Package : 10ml vial contains 100mg/ml  
Substance : Testosterone propionate  
Profile : NomadLab ® Testosterone propionate

As we all know, Testosterone was the first steroid to be synthesized. Now, it remains the gold standard of all steroids. First, we’ll discuss Testosterone in general, and in depth, then we’ll examine exactly how (and what) the propionate ester is (together, testosterone propionate is often referred to as just "prop" or "test prop").

Testosterone’s anabolic/androgenic ratio is 1:1 meaning it is exactly as anabolic as it is androgenic. Actually, testosterone is the steroid which all anabolic/androgenic ratios are based on. If a steroid is 2:1, then it is, compared with testosterone’s ratio, doubly as anabolic as it is androgenic. Hence, we see from testosterone’s ratio, it is both quite anabolic as well as androgenic.

So how exactly does Testosterone build muscle? Well, Testosterone promotes nitrogen retention in the muscle, and the more nitrogen the muscles holds the more protein the muscle stores, and the bigger the muscle gets. Testosterone can also increase the levels of another anabolic hormone, IGF-1, in muscle tissue. IGF-1 is, alone, highly anabolic and can promote muscle growth. It is responsible for much of the anabolic activity of Growth Hormone (GH). IGF-1 is also one of the few hormones positively correlated with both muscle cell hyperplasia and hyperphasia (this means it both creates more muscle fibers as well as bigger fibers). All of this leads me to speculate that for pure mass, IGF-1, GH, and Testosterone would be a very effective combination. Testosterone also has the amazing ability to increase the activity of satellite cells. These cells play a very active role in repairing damaged muscle. Testosterone also binds to the androgen receptor (A.R.) to promote all of the A.R dependant mechanisms for muscle gain and fat loss, but clearly, as we’ve seen, this isn’t the only mechanism by which it promotes growth.

Testosterone has a profound ability to protect your hard earned muscle from the catabolic (muscle wasting) glucocorticoid hormones, and increase red blood cell production, and as you may know, a higher RBC count may improve endurance via better oxygenated blood. The former trait increases nitrogen retention and muscle building while the latter can improve recovery from strenuous physical activity, as well as increase endurance and tolerance to strenuous exercise.

Testosterone occurs naturally in both the male and female body, as insofar as drug testing for it, typical tests don’t work (i.e. testing for metabolites). Testosterone can be tested for on a testosterone/epitestosterone ratio, a failing result usually being anything over 6 to 1, but there are other more effective tests currently in use as well as being developed by the usual party-poopers in the IOC and FDA. Noteworthy is that if you are using low doses of this drug and stop taking it 36-48 hours before a Test/EpiTest analysis, you can still pass! 
Testosterone, once in the body, can be converted to both estrogen (via a process known as aromatization) as well as DHT. Estrogen is the main culprit for many side effects such as gyno, water retention, etc...while DHT is often blamed for hair loss and prostate enlargement. Naturally there are ways to combat this, such as using an anti-estrogenic compound along with testosterone, or even an estrogen blocker. DHT can be combated (on the scalp, to prevent hair loss) with compounds such as Ketoconazole shampoo (sold under the trade name Nizoral) as well as Finasteride (sold as Proscar in the 5mg version and as Propecia as 1mg tablets). Interestingly, this shampoo can also be used topically to combat acne on the face (or even the back if you’re really flexible). Both of these methods for preventing hair loss and acne are reasonably effective. However, if you are not prone to hair loss, they may be wholly unnecessary. Male Pattern Baldness (MPB) is carried by the X chromosome, so if your mother’s family boasts men with full heads of hair, then you are probably safe (unless those full heads of hair are all mullets). Naturally, as with most other steroids, your lipid profile is going to suffer a bit while on testosterone as is your blood pressure. This, of course is nothing that can’t be controlled by watching your diet and doing your cardio, at least for the duration of the typical cycle (which for arguments sake, I′ll assume is +/- 12 weeks). Let’s be totally honest, here, even a modest amount of exercise will improve your blood pressure and lipid profile, and if you aren’t exercising, then why are you taking steroids?

To combat the aromatization of testosterone, you can simply take an aromatase inhibitor such as Arimidex. This and other Anti-estrogenic compounds are generally considered a must with testosterone doses over   a gram per week (500mgs). Also among side effects (as if acne and going bald aren’t enough) is increased aggression. This is a hotly debated issue in steroid culture. Generally the consensus is that if you are prone to being a jerk, you’ll be a bigger jerk ...if you aren’t, then your temper will not get much worse (this is supported by research as well Also, high levels of test are generally only associated with aggression and anti-social behavior in males with lower intelligence.

Also, as with most steroids, injected testosterone will inhibit your natural test levels and HPTA (Hypothalamic Pituitary Testicular Axis). A mere hundred mgs of test/week takes about 5-6 weeks to shut the HPTA, and 250-500mgs shuts you down by week 2.