What Affects the Different Steroid Half-Lives?

What Affects the Different Steroid Half-Lives?

Anabolic steroid half-lives are affected by a few different factors, the three primary of which are: route of administration, esterification, and resistance to metabolism.

The route of administration has a very significant impact on the half-life of an anabolic steroid. There are two primary routes of administration for anabolic steroids: oral and injectable. A third route would be transdermal patches, gels, or creams, which are methods of absorption through the skin.

However, anabolic steroid use for the purpose of physique and performance enhancement are almost always achieved through either oral administration, or injection. There are other less popular methods of administration as well that have been used, such as implantation pellets and sublingual and nasal applications, though they are far too rare to bother covering. The oral route of administration grants some of the shortest steroid half-lives among the different compounds. This is due to the fact that the vast majority of anabolic steroids are un-esterified, and are ingested in their pure and immediately active format. Because the oral route of administration presents no delay in the release of the anabolic steroid to the bloodstream, the hormones are instantaneously active and playing an active role in the body as soon as they hit the bloodstream (after they make the first pass through the liver). Although these oral anabolic steroids undergo a first pass through the liver, the amount of metabolism through the hepatic (liver) pathway does not slow down the release of the hormones into the bloodstream by much.

In fact, one of the reasons as to why oral steroid half-lives are much shorter than injectable steroid half-lives is because of the immediate exposure to liver metabolism, which facilitates faster metabolism and elimination of the hormone in and out of the body. Oral anabolic steroid half-lives generally range from 4 hours to 48 hours, depending on the anabolic steroid used.

Injectable anabolic steroids consist of two different types: oil-based injectables, which form a depot in the muscle tissue they are injected in, and slowly released from the injection site into the bloodstream. The second type are water-based injectables, known as suspensions, where the hormone is suspended in microcrystals that are in a water base. Once water-based suspensions are injected into muscle tissue, the microcrystals are slowly dispersed and released into the bloodstream into circulation. Injectable steroid half-lives are, for the most part, significantly longer than oral anabolic steroid half-lives. The reason for this is because of the nature of oil-based and water-based injections, which are designed to form a depot in the muscle tissue they are injected in, after which a slow release from the injection site into the bloodstream occurs in the hours or days after the injection. This extends the steroid half-lives quite significantly, but it is actually an additional factor that extends the injectable steroid half-lives even more: esterification. Nearly all anabolic steroids, especially oil-based, are esterified so as to deliberately extend their half-life and to make them more fat soluble in order to better dissolve in the carrier oil. The only exception to this is Testosterone Suspension and Winstrol (Stanozolol), both of which are injectable anabolic steroids that are not esterified at all. Injectable anabolic steroid half-lives generally range from 24 hours to as long as 15 days or more, depending on the anabolic steroid used and whether or not it is esterified (and what kind of ester is bound to it).

Esterification is perhaps the most influential contribution to the different steroid half-lives. Esterification is a process whereby a carboxylic acid is bound to an anabolic steroid’s 17-beta hydroxyl group. This type of bonding is known as esterification (also known as an ester bond). The carboxylic acids that are esterified to an anabolic steroid are of different and varying lengths, normally in the form of a carbon chain. The longer the carbon chain of the carboxylic acid, the longer it is, and therefore the longer the anabolic steroid’s half-life will be extended. Once the anabolic steroid is injected into the body, it is slowly released from the injection site into the bloodstream, and once in the bloodstream, the body’s esterase enzymes will break off the ester from the anabolic steroid. Longer ester bonds will require more time for these enzymes to free the hormone from the ester. But once the anabolic steroid hormone is broken free from the ester, what remains is a pure and active anabolic steroid that is free to do its work in the body. For example, pure and un-esterified Testosterone expresses a half-life of approximately 4 – 24 hours, but Testosterone Propionate expresses a half-life of 4.5 days, and Testosterone Enanthate expresses an even longer half-life of 7 – 10 days in the body. Esterification was deliberately devised by scientists back in the 1930s in order to deliberately extend the half-life of different anabolic steroids. Most anabolic steroids when un-esterified will express an extremely short half-life, making them very impractical for medical or clinical use due to the fact that they necessitate far too frequent injections for most people’s comfort. Esterification successfully extends the half-life of anabolic steroids to lengths that would require far less frequent injections, and therefore more comfortable injection schedules for patients.

Although nowhere near as influential as the previous three factors involved in the manipulation of steroid half-lives, the amount of resistance to the body’s metabolism has an effect on the half-life of a given anabolic steroid. For example, some oral anabolic steroids exhibit a half-life of 4 hours, while others will exhibit a half-life of 24 hours. The reason for this is because some anabolic steroids are much more resistant to metabolism in the liver (and/or elsewhere in the body), and therefore are not broken down as easily or as quickly. This means that the anabolic steroid in question would express a longer half-life in the body. Ultimately, however, all drugs, anabolic steroids, foods, chemicals, and compounds eventually undergo metabolism and elimination from the body – there is no such anabolic steroid or drug that will last forever in its active state in the body.