Dydrogesterone is an orally active progestogen which acts directly on the uterus, producing a complete secretory endometrium in an estrogen-primed uterus. At therapeutic levels, dydrogesterone has no contraceptive effect as it does not inhibit or interfere with ovulation or the corpus luteum. Furthermore, dydrogesterone is non-androgenic, non-estrogenic, non-corticoid, non-anabolic and is not excreted as pregnanediol. Dydrogesterone helps to regulate the healthy growth and normal shedding of the uterus lining. Therefore, it may be useful in the treatment of menstrual disorders such as absent, irregular or painful menstrual periods, infertility, premenstrual syndrome and endometriosis. Dydrogesterone works by regulating the healthy growth and normal shedding of the womb lining by acting on progesterone receptors in the uterus. Used to treat irregular duration of cycles and irregular occurrence and duration of periods caused by progesterone deficiency. Also used to prevent natural abortion in patients who have a history of habitual abortions. Dydrogesterone was first introduced to the market in 1961, and is currently approved in over 100 countries world-wide. Banned in the USA and wthdrawn from the UK, but still used in other countries.

Norethynodrel is a steroidal progestin of the 19-nortestosterone group and an isomer of norethisterone. Norethynodrel is a progesteron agonist with very weak estrogenic activiry. Noretynodrel was introduced in 1957 in Enovid, a combination formulation of noretynodrel and mestranol, for the treatment of gynecological and menstrual disorders.A few years later, in May 1960, Enovid was also approved as the first oral contraceptive.

Pregnenolone sulfate is an endogenous neurosteroid with excitatory effects in the brain, acting as a potent negative allosteric modulator of the GABAA receptor, a positive allosteric modulator of the NMDA receptor, and activator of transient receptor potential cation channel TRPM1 and TRPM3. In the model of schizophrenia, treatment with pregnenolone sulfate normalized the hyperlocomotion and stereotypic bouts, and rescued the PPI deficits of dopamine transporter knockout mice. Promnesic properties of pregnenolone sulfate were demonstrated in rat models of spatial memory performance.

Ethisterone is a metabolite of danazol. Ethisterone is a progestogen hormone. The first orally active progestin, Ethisterone (brand names Pranone, Progestoral, Lutocylol, Proluton C), also known as 17α-ethinyltestosterone, pregneninolone, or anhydrohydroxyprogesterone, is a steroidal progestin with androgenic activity which is derived from testosterone and was introduced for medical use in 1939. Ethisterone is indicated for progesterone supplementation or replacement as part of an Assisted Reproductive Technology (ART) treatment for infertile women with progesterone deficiency and for the treatment of secondary amenorrhea. Also used as a female contraceptive.

Desoxycorticosterone pivalate (DOCP) is a mineralocorticoid hormone and an analog of desoxycorticosterone. DOCP is a long-acting ester of desoxycorticosterone acetate (DOCA) which is recognized as having the same qualitative effects as the natural mineralocorticoid hormone aldosterone. It’s used as Percorten-V for replacement therapy for the mineralocorticoid deficit in dogs with primary adrenocortical insufficiency. Percorten-V is only available in the U.S., Canada, Australia and recently, Denmark. Percorten was originally developed for the treatment of Addison's disease in humans but the demand for it decreased significantly once Florinef was available. Unaware that their product was being prescribed “off-label” for the treatment of canine Addison’s Disease and faced with a decreased demand for Percorten, the manufacturer *almost* discontinued production until the veterinary community rose up and voiced their distress. Field trials were run and the FDA approved the use of Percorten-V (the "v" is for veterinary). DOCP like other adrenocorticoid hormones is thought to act by controlling the rate of synthesis of proteins. It reacts with receptor proteins in the cytoplasm to form a steroid-receptor complex. This complex moves into the nucleus, where it binds to chromatin that result in genetic transcription of cellular DNA to messenger RNA. The steroid hormones appear to induce transcription and synthesis of specific proteins, which produce the physiologic effects seen after administration. The most important effect of DOCP is to increase the rate of renal tubular absorption of sodium. This effect is seen most intensely in the thick portion of the ascending limb of the loop of Henle. It also increases sodium absorption in the proximal convoluted tubule but this effect is less important in sodium retention. Chloride follows the sodium out of the renal tubule. Another important effect of DOCP is enhanced renal excretion of potassium. This effect is driven by the resorption of sodium that pulls potassium from the extracellular fluid into the renal tubules, thus promoting potassium excretion.

Gestodene (17alpa-ethynyl-13beta-ethyl-17beta-hydroxy-4,15-gonadien-3-one) is the most potent synthetic progestin currently available and it is widely used as a fertility regulating agent in a number of contraceptive formulations because of its high effectiveness, safety and acceptability. Products containing gestoden include Meliane, which contains 20 ug of ethinylestradiol and 75 ug of gestodene; and Gynera, which contains 30 ug of ethinylestradiol and 75 ug of gestodene. Gestodene is androgenically neutral, meaning that contraceptive pills containing gestodene do not exhibit the androgenic side effects (e.g. acne, hirsutism, weight gain) often associated with second-generation contraceptive pills. Gestodene displays a high binding affinity to the progesterone receptor, also binds to adrogen and glucocorticoid receptors but no measurable affinity for the estrogen receptor.

Melengestrol is a steroidal progestin and antineoplastic agent which was never marketed. An acylated derivative, melengestrol acetate, is used as a growth promoter in animals. Melengestrol acetate (MGA) is one of six steroidal hormone growth promoters approved for use in Canada and USA. These products are used to improve growth rate and feed efficiency, as well as to suppress estrus in beef heifers (CFIA 2008). They are not approved for use in any species other than beef cattle meant for slaughter. MGA is the only drug of its kind that is administered in animal feed, and its labelled dose in Canada is 0.4mg per heifer per day (CFIA 2008). A mandatory withdrawal of 2 days before slaughter is applied to any animal that is administered MGA.

Trenbolone is an anabolic steroid. It is used on livestock to increase muscle growth and appetite. Trenbolone compounds have a binding affinity for the androgen receptor three times as high as that of testosterone. Once metabolized, the drugs have the effect of increasing nitrogen uptake by muscles, leading to an increase in the rate of protein synthesis. It also has the secondary effects of stimulating appetite, reducing the amount of fat being deposited in the body, and decreasing the rate of catabolism. Short-term side effects include insomnia, high blood pressure, increased aggression, night sweats, and libido.

Norgestomet is a synthetic derivative of progesterone with improved oral activity due to its 17α-acetate side chain. In veterinary medicine norgestomet is used for the synchronisation of oestrus in cattle. It is administered as a subcutaneous ear implant (containing 3 mg norgestomet; to be removed after 9 to 10 days), in combination with a single intramuscular injection containing 3 mg norgestomet and 5 mg oestradiol valerate. The injection is to be given immediately after application of the implant. Norgestomet is not used in human medicine. It is a steroidal progestin of the 19-norprogesterone group.