What is more likely is that the US have threatened to place trade embergos on other exports coming out of China unless they work with the US to stem the tide of drugs entering the US originating from China. They have successfully done this in the past. Europe did it to Japan decades ago by making all Japanese exports entering Europe go through a single entry point causing insane back logs in orders that simply couldn't get through customs.
Its doubtful that China will do anything more than just appease this on the surface, like they do with the fake clothes industry that is rife out their. International law is complex, but it is unlikely a Chinese indivudual would be criminally prosecuted for processing orders of a hormone that is legal within their own Country, they would most likely receive trade fines for breaching trade agreements.
The Chinese will never bow down to the US completely, they only ever make small token appeasements, as they did when the US introduced anti-dumping laws to stem the tide of dirt cheap clothing and footwear coming out China. Look how long that the effects of that lasted?
America's economy relies on cheap produce coming in from China, just as much as China rely on being able to export to the US. Russia have very little clout with regards to anything as their economy is tiny. They rely on aid from the West so have to do as they are requested but China has just as much power as the US. They are one of five Countries including the US, UK and France that have the power of VETO on the UN Security Council, they have the largest economy in the world, have nuclear capabilities, and will soon exceede the US as the worlds super power. Their Army is massive by comparison to the US.