No it isnt, it was for quite a while after it first came out, but now you can get it over the counter (not cheap).
Regarding vaseline, a tip I was given years ago by a guy who did the LDWA 100 milers was to use pure Lanolin instead. I have used it ever since. It is really thick and gooey (Spelling?) and there is a nack to using it. It is spread thickly over the parts of the foot that need protecting (on my non stoppers - the whole foot) and the sock turned inside out is positioned at the toes and peeled onto the foot. Then smooth out getting rid off any lumps. The sock then will not move and you shouldnt have any blister problems. The socks are of course a mess when you remove them, but I have worn the same socks for over two days without removing.www.mitchellswoolfatsoap.co.uk
You will have to E mail them or phone, as Lanolin is not on their usual list, but just explain that you want a tub and they will supply.