Testosterone enanthate addition

Wu FC, Balasubramanian R, Mulders TM, Coelingh-Bennink HJ. Oral progestogen combined with testosterone as a potential male contraceptive additive effects between desogestrel and testosterone enanthate in suppression of spermatogenesis, pituitary-testicular axis, and lipid metabolism. J Clin Endocrinol Metab 1999 84(l) 112-22. 

Testosterone This agent is ineffective orally because of inactivation by first-pass metabolism. As with the other sex steroids, testosterone is rapidly absorbed by the liver and other tissues, and is metabolized to relatively or completely inactive compounds that are excreted primarily in the urine but also in the feces. Testosterone and its C-17-esters (for example, testosterone cypi-onate or enanthate) are administered intramuscularly. [Note The addition of the esterified lipid makes the hormone more lipid-soluble, thereby increasing its duration of action.] Testosterone and its esters demonstrate a 1 1 relative ratio of androgenic to anabolic activity. 

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