Are cheap metal bed frames actually sturdy enough for a heavy mattress?

For most adults and standard queen mattresses, yes — frames like the Amazon Basics and NEW JETO carry advertised capacities well above 600 lbs and have tens of thousands of positive verified reviews. However, r/Frugal and r/BuyItForLife commenters caution that very heavy sleepers or people who 'throw themselves into bed' will see faster wear on budget steel frames, and a solid wood option like Zinus Vivek or Mellow Naturalista is a better long-term bet.