at 8 months personally i would not try Nutramigen, Aptimil pepti might be a better start.
Nutramigen is FOUL! my pead said that at almost 3 months when Alyssa tried it she was almost too old to introduce it
I have tried every milk my babies have had, rangeing from breast (so i would know if the EBM was off) to normal formula, to soya then nutramigen and Neocate
Soya tastes hardly different to normal formula, Nutramigen omg!!! Neocate a bit blah but after Nutramigen very nice lol