Cyprenorphine is a mixed agonist-antagonist of opioid receptors. In clinical trials, administration of cyprenorphine induced psychotomimetic effects in pre-operative patients.

Cycloheximide is an antibiotic produced by fermentation culture of Streptomyces griseus, Streptomyces noursei, Streptomyces albulus, Streptomyces naraensis, or other cycloheximide-producing microorganism. It was first discovered by A. Whiffen et al. in 1946. She observed the activity of the compound against the yeasts and it became known as the first antifungal antibiotic. Cycloheximide has been marketed as a plant fungicide for many years and this use continues mainly against fungal diseases of turf and for powdery mildew on roses. More recently, cycloheximide has been recognized and is being developed as an abscission agent for citrus fruits and olives. Due to significant toxic side effects, including DNA damage, teratogenesis, and other reproductive effects, cycloheximide is generally used only in in vitro research applications, and is not suitable for human use as a therapeutic compound. Cycloheximide is an antimitotic and an inhibitor of the synthesis of both DNA and protein.

Cloticasone propionate is an ester of an antiinflammation steroid cloticasone.

The synthetic steroid nivazol lacks three of the substituents considered to be important for glucocorticoid activity, i.e. the 3-keto, the 11-hydroxy, and the 20-keto groups. Nevertheless, in the rat, nivazol has the activity profile of a glucocorticoid. Nivazol elicits numerous glucocorticoid activities in the rodent, but only the inhibition of the hypothalamic-pituitary-adrenal axis was observed in the primate. Nivazol has been investigated with respect to the treatment of Cushing's disease. In a patient with Nelson's syndrome nivazol was clearly highly effective in decreasing plasma ACTH concentrations and pigmentation. Its mechanism of action is similar to that of hydrocortisone. Both steroids directly inhibit in vitro ACTH secretion from corticotroph tumour cells removed from patients with Nelson's syndrome and block stimulation of ACTH release by ovine corticotrophin releasing factor and arginine vasopressin.

Epostane (WIN-32729) a pure competitive inhibitor of 3-beta-hydroxysteroid dehydrogenase. Epostane blocks progesterone synthesis during the luteal phase and in pregnancy in women and has strong anti-steroidogenic effect in endocrine tissues. Epostane is an abortifacient agent in early human pregnancy. It inhibits ovarian follicular steroidogenesis and ovulation.

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.

Dexoxadrol is a sigma receptor agonist. Dexoxadrol, the D-isomer of dioxodrol, which produces PCP-like behavioural effects and displaces bound [3H]PCP, was a potent blocker of the PCP-sensitive, voltage-gated K+ channel. Dexoxadrol was developed as analgesics for use in humans, however, severe side effects including psychotomimetic effects, unpleasant dreams and aberrations stopped the clinical evaluation of dexoxadrol. Dexoxadrol is a NMDA receptor antagonist, which possesses high affinity to the phencyclidine binding site within the NMDA receptor associated ion channel.

Descinolone acetonide (an analog of triamcinolone acetonide) is a glucocorticoid which was developed for the treatment of skin disorders. It was tested on patients with psoriasis and atopic dermatitis, however there is no information about its further development.

11-Deoxycortisol (also known as cortodoxone) is the predominant deoxycorticosteroid and is the immediate precursor of cortisol, which is formed by the enzymatic action of 11beta-hydrozylase (P450). Deficiency of this enzyme causes congenital adrenal hyperplasia, which is characterized by hypertension. 11-deoxycortisol is measured as part of the Metyrapone Test. Metyrapone blocks the formation of cortisol, resulting in increased secretion of Adrenocorticotropic hormone (ACTH) and 11-deoxycortisol in normal individuals.