Has anyone tried a formula thickener ?

If so, did it work for you? I purchased a can of karicare formula thickener today. My 5 week old son is on karicare gold formula but is starting to throw up quite regularly. still feeding great and putting on lots of weight, a little too much weight to be honest. Another parent suggested that we tried this thickener as she has had great success in stopping all the spit up for her son. Has anyone else tried it? How did it go. I am going to try just one scoop in a bottle tonight, I thought that maybe f he digests his food a little slower he may drink a bit less. he is wanting far more than the recommended amounts and is putting on quite a bit of weight. What do you all think?