Here is the list of ingredients I found on NC:
Aqua/water, cetearyl alcohol, cetyl esters, amodimethicone, behentrimonium chloride, parfum/fragrance, methylparaben, trideceth-12, cocos nucifera/coconut oil, butylphenyl methylpropional, propylene glycol, limonene, linalool, cetrimonium chloride, chlorhexidine dihydrodchloride, 2-oleamido-1,3-octadecanediol, hydrolyzed soy protein, oleth-10, citronellol, bambusa vulgaris extract, alpha isomethyl ionone, disodium cocoamphodipropionate, coumarin, citral, BHT, sorbitol, octylacrylamide/acrylates/butylamionethyl methacrylate copolymer, geraniol, phenoxyethanol, lecithin, phosphoric acid, polyquaternium-10, ethylparaben, disodium EDTA
Not sure if this is the most current...Looks like there is soy protein but it's in the middlle of the list...My hair can be sensitive to protein but I really love this stuff. Doesn't look like there is any castor oil in it...
It really depends on your hair...Some people swear it does not build up on them, and have no issues...I think I read somewhere that once amodimethicone is deposited on the hair, it does not continue to build up...Anyways, if you low poo every now and again, you shouldn't have an issue...Something like coco betaine should be enough to get it out.