Hi Claire: Generally speaking, you can get just about any medications outside the US for substantially lower prices. In fact, there are lots of folks in S. border states who go to Mexican pharmacies to get their medications. However, if you need something specific and perhaps cutting edge, the answer might be different. As far as large doses, we’ve always been able to obtain very large batches of whatever was required once the prescribing doctor understood the situation–i.e., that we’d be out of touch for long periods. Hope this helps–Steve