Is Collagen good for bone health?

The evidence points that way, though it's not yet conclusive. Multiple independent meta-analyses of randomized trials find oral hydrolyzed collagen supplementation improves skin hydration and elasticity and reduces signs of skin aging, a reasonably consistent finding across several independent research groups. That's reflected in an evidence score of 50/100 for its role in bone health, drawn from 10 studies (2 RCTs), with an estimated impact on longevity rated limited (32/100).