m-Chlorophenylpiperazine (meta-chlorophenylpiperazine or mCPP) is a psychoactive substance, which is illegal in many countries but can be found on the black market. It induces endocrine, neurological and psychiatric effects. mCPP is a partial agonist at the 5-HT2C receptor but antagonized the 5-HT2B and 5-HT3 receptors. mCPP is also an active metabolite of the drug trazodone, which is used as an effective antidepressant drug with a broad therapeutic spectrum, including anxiolytic efficacy. It is known, that mCPP induces migraine attacks and that the decrease of food intake induced by the mCPP depends on its ability to act as a serotonin agonist is a brain.

Toreforant (JNJ-38518168) is an orally active, selective histamine H4 receptor antagonist. Toreforant was investigated as an agent for the treatment of active rheumatoid arthritis. While some improvement in rheumatoid arthritis signs/symptoms through week 12 was observed in the phase IIa study, no efficacy was observed with toreforant at lower doses in a subsequent phase IIb study. Toreforant has been tested in clinical studies in patients with asthma and psoriasis. Toreforant failed to provide therapeutic benefit in population of patients with uncontrolled, eosinophilic, persistent asthma. Toreforant efficacy at 30 and 60 mg was greater than placebo but did not meet predefined success criterion in patients with moderate-to-severe psoriasis.

Palonidipine (also known as TC 81) a calcium antagonist that was developed by Teijin for the treatment of hypertension and angina pectoris. Palonidipine was involved in phase II clinical trials in Japan. However, these studies were discontinued.

Nolomirole (CHF1035) is an orally active, selective dopamine agonist, primarily activating DA2- and alpha2 receptors, thereby inhibiting norepinephrine release, which may be beneficial in heart failure. Nolomirole is able to attenuate the heart failure signs in the monocrotaline-induced congestive heart failure. CHF1035 is a mixture of two enantiomers, CHF1800 (+) and CHF1810 (-). CHF1035 and its metabolite CHF1024 significantly decreased the IOP in rabbits, and are potential novel IOP lowering agents. Especially, CHF1035 produced a substantial decrease in IOP for a prolonged period of time, and thus may prove useful in glaucoma therapy. Nolomirole is a pre-synaptic stimulator of DA2-dopaminergic and α2-adrenergic receptors in peripheral sympathetic nerve endings. These receptors act as a negative feedback mechanism, inhibiting norepinephrine secretion. In early phase clinical studies lasting 1–3 months, nolomirole reduced peripheral systemic resistance and 24 hour blood pressure and increased cardiac output. In a study of 29 patients with heart failure, followed for 10 days, a reduction in plasma norepinephrine was demonstrated. In spite of the fact that Nolomirole was in clinical trials for the treatment of heart failure, its development was discontinued.

Cyacetacide is a biochemical used in the past as an anti-tuberculosis agent and currently used in Russia to for the treatment of various forms of tubercular lesions of the eye: keratitis, scleritis, uveitis, chorioretinitis, tuberculosis-allergic diseases and eye diseases of non-tubercular origin. Cyacetacide has also been used to derive compounds that may have antitumor properties.

Pfizer developed fosdagrocorat (PF-04171327), a dissociated agonist of the glucocorticoid receptor for the treatment of rheumatoid arthritis. The drug successfully completed the phase II clinical trial; however, further study of the drug was discontinued.

Eticlopride {2S(−)-3-chloro-5-ethyl-N-[(1-ethyl-2-pyrrolidinyl)methyl]-6-hydroxy-2-methoxybenzamide} is an antagonist at dopamine D2 and D3 receptors. It is widely used for in vivo, in vitro, and ex vivo examination of D2/D3 receptors densities and function. Eticlopride exerts antipsychotic activity in animals.

Betaprodine is an opioid analgesic under international control according to the UN Single Convention 1961. It has been used in obstetrics, as pre-operative medication, for minor surgical procedures.