Testosterone is a steroid sex hormone found in both men and women. In men, testosterone is produced primarily by the Leydig (interstitial) cells of the testes when stimulated by luteinizing hormone (LH). It functions to stimulate spermatogenesis, promote physical and functional maturation of spermatozoa, maintain accessory organs of the male reproductive tract, support development of secondary sexual characteristics, stimulate growth and metabolism throughout the body and influence brain development by stimulating sexual behaviors and sexual drive. In women, testosterone is produced by the ovaries (25%), adrenals (25%) and via peripheral conversion from androstenedione (50%). Testerone in women functions to maintain libido and general wellbeing. Testosterone exerts a negative feedback mechanism on pituitary release of LH and follicle-stimulating hormone (FSH). Testosterone may be further converted to dihydrotestosterone or estradiol depending on the tissue. The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects. Testosterone is used as hormone replacement or substitution of diminished or absent endogenous testosterone. Use in males: For management of congenital or acquired hypogonadism, hypogonadism associated with HIV infection, and male climacteric (andopause). Use in females: For palliative treatment of androgen-responsive, advanced, inoperable, metastatis (skeletal) carcinoma of the breast in women who are 1-5 years postmenopausal; testosterone esters may be used in combination with estrogens in the management of moderate to severe vasomotor symptoms associated with menopause in women who do not respond to adequately to estrogen therapy alone.

Undecanoic acid (UDA) is a fatty acid with significant antimycotic activity. Undecanoic acid is a straight-chain, eleven-carbon saturated medium-chain fatty acid found in body fluids; the most fungitoxic of the C7:0 - C18:0 fatty acid series. It has a role as a human metabolite and an antifungal agent. It is a straight-chain saturated fatty acid and a medium-chain fatty acid. It is a conjugate acid of an undecanoate. It derives from a hydride of an undecane. Undecanoic acid inhibited the production of exocellular lipase and keratinase but stimulated the production of exocellular phospholipase A in T. rubrum undecanoic acid-resistant mutant (udar). At its minimum inhibitory concentration, undecanoic acid inhibits biosynthesis of phosphatidyl serine, phosphatidyl ethanolamine and polyphosphoinositol but does not inhibit the synthesis of phosphatidyl glycerol, phosphatidyl choline, phosphatidyl inositol and phosphatidic acid in Trichophyton rubrum. At higher concentration, however UDA inhibits biosynthesis of all phosphatides present in this dermatophyte. UDA also affects catabolism of these phosphatides. This inhibitory effect of UDA may be partially responsible for its toxic action on T. rubrum.