Welcome to the wonderful world of SCIENCE!!

Testosterone esthers break down as followed: they consist of the actual test molecule, with a carbon chain attached. The chain controls the partition co-efficient, meaning how soluble it will be once in your bloodstream. Pay in mind the larger the chain, the longer the esther, the less soluble it is in water, and the longer the half life.

For example here's a lot of peoples favorite test, Propionate. Prop is a three carbon chain esther: c-c-c. meaning there are three carbons in the chain. The half life of prop is the shortest esther when comparing them to enanthate, cypionate. Enanthate has eight: c-c-c-c-c-c-c-c. It makes enanthate form significantly less soluble in water and slows the test's release in the bloodstream. This is what accounts for the longer half life compared to prop.
Esthers work in a similar manner with release in the bloodstream.
There are two main types of enzymes that act to cleave off the esther and activate the test. Enzymes called estherases cut pieces of the esther off the test, releasing the chemical and allowing it to do its job. Another type called hydrolysate which is a water breaking enzyme, aids the breaking of the esther from the test molecule as well. Once the esther's broken from the test molecule, the molecule becomes active.

The bloodstream which test circulates is called the "medium". These enzymes move about in the medium and directly affect the release of "active" testosterone in the blood by esther cutting
The Basic Test Esthers, Speed the release in the blood, and PIP caused by the esther.

The length of the esther affects the half-life in the bloodstream. The longer the chain, the longer the half-life. This will be useful when trying to keep even blood levels for muscle growth and recovery. The half-lives of the most common esthers are as follows:

Test Suspension or TNE- this is pure test in sterilized water. There is no esther attached and the test is active at 100%, from injection. It is suspended in crystals in the solution and is why the "burn" occurs upon injection. The crystals dissolve extremely fast on injection since there is no added partition coefficient because there is no esther attached slowing down the absorption. 100mg of TNE is 100mg of active test. The half-life is 12-36 hours depending on the state of your metabolism and any other aas already in your system.

Testosterone Prop. One of the most popular esthers around and the shortest available chain in an injectable. The esther is from propionic acid, which is an acid that has the potential to cause massive pip at the injection site. Prop is used for site injection because it has a tendency to cause an intense localized swelling of the site in a lot of people. The reason prop burns is due to the short esther. The shorter the esther, the more irritation and "burn" to the muscle. here is a good example (I used to be allergic to bees so this is how I know this info) Bee venom, is a C1, prop is a C3 The half-life of prop is 48-72 hours, The problem with using shorter esthers is you need to inject ED or EOD and the pip from this . Advantage faster absorption into the bloodstream.

The smaller esther, weigh less. It's is important because it brings another advantage to the table. If the esther weighs less, the amount of test per ml is more. Quick example, TNE is 100% test. No esther. The short chain prop, is about 74% test (depending upon source). Meaning if you take a typical 1cc shot of prop at 100mg/cc, it is only 74mg of testosterone and 26 milligrams of esther. Enanthate on the other hand, is about 55%. 45% percent of the weight of a given amount of test enanthate is the enanthate esther, not the active test. A typical 200mg/cc shot of enanthate contains 110mg of active test. If you used a shorter acting esther, and got better results than using heavy doses of longer acting, this is the reason. You were getting more “active” test in your blood with what might have appeared to be less “overall” or gross mg dosage.

Another factor to consider is that you have more interacting with your receptors at a time with short acting esthers. You need to understand drug half life if you are to get the most “bang for your buck.” With respect to your health and longevity, this is extremely important. Why take more, if less works just as well.

Enanthate is one of the most available tests out there. The half life of enanthate, ranges from 4-7 days. Test enanthate isn't known to cause irritation. If you want a high and consistent blood level and don't want to constantly pin, enanthate is your answer. Every four to five days is good enough to maintain blood levels.
When pinning this way; it will cause a significant build up of test in your bloodstream that will not increase until four or five weeks. Taking a 400mg injection, and four days later, you still have 200mg working from the last injection. The third then adds another four hundred and the first is still not used up. You may have over a gram or more in your bloodstream before you know it. So be careful, and keep that in mind when figuring out your dosages.

Test Cypionate or cyp is interchangeable with enanthate. They differ by one carbon chain length which does not significantly affect the duration of action of these drugs. For that reason I will not get into any more details on cyp.

Happy reading and stay safe; the more you learn, the better you will be at choosing the right path in this game.