Smoothie King - safe?

I ordered a smoothie from Smoothie King and afterwards was paranoid that it might not be safe.

It had a diet down enhancer in it (which I googled and it had a note to consult with your healthcare provider before drinking). I used to drink this smoothie all the time and stupidly didn’t notice or check the ingredients thoroughly before ordering it.

Has anyone accidentally or intentionally had something with an enhancer and/or know if it’s safe?