Test 400 is an oil-based injectable blend of three separate esters of the drug Testosterone. Test 400 contains the following esters of Testosterone, all of which are considered to be “long acting”; Cypionate (150mg), Enanthate (150mg), and Undecanoate (100mg). The 3 combined esters of this drug makes its release fairly slow, and therefore requires injections to be much less frequent than they would be if the user was administering a drug with a faster-acting ester attached to it such as Testosterone Propionate. Athletes using this steroid (Test 400) often find that administering the drug twice per week (Monday/Friday, for example), is very sufficient for maintaining steady blood and hormonal level. Theoretically, the user could administer Test 400 once every 7 to 10 days and still maintain steady and stable hormonal levels. Test 400, comprised mainly of Testosterone Enanthate and Testosterone Cypionate, is one of the most common anabolic hormones that exists, and is also considered one of the most basic as well. Due to this, bodybuilders and athletes alike often consider it the base steroid to most all cycles. Test 400 is both anabolic and androgenic in nature. Users of this steroid will notice a dramatic gain in muscle size and strength, as well as an overall sense of well-being with an increase in libido. Test 400 aromatizes very easily and therefore estrogen build-up and side effects can become an issue for users sensitive to these problems, or those choosing to use a high dose of this compound. Therefore, when using Testosterone Enanthate, bodybuilders often choose in incorporate an anti-estrogen such as Nolvadex, Proviron, or Arimidex to help keep estrogen-related side effects to a minimum. Extremely sensitive users, or users indulging in high(er) doses might find that stronger anti-estrogens such as Letrozole or Aromasin are more suitable. Androgenic side effects such as oily skin are also possible while taking Testosterone Enanthate. Bodybuilders looking to bulk up and see dramatic increases in size and strength will often combine Test 400 with other drugs such as Nandrolone Decanoate, Boldenone Undecylenate, Dianabol, and/or Anadrol.