Capromorelin is a potent ghrelin receptor agonist. Capromorelin is indicated for appetite stimulation in dogs. Plasma insulin-like growth factor-I (IGF-I) was elevated progressively over a 5-d course of daily oral dosing in dogs. In healthy older adults at risk for functional decline, administration of the capromorelin may improve body composition and physical function. Adverse events included fatigue, insomnia, and small increases in fasting glucose, glycosylated hemoglobin, and indices of insulin resistance.

Estriol (E3), also spelled oestriol, is a steroid, a weak agonist of the estrogen receptors ERα and ERβ., and a minor female sex hormone. According to in vitro study, the relative binding affinity (RBA) of estriol for the human ERα and ERβ was 11.3% and 17.6% of that estradiol, respectively, and the relative transactivational capacity of estrone at the ERα and ERβ was 10.6% and 16.6% of that of estradiol, respectively. Estriol is marketed widely in Europe and elsewhere throughout the world under the brand names Ovestin, Ortho-Gynest, and a variety of others. It is available in oral tablet, vaginal cream, and vaginal suppository form, and is used in menopausal hormone therapy for the treatment of menopausal symptoms. Estriol is also available in some countries as estriol succinate (brand name Synapause), a dosage-equivalent ester prodrug of estriol. Estriol and estriol succinate are not approved for use in the United States and Canada, although they have been produced and sold by compounding pharmacies in North America for use as a component of bioidentical hormone therapy. Estriol can be measured in maternal blood or urine and can be used as a marker of fetal health and well-being. If levels of unconjugated estriol (uE3 or free estriol) are abnormally low in a pregnant woman, this may indicate chromosomal or congenital anomalies like Down syndrome or Edward's syndrome. It is included as part of the triple test and quadruple test for antenatal screening for fetal anomalies.

Zeranol is a non-steroidal anabolic growth promoter with potent estrogenic activity that is widely used as a growth promoter in the US beef industry. It is a mycotoxin, derived from fungi in the Fusarium family, it is an estrogen agonist. Zeranol is approved for use as a growth promoter in livestock, including beef cattle, in the United States. In Canada, it is approved for use in beef cattle only. Zeranol was officially banned in Europe due to safety concerns because of its potential carcinogenic and endocrine-disrupting biological activity. Merck Animal Health markets zeranol under the brand name Ralgro. It has being shown, that zeranol may increase cancer cell proliferation in already existing breast cancer.

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.

Deslorelin is an GnRH agonist used in veterinary. It effects contraception by temporarily suppressing the reproductive endocrine system and preventing production of pituitary (FSH and LH) and gonadal hormones (estradiol and progesterone in females and testosterone in males). The observed effects are similar to those following ovariectomy or castration, but are reversed after the hormone content of the implant is depleted or the implant is removed. As an agonist, deslorelin first stimulates the reproductive system, which can result in estrus and ovulation in females or temporary enhancement of testosterone and semen production in males. Then, down-regulation follows the initial period of stimulation. Although deslorelin can also be an effective contraceptive in males of some species, manufacturer recommends its use primarily in females, since monitoring efficacy in females by suppression of estrous behavior or of gonadal steroids in feces is more straightforward than ensuring continued absence of sperm in males, since most institutions cannot perform regular semen collections. It can, however, be used to ameliorate aggression in males of some species, but higher dosages are usually needed. While the major application of deslorelin was initially male contraception, due to its two differing actions, either the stimulation of oestrus or the sterilization of fertility, its use has been increasing in the bitch as well. SUPRELORIN® F (deslorelin acetate) Implant is a once-yearly, subcutaneous implant that assists in the management of adrenal disease in ferrets.

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.

Isoflupredone is a veterinary drug used in cows, pigs and horses for the treatment of wide range of conditions: ketosis, musculoskeletal disorders, hypersensitivity, infections, inflammatory diseases, etc. The drug belongs to the class of corticosteroids and exerts its therapeutic effect by binding to glucocorticoid and mineralocorticoid receptors of animals.

Trimegestone is a 19-norpregnane progestin. It has a potent progesterone receptor and very low androgen receptor affinities but no detectable affinity to oestrogen receptor. Trimegestone has been developed for use in conjunction with oestrogen and 17-beta-estradiol for postmenopausal hormone replacement therapy. In vitro studies have shown that trimegestone can inhibit cytochrome P450 2C19 (CYP2C19). Although its clinical importance is unknown, trimegestone can moderately elevate the plasma concentration of drugs metabolized through CYP2C19, such as citalopram, imipramine and diazepam. Trimegestone is an effective and well-tolerated new progestin, which does not negate the beneficial effects of oestrogen on lipids.

Cloprednol is a steroid, which was used for the treatment of asthma. The exact mechanism of cloprednol action is unknown. The drug was marketed under several names, including Syntestan and Cloradryn, however, its current marketing status is unknown and supposed to be discontinued.