Sending Supplements to the USA from Canada

Can I ship cinnamon extract supplements from Canada to the USA?

I received an order from a USA customer for a bottle of cinnamon extract supplements. I packaged it up and gave it to my courier, but the package seems to be sitting and not moving. I am checking the updates with the courier and my other packages have moved, but not the 1 package that contains the supplement.

When this happens (a package not moving through the courier's tracking system) it usually indicates the courier has decided the package contents is an issue.

The thing is that the supplement was manufactured in the USA and I am sending it back into the USA. It is legal in the USA and Canada and I don't see an issue with it, but I am not an expert on this type of thing, so I could be wrong.

Anyone know if you can send supplements to the USA from Canada?

Thanks