Three-and-half years of shift work (interesting, well-paid work for a good employer and decent working conditions) did me physical harm that did not wear off for many years after the experience. I felt listless, short on energy and intitative and thinking power, slightly better while on days, but very bad while on nights. That listlessness was still with me for years afterwards.
During those years, I experienced three different shift patterns. Rotating once a week (day, evening, night) was worst - pretty hellish. Rotating once a month was bearable. I once did 4 months straight on nights - to my surprise, that worked OK (physically). At the end, I was back on weekly rotation and couldn't wait to get out.
Shift work wrecks your social life. Your friends never know where you're at, so they don't include you in their plans, and you don't have the energy yourself to organize anything.