Trestolone is a synthetic androgen that inhibits the release of follicle-stimulating hormone and impairs spermatogenesis. Luteinizing hormone is also suppressed, which cuts production of testosterone. The azoospermia and oligospermia are reversible after discontinuation of trestolone. Trestolone has androgenic and anabolic properties and loss of secondary sex characteristics is not seen. Like testosterone, trestolone undergoes enzymatic aromatization to an estrogen. The use of trestolone instead of testosterone for androgen replacement therapy could have health-promoting effects by reducing the occurrence of prostate disease. Trestolone had been in phase II clinical trial for the andropause control. However, this development was discontinued.

Clostebol is a synthetic anabolic-androgenic steroid, a derivative of the natural hormone testosterone. Clostebol is a Schedule III controlled substance used medically in topical ophthalmologic and dermatologic treatments. Due to potential use as a performance-enhancing drug, clostebol is banned by the World Anti-Doping Agency.

Orbofiban was developed as an orally active glycoprotein IIb/IIIa antagonist. By 2001, this drug had progressed to phase III clinical trials. Unfortunately, was found that orbofiban induced thrombocytopenia and thrombosis. In addition, despite no significant excess risk of intracranial hemorrhage, orbofiban was not effective in preventing ischemic stroke or transient ischemic attack. Besides, the use of this drug had led to an increase in mortality. Based on all these results further development of this drug was discontinued.

Pexiganan is a 22-amino-acid synthetic cationic peptide. It is an analog of magainin 2, which is a host defense peptide isolated from frog skin. The drug is thought to act by disturbing the permeability of the cell membrane or cell wall. Pexiganan exhibited in vitro broad-spectrum antibacterial activity when it was tested against 3,109 clinical isolates of gram-positive and gram-negative, anaerobic and aerobic bacteria. It is currently in phase 3 clinical trials as a topical antimicrobial agent for the treatment of mild infections associated with diabetic foot ulcers. In vitro data for pexiganan acetate suggest that the drug does have hemolytic activity at concentrations relevant for antibacterial activity. In association with tigecycline, pexiganan administration could overcome antibiotic resistance and increase the effectiveness of treatment against P. aeruginosa sepsis.

Prazarelix is gonadorelin (GnRH) antagonist. It is primarily used in assisted reproduction to control ovulation. The drug works by blocking the action of GnRH upon the pituitary, thus rapidly suppressing the production and action of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).