Can "Blood Lust" take me above max damage?

After conducting some research, I do believe the answer is no. Once you have your damage maxed, Blood Lust will not increase your damage further.

On my latest play through with Samson, I picked up the Small Rock, Growth Hormones, Blood of the Martyr and a Lump of Coal, so my damage was nice and maxed. I then proceeded to face Gish, who spawns Clots quite frequently. Taking care to hit Gish just once and then proceed to kill a heap of clots before trying that again, it seemed like each of my hits still took down ~9px of Gish's health bar, which was exactly the mount of damage I did straight through the door.