A prenup is insufficient unless you're also in a legal environment where a spouse can not financially make both of you jointly and severally liable for a debt, for example.

It doesn't help you if the other party doesn't get any of your stuff in a divorce if you're still saddled with debts they took on while you were married.

There may be places where this is possible, but I doubt it'd be worth it once you factor in the cost of sufficiently safeguarding yourself, unless there are massive amounts of money involved.