This mod exists because I kept grabbing the Cursed Eye on accident, or mistaking Ipecac for Rubber Cement, or forgetting which Guppy item set my health down to 1.
The point of the mod isn't to make you avoid these items, just to give you a visual indicator that you should put thought into whether you want its particular effect.

The affected items:
My Reflection
Number One
Dr. Fetus
Chocolate Milk
Dead Cat
Mom's Knife
Ipecac
Epic Fetus
Antigravity
Tiny Planet
Experimental Treatment
Missingno
Bob's Brain
Cursed Eye
The Ludovico Technique
Soy Milk
Strange Attractor

Additionally, the Tick trinket is affected, since it carries the penalty of being undroppable.

Big thanks to the http://platinumgod.co.uk/rebirth site for making checking everything so simple.