...This seems to have had most people stumped.
FYI, Crampex is made by Seton Healthcare Group plc, Tubiton House, Oldham, OL1 3HS, England. There is also a phone number on the packet, from the US it would be +44 161 652 2222.
There are cautions on the pack for those with heart, circulation, kidney problems or high blood pressure.
I also find it helps to sleep with a heat source by my feet, a hot water bottle or a lavender pillow.
Zan