Eprotirome (KB2115) is a thyroid hormone mimetic developed at Karo Bio AB (Huddinge, Sweden). Eprotirome has a 22-fold higher affinity for thyroid hormone receptor (TR)β in comparison with TRα. It lowers plasma LDL cholesterol and stimulates bile acid synthesis. Eprotirome can lower LDL cholesterol concentrations in patients with familial hypercholesterolaemia when added to conventional statin treatment with or without ezetimibe, but that it has the potential to induce liver injury. These findings, along with findings of cartilage damage in dogs, raise serious doubts about selective thyroid hormone mimetics as a therapeutic approach to lower LDL cholesterol concentrations. Eprotirome development was discontinued.

Psilocybin is a naturally occurring psychedelic prodrug compound produced by more than 200 species of mushrooms, collectively known as psilocybin mushrooms. Once ingested, psilocybin is rapidly metabolized to the psilocin, which then acts on serotonin receptors in the brain. Psilocybin was identified as the active hallucinogenic compound in magic mushrooms in 1959, but humans have used assorted psilocybin mushrooms in religious ceremonies since prehistoric times. In the 1960's psilocybin was marketed for use as a treatment for various psychoses, however, it was withdrawn from the market when the regulatory environment changed. Recently there has been as renewed interest in studying the medicinal uses of psilocybin for treatment of anxiety, depression, migraine headaches, addictions, and other neuropsychiatric conditions.

N,N-Dimethyl-5-Methoxytryptamine (aka 5-MeO-DMT) is a psychedelic of the tryptamine class. It is found in a wide variety of plant species, and a single psychoactive toad species, the Colorado River toad. Like its close relatives DMT and bufotenin (5-HO-DMT), it has been used as an entheogen in South America. It can also be found in the dart poison traditionally used by the Yanoama Indians of Upper Orinoco. It acts as a non-selective serotonin (5-HT) agonist. -MeO-DMT is O-demethylated by polymorphic cytochrome P450 2D6 (CYP2D6) to an active metabolite, bufotenine. 5-MeO-DMT is classified as a controlled substance in China, Australia, Sweden, Turkey, and the USA.

16,16-dimethyl Prostaglandin E2 acts as an agonist on most prostaglandin E (EP) receptor subtypes, it has prolonged half-life in vivo, because it is not a substrate for the enzyme 15-hydroxy prostaglandin dehydrogenase. This compound was studied by Fate Therapeutics in phase I clinical trials under the name FT1050 or ProHema-CB for pediatric patients with hematologic malignancies. However, this study was terminated.

Quizapine is a piperazine-based nonselective serotonin (5-HT) receptor agonist with antidepressant and oxytocic activities. Quipazine targets and binds to serotonin receptors, particularly to the 5HT2A and 5HT3 receptors. Quipazine is a potential anti-parkinsonian agent. Serotonin receptor activation by quipazine may lead to smooth muscle contraction and antidepressant effects. quipazine, a central serotonergic agent, counteracted some of the drug-induced symptoms of pseudoparkinsonism in laboratory animals. Cholinergic, dopaminergic and histaminergic receptors play an important role in the manifestations of these symptoms.

Muscimol is one of the principal psychoactive constituents of Amanita muscaria and related species of mushroom. Muscimol is a potent, selective agonist for the GABAAreceptors and displays sedative-hypnotic, depressant and hallucinogenic psychoactivity. The effects of the Amanita mushrooms begin 30–120 minutes after consumption and the effects last for 5–10 hours. Some of the desired effects include euphoria, dream-like (lucid) state of mind, out-of-body experiences, and synesthesia. Neutral effects include dizziness, clumsiness, the feeling of increased physical strength, loss of equilibrium, and a glassy-eyed stare. Calming effects may be felt, but completely opposite effects such as extreme energy bursts have been described. Negative effects include mild to moderate nausea, stomach discomfort, increased salivation, and muscle twitching or tremors. In large doses, strong dissociation or delirium may be felt.

Fenretinide (4-HPR) is an orally-active synthetic phenylretinamide analogue of retinol (vitamin A) with potential antineoplastic and chemopreventive activities. Fenretinide binds to and activates retinoic acid receptors (RARs), thereby inducing cell differentiation and apoptosis in some tumor cell types. This agent also inhibits tumor growth by modulating angiogenesis-associated growth factors and their receptors and exhibits retinoid receptor-independent apoptotic properties. Phase III clinical trial data has suggested that fenretinide reduces breast cancer relapse in pre-menopausal women. Fenretinide is the most studied retinoid in breast cancer chemoprevention clinical trials due to its selective accumulation in breast tissue and its favorable toxicological profile. This agent showed a significative reduction of the incidence of second breast tumors in premenopausal women confirmed after 15-year followups. Fenretinide, a drug being developed by Sirion Therapeutics, slowed the progression of advanced dry age-related macular degeneration (AMD) by 45 percent for people receiving a higher dose of the treatment in a Phase II clinical trial. Sirion has been granted a Fast Track designation for the treatment by the FDA. Fenretinide is in phase II clinical trials for the treatment of B-cell lymphoma, chronic lymphocytic leukemia. It is also in phase I clinical trials for the treatment of cystic fibrosis.

Zearalenone (ZEN) is a toxic non-steroidal mycoestrogen produced by fungi that widely contaminate agricultural products, eliciting estrogenic responses by mimicking sex steroid hormones. Zearalenone is biosynthesised through a polyketide pathway by a variety of Fusarium fungi including Fusarium graminearum (Gibberella zeae), Fusarium culmorum, Fusarium equiseti, Fusarium crookwellense, Fusarium cerealis and Fusarium semitectum. Zearalenone and its derivatives share similar molecular mechanisms and activity with estrogens. They interact with the estrogen receptors (ERa and ERb) leading to functional and morphological changes in the reproductive system in both animals and humans. Zearalenone exposure is associated with the estrogenic syndrome and infertility in animals and premature thelarche and precocious puberty in girls. In animal models, it was found that prepubertal exposure to a low dose of Zearalenone, decreased breast cancer risk. When prepubertal rats were treated with 20 lg (1 mg ⁄ kg body weight) of Zearalenone, a significant reduction of both the incidence and multiplicity of DMBA-induced mammary tumours was noted. Zearalenone has been used to treat postmenopausal symptoms in women.

Oxotremorine, a metabolite of tremorine, is a non-hydrolyzed muscarinic acetylcholine receptor agonist used as a research tool. This compound is a muscarinic agent equal in potency to acetylcholine, but completely lacking in nicotinic activity.