Anyone know if you can buy 500mg potassium pills anywhere? Am fed up of taking 4 or 5 of the 99mg ones a day... Are they available over the counter? And anyone seen them in London?

Slow-K tablets 600mg (Alliance) at Superdrug...

I had to speak with the pharmacists to get it... they are NOT on the shelves.

From the label:
"Each tablet has 600mg of potassium chloride Ph. Eur. equiv. to 315mg K or approx. 8mEq of K+, in a special slow release core"

I think I paid under £5 for 100 tablets. Seems like a good value to me vs. alternatives I saw at GNC and other locations.

do you have to have a prescription, or will they just give it to you no problems...

I got conflicting info about the subject of prescription. GNC and H&B have over-the-counter potassium supplements (99mg variety), but way too overpriced, imo.

I asked a Boost pharmacist about potassium who told me (I think wrongly) that a prescription WAS necessary to purchase potassium. On the other hand, the superdrug pharmacist mentioned the issue of prescription, and consulted a book... but ultimately I was able to obtain the mentioned supplement.

I do not have a prescription, and had never heard one would be needed for purchasing potassium, a common mineral present in numerous foods.... (if a prescription was necessary to purchase potassium supplements, maybe they should require a prescription to anyone wishing to buy a BANANA, for example, since they are rich in potassium)