Age restriction on buying lube? (Boots, Tesco)

So I'm 15 and I've been using lube for... Personal touching (im male btw) for quite some time, using my older brothers because he didnt know. Now he's moved out and gone over working in the UK, i've found myself lube-less! Vaseline is sh*t so I need some proper stuff.

So I'm tempted to going to a Boots or Tesco and buy some (own-brand or Durex maybe). One thing I'm worried about is if it's age restricted? Like I'll be trying to go through a self-service checkout (I know a few Boots have self-service, and so does most Tesco's) and will it go up and say approval needed? Or can I just carry on and it'll be fine without needing staff approval?