GP Cheque Drops is a product containing the hormone Mibolerone. Mibolerone an oral steroid which is a derivative of the hormone nandrolone placed into a 7, 17 dimethylated state. This makes mibolerone far more potent than the parent hormone it is derived from. Mibolerone was developed in 1963 and first marketed by the pharmaceutical company UpJohn under the name Cheque Drops as a vetnary medication. The original use of the drug was for it to be administered to female dogs to prevent them from going into heat, although veterinarians often took caution before prescribing this medication to dogs for extended periods of time due to side effects in the animals which may include clitoral enlargement, aggression, liver damage, and urinary tract problems.

Cheque Drops earned the reputation in the bodybuilding community as one of the strongest steroids ever made. Users often reported a rapid increase in strength and muscle mass and also increased aggression in the gym. The aggression caused by Cheque Drops often led the idea that it was used by some fighters and powerlifters before competing in their respective sports. Mibolerone also displays strong estrogenic characteristics and will raise the levels of estrogen in the body dramatically during use. Because of this, estrogen related side effects such as water retention, excess body fat, and gynecomastia are always a concern when using this product. Because of this, users of this product will often want to include an anti-estrogen such as arimidex or aromasin during use of this drug. It is also important to note that mibolerone displays strong progestin activity in the body. High progesterone levels can cause side effects similar to those seen from elevated estrogen levels. To help combat this, users might also consider running an agent such as cabaser or bromocripten during administration of Cheque Drops.

Although it was never approved for use in humans, mibolerone still found its way into the bodybuilding community. Typcially, males would use a dosage of 200-500mcg a day preferably on an empty stomach to increase bioavailability. Cycles should be limited to a maximum of 8 weeks due to the toxic nature of this compound.