I believe similar legislation has passed the House before but died in the Senate. If the Senate does take it up (unlikely as it's getting late in the year for these types of bills) it will sail through without opposition. Think about it, the pharmaceutical companies want this kind of legislation and the people opposing it are Aaron Singerman and PJ Braun, which means nobody. It's not exactly a fair fight.
If the supps companies are against it, it might not move. According to "Bigger, Stronger, Faster", the "supplement industry" is largely based out of Nevada, the home state of the Senate majority leader who schedules bills for debate. No debate, no vote. Poof.