Goldspink hopes MGF will be used therapeutically within five years. Athletes are already experimenting with IGF-1, which is widely sold on the Internet (mostly by companies that seem less than concerned about its safety). So far, MGF hasn't found its way to the gym black market because Goldspink has tightly limited its distribution and because MGF is tricky to make, but it's just a matter of time before MGF slips out to athletes.
If MGF doesn't work or isn't safe,
2) Running Forever
The other goal for muscular enhancement is increasing endurance. Endurance depends on oxygen uptake and delivery. If you don't get enough oxygen to muscles, lactic acid production spikes, and you weaken and tire. Great long-distance athletes like Lance Armstrong are able to keep collecting oxygen and feeding it to muscle cells long after you and I would fade. Oxygen is carried by hemoglobin, the chief component of red blood cells. So, generally, more red blood cells means better wind. (Endurance, incidentally, is not the same as speed. Speed depends on muscle strength, which is why sprinters so frequently abuse steroids.)
In the early '60s, endurance athletes took blood transfusions from others to increase their red blood cell count. This wasn't very safe—transfused blood can carry disease or provoke immune reaction—so a few years later they started banking their own blood months before competition. This way, the body would have time to regenerate the lost red cells, and then, at competition time, the athlete would take the transfusion of his own blood, giving himself an extra measure of hemoglobin-rich blood.
Eventually, scientists and trainers cottoned on to EPO, a natural compound whose function is stimulating the bone marrow to produce more red blood cells. Amgen began producing synthetic EPO, and many endurance athletes started injecting it several times a week. (The most recent long-acting variation, darbepoetin, is even more effective and can be injected every couple of weeks.)
But artificial EPO is dangerous: Too much EPO supercharges red cell production, which, as noted above, can thicken the blood and cause heart attacks. Frequent needle injections are inconvenient and unpleasant. And tests can detect synthetic EPO—a problem for competitive athletes.
There are two potential strategies for those who desire convenient, safe, and undetectable methods for boosting oxygen capacity and extending endurance.
The EPO Gene
The first is to engineer a gene for EPO that enables the body to increase its own EPO supply. Dr. Gary Wadler of NYU Medical School, author of Drugs and the Athlete and the White House adviser on doping, described how this will be done in a recent article, "Future and Designer Drugs: Emerging Science and Technologies." The EPO gene can be attached to a small bit of DNA called a plasmid, which would be injected into the muscle. Many muscle cells would absorb the new gene and start pumping out extra EPO. To prevent the EPO from running wild—from stimulating so many red cells that the blood thickened—the gene would have an on-off switch that would be activated only when the patient took a particular drug. This EPO gene therapy, Wadler told me, "is likely to be first to market" of the new sports enhancement technologies.
Both the gene therapy and the on-off switch are new. There's no long-term data about how safe and effective they are.
Now, or very soon.