Instruct: Classify Amazon reviews into positive or negative sentiment
Query: wrong kind of B12

What I like about Twinlab products is that they come in glass, so I'm not trashing the planet with more plastic. I've been happy with other Twinlab products for years.Sadly, I've learned about a serious problem with this B vitamin product. It contains the wrong form of B12--cyanocobalamin. According to the information I've received, this form cannot be digested without stealing methyl needed for other purposes. The form of B12 that is usable and best digested by the body is methylcobalamin. For most people taking B12 orally is not as effective as sublingually, or better yet, in a patch. I'm sorry I've been taking this, as it seems that taking cyanocobalamin could be worse for my usable B12 levels than taking no supplement at all.