Anabolic steroids differ in their characteristics, which means there are steroids that are only suitable for specific uses. For instance, Trenbolone is not recommended for bulking but it is an outstanding fat burner. This makes it perfect for a lean mass cycle or a cutting cycle. Always take the side effects of a particular compound into consideration whenever you plan a stack. Do not combine anabolic steroids that show similar side effects. For example, never combine Anapolon and Dianabol because they are already quite toxic and if you combine them, the toxicity will increase exponentially and cause serious damage to your body.
Is there anything to worry about?
Yes there is. In fact, if you abuse the use of fat burners then there is certainly a lot to be worried about. You would be preparing yourself for side-effects which could be short-term, long-term, reversible or irreversible. Sounds horrifying? It is intended to be so because unless you use these things under proper guidance of an expert or medical practitioner, you are making a good case of what not to do. There have been cases in the past when people go to extremes in their desperation and suffer from side-effects. It is generally not the product that has to be blamed but the greed of the user for overnight success.
More specifically, the methylcobalamin form of B12 is recommended, as it has been shown to be the most effective. Taking B12 gives you a huge boost of energy while training, and more importantly, greatly helps your recovery.