Q: I have heard the terms subcutaneous injection (SubQ), intramuscular injection (IM), sublingual (SL) and transdermal (TD) for years, but what exactly is the absorption rate between one and the other when it comes to these various forms of transport. I know that everyone says that an IM injection is the only fast way to get something into your system, but what would be the harm in using something transdermal (using DMSO), for instance, as opposed to another method? Is it that big of a deal?

A: Good question. We’ll start with a method you didn’t mention…Intravenous injection (IV). While bodybuilders wouldn’t have occasion to use an IV injection unless they were using Nubain, IV injection is the fastest transport of all at about a 95-100% absorbtion rate. Subcutaneous injections are always given through the layers of skin and, if you have some body fat, goes into the layer of body fat attached to the skin directly, but yet avoids the muscle. With Sub-Q injections, an approximate 80% absorption rate can be expected. Absorption rate of an intramuscular (IM) injection is about 85-90%. The transdermal method (TD) of delivery nets a rate of absorption of anywhere between 40% and 70% depending upon how it is prepared. If it is prepared in patch form by a pharmaceutical company, the rate is highest, such as in a nicotine patch or birth control patch. If you prepare a Fina dose by removing elements from cattle pellets and purify it, then use DMSO to carry it into the skin, it’s probably going to hover around the 60% mark for a job well done and around 25% if you really botch the job. Sublingual (SL) preparations are absorbed as rapidly as IM injections at about 85-90%. There is one other method you may not want to have considered, and that’s the suppository rate of absorption. PR is the per rectum suppository method of transport and the absorption rate is about 75-80%. That doesn’t mean that you should stick a Fina preparation in your rectum to get a little more mileage out of it. You should only ever use actual pharmaceutical preparations in this area. On a final note, it merits mentioning that the body doesn’t distinguish between methods of transport at the point it receives the substance you’re trying to have absorbed. However, it’s best to use the method intended.