Mibolerone (Cheque Drops) for Pre-Competition Aggression — Anabolic Steroids

Overview

Mibolerone (brand name Cheque Drops, later Cheque Medicated Dog Food) is a potent synthetic androgen developed by Upjohn Company in 1963 as a veterinary drug for the suppression of estrus (heat) in female dogs. It is a 7α,17α-dimethyl-19-nortestosterone derivative that is among the most potent androgens ever synthesized, with an androgenic potency approximately 5.9 times that of testosterone and an anabolic potency approximately 2.4 times that of testosterone. Mibolerone binds with exceptionally high affinity to the androgen receptor (AR), progesterone receptor (PR), and glucocorticoid receptor (GR), creating a unique polypharmacological profile that produces extreme CNS-mediated aggression — a property exploited by powerlifters, strongman competitors, and combat sport athletes who administer the drug sublingually 30-60 minutes before competition. Despite its potency, mibolerone is rarely used for prolonged periods because it is among the most hepatotoxic oral anabolic steroids known, being both 17-alpha-alkylated and a 19-nortestosterone derivative with exceptionally slow hepatic clearance. Even short-term use (2-4 weeks) has been associated with significant liver enzyme elevations and clinical hepatotoxicity. The drug was originally available as Cheque Drops (oral solution) for veterinary use but was voluntarily withdrawn from the US market due to concerns about diversion for human use. It is classified as a Schedule III controlled substance under the Anabolic Steroid Control Act. Mibolerone is NOT approved for human use in any country and has never undergone human clinical trials. Its use in athletics is prohibited by WADA and all major sporting organizations. The extreme hepatotoxicity, combined with its potent estrogenic suppression (via PR agonism) and potential for severe androgenic side effects, makes mibolerone one of the most dangerous performance-enhancing drugs in the AAS pharmacopeia.

Indications

• Veterinary: Estrus suppression in female dogs (original Upjohn indication, withdrawn)
• Misused: Pre-competition aggression enhancement in powerlifting and combat sports
• Misused: Sublingual administration 30-60 minutes before competition for CNS stimulation
• Research: Investigation of multi-receptor (AR/PR/GR) androgen pharmacology
• Never approved for any human indication

Mechanism of Action

Mibolerone administered sublingually for rapid absorption and CNS effect (onset 15-30 minutes) or orally for systemic exposure. 17-alpha-alkylation provides oral bioavailability but confers extreme hepatotoxicity. Doses measured in micrograms reflecting exceptional potency

Dosing

Safety & Contraindications

• EXTREME hepatotoxicity — among the most liver-toxic oral AAS known
• 17-alpha-alkylated AND 19-nortestosterone derivative — dual hepatotoxic mechanisms
• Significant liver enzyme elevations even with short-term use (days to weeks)
• 5.9x more androgenic than testosterone — severe androgenic side effects
• Binds PR and GR in addition to AR — complex polypharmacological profile
• Extreme aggression and irritability — psychological safety concern
• Profound HPG axis suppression — complete testosterone shutdown
• Schedule III controlled substance — illegal without prescription
• Veterinary product withdrawn from US market due to diversion concerns
• NEVER use for more than 2 weeks — severe hepatotoxicity risk
• WADA prohibited substance
• Not designed for human physiology — no human PK or safety data