Methenolone Enanthate (also known as primobolan) was described in 1960. Squibb Company began producing injectable drug in 1962. Methenolone originally was prescribed in case of muscle loss after operations, infections, long-term illnesses, aggressive therapy with corticoids or malnutrition, and in some cases it was used to treat osteoporosis and breast cancer. Methenolone was commonly used to promote weight gain in infants, weighing less than normal, without any side effects.

Methenolone is an anabolic steroid, modification of dihydrotestosterone (DHT) with weak androgenic activity and a moderate anabolic effect. A notable trait of methenolone is that it can firmly bind to androgen receptors, stronger than testosterone.

The Methenolone hormone has also been shown to have a positive effect on the immune system. In cases of muscle wasting and immune issues such as with AIDS, Primobolan has proven very useful. It may very well not be the only steroid used in such cases. As it won’t promote strong mass characteristics it probably won’t be the only one prescribed. However, the moderate anabolic nature along with immune enhancement makes it a top choice in these cases.