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)