Creatine is, by far, the most thoroughly researched and widely used supplement out there. And for one very good reason: It works. For all its popularity, it's not really surprising that there are so many forms of creatine available. Not only are there different brands but companies extract their creatine powder from a variety of sources or even offer it in an assortment of chemical structures. Faced with this array of choices, plenty of fitness enthusiasts simply assume that “creatine is creatine” and pick up whatever is cheap and convenient. Is this strategy working, though? Is all creatine actually created equal or does it matter what type of creatine you use? Start at the Beginning To understand a key difference in most creatine powders – one that often goes ignored – we first need to be clear on where creatine comes from. Although most people are chiefly familiar with the supplement, creatine is actually a substance that occurs naturally in the human body and plays a powerful role in your energy production system. Dietarily speaking, creatine can be found in meats, eggs, fish and other animal products. Most often, creatine powder is extracted from animal sources. This presents a problem for the vegans out there, however. In that case, you'll want to be sure that you find a synthetic creatine, like Naked Creatine, which is chemically and functionally identical to the animal-based varieties. As is often the case with supplements, you'll also want to be sure that your creatine powder is not contaminated. A 2011 study conducted in Italy tested 33 different creatine powders for purity and found that many contained high levels of the by-products creatinine and dicyandiamide. While neither of these substances are considered toxic, they simply shouldn't be there. Their presence indicates an impure and poorly processed creatine supplement. Of greater concern is that fact that several of the products also showed considerable levels of the toxic heavy metal mercury. Before you even consider a creatine powder, then, make sure that you trust the brand. Different Shapes Next, we need to consider all the many forms that creatine comes in – a list that keeps growing. In large part, this has to do with the way that the creatine is processed and what other substances it is bonded with. The original form of creatine supplements, however, is creatine monohydrate – the type used in most of the studies. Beyond that, you're likely to encounter Creatine Magnesium chelate, Creatine pyruvate, Creatine Citrate, Creapure, Creatine Nitrate, Buffered Creatine (Kre-Alkalyn), Creatine Hydrochloride (Con-Cret), Creatine Hydrochloride, Creatine Ethyl Ester and many others. Each of these forms claim their own unique perks, but the most common differences have to do with absorption and solubility. First, let's talk about absorption. Creatine monohydrate remains stable throughout digestion and metabolism, making it to your muscles while maintaining its useable form. Some of these creatine varieties, like Creatine Ethyl Ester, do not even do that – simply degrading into useless byproducts. Many of forms of creatine claim a faster absorption rate, however. Here's the thing: the benefits of creatine are based on saturation, with no acute effects. The speed at which the molecule is broken down, then, doesn't matter. Ultimately... While some forms of creatine do tend to dissolve more easily in water, or may be bonded with other helpful substances, these extra perks tend to come along with a much higher price tag. When all the types of creatine are compared, then, creatine monohydrate offers the best value, with a long history of scientific evidence behind its use. Read More: Does Creatine Work? Is Creatine Safe? Liquid Creatine vs Powdered Creatine