To put it bluntly, big pharma cannot patent things like testosterone, estrogen, etc., since it is made naturally in the body. There is no money in it. They CAN patent designer steroids - ones designed to hit very specific things without any side effects (such as muscle wasting in cancer patients). There is HUGE money in designer steroids...and the name they have come up with is SARM - Selective Androgen Receptor Modulator. RAD-140, for example, is in human stage 3 trials. Once complete, it will be patented for 7 years and then generics are allowed. So far it is 100% side free up to 30 times the dosage needed to be effective. It will never be over the counter, though, since a prescription will always be required. Penicillin is perfectly safe, but you cannot buy it over the counter either.
There is huge money to be make in this for Big Pharma, so expect SARMS to start exploding soon.