Pre-mixing protein shakes, how long do they last?

[Smoothie]

Its easier to pre mix my shakes for work and leave it in the fridge. Its a mrp mixed with skim milk. It would be in the fridge for about 3hrs before I drink it. Is this alright?
TIA!!

[SoulOfKoRea]

sure

[GhettoSmurf]

yes


ive left an MRP that i mixed in the fridge as long as 5 hours.

[RoidRage]

i read somewhere where the protein is ok mixed up for up to 8 hours