Hi,it could the shake itself....they all taste different ...you have to find one you like....take it from me..body fortress at walmart..is not chalky..no after taste...I mixed it with blue almond milk...makes it creamy like a shake..plus I can't drink it unless it coldddd so I put it in the freezer for like ten mins, while I get dressed......I tried the chocolate, chocolate peanut butter...cookies and cream. ,, and vanilla...try it...and don't try to gulp them...take your time...