His-tag technique was developed by Roche in the beginning of this century, but in the near past researchers have often found His-tags in research chemicals. [Growth Horm IGF Res. 2010;20(5):386-90.] [Drug Test Anal. 2014;6(11-12):1117-24.]
All preparations also contain follistatin molecules that were stuck together. They were usually oligomers of 2 or 3 molecules, but the researchers also found oligomers of 4, 5 and 6 follistatin units.
The researchers bought their follistatin preparations from web stores from 9 different countries. It is not impossible that the pharmacological raw materials of those preparations come from one and the same source.
Follistatin is on the doping list, so the researchers also examined whether it is possible to make a doping test for FS344. And although the half-life of FS344 is only a few hours, they believe that the development of such a test will not cause any problems.
Drug Test Anal. 2019 Nov 23;10.1002/dta.2741. doi: 10.1002/dta.2741. [Epub ahead of print].
No IGF-1 in fake Igtropin 02.02.2019
Under-dosed Genotropin and Omnitrope in web shops 01.02.2019
Grey market epitalon products are genuine 20.01.2017
LGD-4033 in web shops is authentic - TB-500 is not 01.10.2014