No non-USA shipments. It would have to go through customs and could be rejected. Also shipment is more expensive.
Their is no problem with customs (It is only a supplement) I have motorcycle parts sent to me all the time USPS and the shipping is not as much as you would think. And anyone outside the USA would obviously pay more shipping.
The other thing is that it was PWAIN that sorted out the original group buy, and I think a big effort should be made for him to be included in your offer even If you don't want to send to others outside the USA. At the end of the day its just writing an address on a box, just the same as sending it to anyone else in the USA. All you have to do is put the name of the supplement on the shipping form.
It doesn't matter to me, If I got involved I can have it sent to a friend over there in the US and then have it shipped on to me. But I really think you should make an effort for PWAIN.
Yes, someone should step up and offer to handle the group buy with international shipment included.