That's a big odd - because creatine seems to be the universally beloved thing and that it's a bit natural and has positive effects with zero negative side effect. Not a criticism but aside fro proten, creatine seems to be 'the natural thing'. Pun intended.
There's two sides to this.
1. That's because it's true. Creatine is extremely well studied and the studies pretty much all tell you that Creatine is safe, it's great at what we know it's great for, and it turns out it might be good for things we didn't expect. So when people all say "wow it's so amazing" they're right.
2. Because of (1) being so blatantly true, if you want to push some other supplement, it adds a lot of legitimacy to say "Creatine is the number one supplement, but here's something that takes things to the next level". Since the Creatine claim is well supported and you're already marketing to a group that's taking a supplement (Creatine), it is likely good marketing to piggyback on that.
But this doesn't change the fact that Creatine is shockingly well supported as a supplement.
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