I've never used electrolyte supplements, and I've never needed to.
I've always got my electrolytes through the foods I eat while riding, such as salted french fries, potato chips, bananas, dried apricots, salted almonds, etc.
Also over the past two years, with the exception of a month in Australia, my cycling has been done in fairly cool temps, so sweating off electrolytes hasn't been a big factor. In fact, over the past couple years it has rarely been over 25C/77F degrees. It has rarely been anywhere near 25C/77F!! (global warming, indeed!!)
However, my last two long rides have been done in warmer temps, and I have come to the conclusion that my struggles on those rides are likely the result of electrolyte depletion.
I've got two more long rides coming up in potentially hot conditions, and have decided it might be a good idea to get ahold of some electrolyte supplements. But since I've never used the things, I'm not sure what to look for, or where to look for them.
I know eCaps/hammergel has something, but I have trouble getting stuff from them over the border. Are there any products which can commenly be found in a local pharmacy? If you've used these things, have you had more luck with one product than another?