Lower levels of myostatin activity, achieved either through genetic engineering or blockade via antibodies, cause muscle growth. In the former case, where individuals lack functional myostatin throughout their lives, the result is lot of additional muscle growth; twice as much muscle tissue, or more. In the latter case the effects are smaller, but still significant. A short course of myostatin antibody treatment in mice added 20% extra muscle mass, and in humans a six month trial in elderly people added a measurable amount of additional muscle, while improving functional measures that typically decline dramatically in later age. There are a range of animal species in which it is possible to find established heavily muscled lineages with myostatin loss of function mutations of one sort or another: dogs, cows, and mice, the mutation either naturally occurring or created in the laboratory. There are even a few humans in the naturally occurring category.
Given the large numbers of myostatin-deficient animals, the extensive data on those animals, and results from human trials and the run up to those trials, it seems that manipulating one's own myostatin activity as an enhancement is something to look into for the near future. As in why don't we set out to try this today? Extra muscle with no effort is probably a nice to have for the younger folk in the audience, but the real application here is as a compensatory therapy to meaningfully delay the onset of physical frailty in older age. It doesn't solve any of the underlying issues that cause loss of muscle mass and strength with age, but it does appear to help a great deal more than other approaches are likely to at the present time, and is additive with those approaches. Young people can always substitute time and willpower for technology on the additional muscle front, but that option fades in effectiveness in later life - the returns on investment diminish greatly as age-related degeneration accelerates.
Viable myostatin or related follistatin and smad7 gene therapies for adults are a few years away yet, I think, pending a robust solution to tissue coverage. Methodologies must be developed to reliably ensure that therapies edit the genome in enough cells to be effective, but this is a challenge for everyone in the industry. It will not go unsolved for long now that CRISPR-based gene editing is a going concern. Still, a few years from now is not today. The antibody approach on the other hand is something that could be carried out today, if you had a reliable supply, dosage information, and the necessary materials to self-administer via injections. Give this list of ingredients, all of which are out there, I'm fairly certain that a range of individuals are already quietly doing exactly this. It will be the usual suspects, a mix of professional athletes and forward-thinking folk with laboratory experience and access. So why not forward-thinking older people as well?
The immediate raw materials to hand consist of research papers, study results, and suppliers of myostatin antibodies. From the research papers and study results one can obtain the particular brand of antibodies used and the dosages and treatment duration. There are a number of suppliers, such as Abcam, or take your pick of the dozens of others. Not all of which are providing a product that is appropriately useful in this context, of course. Not all suppliers sell to just anyone in this modern world of regulations and the drug war, either. Ideally you would pick the same antibody source as was used in one or more papers, and for preference the exact one used in a human trial. Human trials, however, have a way of being associated with specific companies, and they will probably be making their own, or exclusively licensing someone else's product. Regardless, there are choices, and a choice can be made. But most importantly, one has to verify that the supplier is actually delivering something that works.
At this point it would be prudent to obtain access to a laboratory and run tests. In our community there are a number of groups with the connections to kick that off. Let us say, for the sake of argument, a group buy organized by Longecity with additional fundraising to pay for the labs used by the Major Mouse Testing Program to validate that the product works in mice. There are three or four other organizations that could substitute in for either of those. The testing could even be structured to obtain useful scientific data in older mice, perhaps, which is something that seems a little less well exercised than the use of myostatin antibodies in younger mice. Overall that should not cost more than a few tens of thousands of dollars if picking a thrifty organization, and nor should it take more than a few months once the money is in hand.
There are matters other than the purely technical to be dealt with, however. Somewhere along the way the aforementioned prudent individual will engage a lawyer or two to figure out which part of buying the antibodies and injection kits and then self-administering is illegal or otherwise risky in the present jurisdiction. This will probably cost as much as the testing, which is a sad statement on the priorities of this fallen world of ours. This is the drug war age, and anything involving needles and biotechnology that falls outside the bounds of medical practice is at the least something that will raise the odds of attention from unwanted quarters. No purchase goes unmonitored for some types of apparatus, and injection kits are no doubt on that list. Further, everything involving medicine tends these days to operate on a forbidden unless explicitly allowed model, more is the pity. So all in all there is, as ever, a large difference between what one can do with little effort and what is prudent to do on one's own, without support or forethought.
Still, it seems to me that this is a viable project to explore further. The technology appears to have a good expectation of positive results given the human and extensive animal data to date, provided that the right tools are used, and there is a lot of data to establish dosages and the right products to use. The plausible worst outcome from an investigation of the legalities is likely to be along the lines of "contract the injecting to a clinic in Mexico or Canada." The whole exercise of research and validation outlined above is well within the capability of a motivated group of people pitching in a few thousand dollars each. The parts where it might cheerfully fall apart are in the cost of the desired antibodies, or in establishing a relationship with a supplier willing to go along with a group of people who are self-administering. That will no doubt make their legal teams nervous. It might be necessary to add an intermediary clinic or laboratory to the mix regardless of the formal legal status of the activities.
But you don't know unless you try.