T Nation

Myostatin Inhibitors' Side Effects?


Do you think that myostatin inhibitors like follistatin, myostatinâ??s propeptide, ACE-031 (Myostatinâ??s soluble receptor) or MYO-029 (Monoclonal antibody) could have a negative effect on human health? According to you, what are the possible side effects of these products? Do you think that current knowledge could allow a sufficient evaluation of side effects on short and long term?


Well, do you have access to gene expression, protein expression and sequencing/structural homology databases? Or are you just wondering?

Because the question you just asked is going to take a LOT of research.

This is why they've spent 10+ years trying to start clinical trials to figure that sort of thing out. It's unknowable. Clinicals were expected to start in 2010, but I'm not sure of the status of any of them.


I remember somewhere that in a study with myostatin inhibitors they realized that myostatin is not only related to muscle growth its also related to many important cell functions so I don't think myostatin inhibitor will ever be a route for increased muscle growth.


What about the people with a myostatin deficiency? How many top pros do you think has this? I wonder if its pretty much required to have some sort of myostatin deficiency to reach the top of the top? Thoughts?


Depends what you mean.

The myostatin-deficiency allele is pretty rare. It seems that there is a somewhat recognizable phenotype in heterozygotes (i.e. if you have one copy of the gene that's defective and one that's working, you will express moderately lower levels of myostatin than the average person, but not enough to set you apart as a "freak"). I have no idea how many heterozygous athletes there are, since most hets probably go on with their life never knowing.

That said, I would still imagine it's quite rare among pros because the allele frequency is just so low. There's only a few present cases (i.e. homozygous deficient, the real freaks which can be spotted from an early age) identified right now. While that means that the population of heterozygotes is much larger, it's still going to be quite a small number. I doubt there are any people from this camp in the pros. It's a very rare condition.


Of what i know the principal problems are rupture of tendons and bleeding nose but i think that there is more side effects than that because of action mecanism of myostatin's inhibitors... i'm maybe wrong but people who use these products don't talk about side effects.


The problem is that the inhibitors themselves are involved in an awful lot of signalling pathways and don't interact just with myostatin. It's not like anti-estrogens predominantly targeting only 5-alpha reductase.

Additionally there's the problem of dosing and of quality of compounding with these. They are novel, largely unstudied in humans in vivo, have not undergone clinical trials yet (although as I said I believe there are some underway, or just beginning but as far as I am aware that data is closely guarded and proprietary to the companys--it has not been made public to anybody).


My point is that essentially you asked a question so broad and unknowable as to be largely meaningless--because nobody has the data yet, really not much even approaching reliable data in humans let alone bioavailability or compounding issues or delivery methods in vivo. We're a long way away from knowing these things right now.


According to personal research, myostatin inhibitors can cause problems on tendons. they become more fragile and brittle on mouse. moreover some studies has to be stopped because of unexpected bleeding nose and bleeding gums... It's seems to be very hazardous to use these inhibitors!