Testosterone cypionate

Absorption

Testosterone cypionate is an esterified anabolic which allows it to present a greater degree of solubility in fats and thus, the release and absorption occur in a slow rate compare to homologous molecules. Intramuscular administration of 200 mg of testosterone cypionate produced a mean supratherapeutic Cmax of 1122 ng/dl which occurred 4-5 days post-injection. After the fifth day, the levels of testosterone cypionate in plasma went down reaching an average of 400 ng/dl.

Toxicity

Preclinical studies with testosterone implants induced cervical-uterine tumors in mice which metastasized in some cases. Some reports indicate that administration of testosterone cypionate in females can augment the susceptibility to hepatoma as well as increase the number of tumors. Clinical studies have reported cases of hepatocellular carcinoma in long-term high-dose therapy.

The Uses of Testosterone cypionate

Testosterone Cypionate is an anabolic steroid with androgenic properties. Testosterone Cypionate is used for testosterone therapy in males with hypogonadism. Controlled Substance.

Background

Testosterone cypionate is a synthetic derivative of testosterone in the form of an oil-soluble 17 (beta)-cyclopentylpropionate ester. Its benefit compared to other testosterone derivatives is the slow rate of release after injection and longer half-life. It was developed by the company Pharmacia and Upjohn and FDA approved on July 25, 1979.

Indications

Testosterone cypionate is used in males that present conditions derived from a deficiency or absence of endogenous testosterone. These conditions are 1) primary hypogonadism, defined as the testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; and 2) hypogonadotropic hypogonadism characterized by idiopathic gonadotropin, LHRH deficiency or pituitary-hypothalamic injury from tumors, trauma or radiation.

Pharmacokinetics

Administration of ester derivatives of testosterone as testosterone cypionate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. The continuous variation in plasma testosterone after intramuscular administration of testosterone cypionate results in fluctuations in mood and libido as well as some local inflammation.

Metabolism

To start its activity, testosterone cypionate has to be processed by enzymes in the bloodstream. These enzymes will break the bond between the cypionate ester moiety and the testosterone. Once separated, testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT). Testosterone is metabolized to DHT by steroid 5α-reductase in skin, liver and urogenital tract. In reproductive tissues DHT is further metabolized to androstanediol.