Maybe you should have still hung onto the formula. It might have been useful in the future if Donatello could perfect it. It was only temporary when he tested it so a human serum would only be temporary. So no need to worry about not being bullet proof.
shareYeah it was a boned headed decision.
Hang on to the vile and it's there for future use when Donnie concocts some brilliant use for it. Jumped the gun there Ralph
And I'm pretty sure they said they would still have their turtle powers anyway so there was literally no reason to not take the serum.
Plus after having a go at Leonardo for making the decision for everyone, Raphael does exactly the same thing.
I don't give a f*@K about a troll who doesn't pay for his opinion telling me how to review movies.