I broke my 4th metacarpal bone in my right hand. how long till i can start lifting weights again?

It depends: It depends in part on the nature of the fracture, and also your ability to modify your weight training regiment to protect your hand. Most metacarpal fractures take approximately 8 weeks to heal. But again, there may be many aspects of your workout you can do, but in a different way. Thank you.

Until it heals: The answer is not meant to be funny, but it is true. Typically the bone heals in 4 - 6 weeks, but it also depends on the type of fracture and how stable it is. I would check with your physician before starting any lifting program. Going back too soon can cause the bone to break again.