"Harms surrounding AAS [Anabolic-Androgenic Steroids] are mostly discussed in general terms, while specific differences between compounds are seldom discussed. Underwood [7] posits that there is a need, particularly regarding trenbolone, to discuss individual compounds. Trenbolone is an AAS, derived from the nandrolone group but differing from nandrolone by an addition of a double bond between C10-C9 and C11-12 [8]. Although originally used by veterinarians on livestock to increase muscle growth and appetite [9], injectable trenbolone was originally adapted for use by bodybuilders from the dissolution of Finaplix H pellets [10] who refer to the compound as ‘tren’. Trenbolone was not originally designed for oral routes of administration [9]. Further, the liver readily metabolises natural AASs except when that AAS has been modified to pass through the liver without destruction, known as 17-alkylated AAS [11] of which trenbolone is not one, and therefore is commonly injected by users [7, 12]. Trenbolone possesses strong anabolic properties and nutrient partitioning effects, boosts the mineral absorption and improves lean muscle mass [9] and, therefore, is often used to enhance the strength gains and protein synthesis which comes from strength training [13]. It has also been found to have the secondary effects of stimulating appetite, reducing fat deposition and decreasing the rate of catabolism [14]. Trenbolone likely represents an attractive option to AAS users given it has been found to be significantly more potent than testosterone [14]. Specifically, trenbolone has a binding affinity for the androgen receptor three times as high as testosterone [14]. Trenbolone is available in a number of preparations: the shortest esterified version available is trenbolone acetate, with a half-life of 1–2 days; trenbolone hexhydrobenzylcarbonate, which has a half-life of approximately 8 days; and trenbolone enanthate, which has a half-life of 11 days [15]. Trenbolone and nandrolone are considered to be closely linked given they are both 19-Nor AAS [1, 16].

"Treatment with 19-Nor AAS—nandrolone group—can cause significant alterations in the density of serotoninergic receptors in animals [17] leading to an established AAS-serotonin link which is believed to underpin why AAS are associated with changes in emotional states and behaviour [18]. Trenbolone, specifically, has been linked with not only cardiovascular issues [10] but also with extreme instances of violence [12]. Short term side effects of trenbolone which have been identified include insomnia, high blood pressure and increased aggression and libido [14]. Research has suggested these instances of psychological and emotional instability are attributable to modulated serotonin receptor activity and associated with decreased serotonin neurotransmission [16]. Indeed, nandrolone and trenbolone (the two 19-Nors) [19] have been identified as the most neurotoxic of AAS [16] and, therefore, warrant further exploration in the risk profile for psychological harm to users."


Piatkowski TM, Neumann DL, Dunn M. 'My mind pretty much went to mush': A qualitative exploration of trenbolone in the performance and image enhancing drug community. Drug Alcohol Rev. 2023;42(6):1566-1576. doi:10.1111/dar.13656