Medroxyprogesterone acetate (INN, USAN, BAN), also known as 17α-hydroxy-6α-methylprogesterone acetate, and commonly abbreviated as MPA, is a steroidal progestin, a synthetic variant of the human hormone progesterone. Medroxyprogesterone acetate (MPA) administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. Androgenic and anabolic effects have been noted, but the drug is apparently devoid of significant estrogenic activity. While parenterally administered MPA inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. MPA is a more potent derivative of its parent compound medroxyprogesterone (MP). While medroxyprogesterone is sometimes used as a synonym for medroxyprogesterone acetate, what is normally being administered is MPA and not MP. Used as a contraceptive and to treat secondary amenorrhea, abnormal uterine bleeding, pain associated with endometriosis, endometrial and renal cell carcinomas, paraphilia in males, GnRH-dependent forms of precocious puberty, as well as to prevent endometrial changes associated with estrogens. Progestins diffuse freely into target cells in the female reproductive tract, mammary gland, hypothalamus, and the pituitary and bind to the progesterone receptor. Once bound to the receptor, progestins slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH surge.

Osaterone acetate (previously known as TZP-4238), a synthetic steroidal anti-androgen agent. Osaterone acetate is used in veterinary in Europe in the treatment of benign prostatic hyperplasia (BPH) in male dogs. Osaterone acetate inhibits the effects of an excess of male hormone (testosterone) through various mechanisms. It competitively prevents the binding of androgens to their prostatic receptors and blocks the transport of testosterone into the prostate. Osaterone acetate was also investigated in Japan in the treatment of prostate cancer and BPH and, in addition, was studied in postmenopausal osteoporosis in humans. However, these studies were discontinued.

Phorbol 12-myristate 13-acetate (PMA) also commonly known as 12-O-Tetradecanoylphorbol-13-acetate (TPA) is a phorbol ester that is commonly used to activate phospholipid-dependent protein kinase (protein kinase C). PMA/ TPA possesses potential antineoplastic effects and was studied in phase II clinical trials together with dexamethasone in patients with relapsed or refractory acute myeloid leukemia. In addition, PMA/ TPA participated in phase I trial for treating patients with hematologic cancer or bone marrow disorder that has not responded to previous treatment. Nevertheless, both clinical trials were terminated. Besides, PMA/ TPA was studied in patients with solid tumors, which had depressed white blood cell and neutrophil counts because of prior treatment with cytotoxic cancer chemotherapeutic drugs. It was shown, that the drug increased the low white blood cell and neutrophil counts toward the normal range.

Phenylacetate is the ester of a phenol and acetic acid. It is a metabolite of anticancer drug phenylbutyrate (PB), natural neurotransmitter phenylethylamine. Naturally, it is an odorant found in strawberries, passion fruit, and black tea. Phenylacetate level in urine was used as a marker for the diagnosis of some forms of unipolar major depressive disorders. Phenylacetate is used as a tool substrate to study esterase activity in the blood of patients in clinical studies of the effect of nutritional supplements on paraoxonase-1 levels.