How can I help my boyfriend to stop snoring?...

...My 31 year old boyfriend snores like a pig and it is not doing our relationship any favours!

He had his nose broken a few years back which may not help but his snoring is getting louder and louder. Does anyone have any ideas on what kind of treatments we can get from a chemist or any advice on how to quieten him down?!

Any ideas would be much appreciated.
He starts sleeping on his side and sometimes rolls onto his back. I roll him over but, generally, he will snore regardless of the position he sleeps in!

"does he sleep straight, facing the ceiling? its one of the causes of snoring. And his mouth must be open during sleep, right? Ask him to sleep turning on right or left side. Left is actually ideal, but he can choose."
(chosen answer)