Methenolone is a brand name for metenolone — the “h” is omitted in the latter — an anabolic steroid best known for its effects on the regulation of human male characteristics through androgen receptor binding. Its most common derivative is methenolone enanthate, or metenolone enanthate. Other brand names for the drug include Primbolan and Nibal, and it is sold in tablet or injection form.
The pharmaceutical category to which methenolone belongs is anabolic steroids. These drugs are used to induce tissue growth by producing more protein. This process is known as anabolism, and the tissue enhancement leads to bulkier muscles.
This steroid also imitates male sex hormones such as testosterone and dihydrotestosterone (DHT). Both are examples of androgenic hormones, which are responsible for developing and maintaining masculine characteristics such as the reproductive organ, facial hair and vocal chords. Thus, methenolone is officially known as an anabolic-androgen steroid (AAS). Some athletes use methenolone for building up muscle mass and physical power.
Methenolone enanthate in particular is designed to mimic dihydrotestosterone, which is the active form of testosterone. Known as the most active androgen, or male sex hormone, DHT activates androgen receptors much faster than testosterone; this action is necessary for the development of the male characteristics. Methenolone enanthate is called Primobolan in tablet form and Primobolan Depot in intramuscular injection form. The injected form is preferred over the tablet due to its comparatively lower cost.
With an increase in DHT, men have a greater possibility of developing male pattern baldness and prostate cancer. Methenolone use by women can lead to the development of male secondary sex characteristics, making them more androgynous with traits such as deepened vocal chords, facial hair and shrunken breasts. The use of this steroid could have additional adverse health consequences for both genders; for example, increased DHT could lead to the risk of hyperplasia, or an increased number of cells.
In U.S. popular culture, methenolone is well known for its role in steroid scandals that affected the Major League Baseball (MLB) organization in the 2000s. Barry Bonds, an accomplished outfielder who played for about two decades in the MLB, allegedly tested positive for Primobolan in 2000 and 2001, although such a claim has never been substantiated. It was also one of the steroids that another star baseball player, Alex Rodriguez, tested positive for during his two-year stint with the Texas Rangers from 2001 to 2003.