Primobolan

Primobolan is the trade name for the anabolic steroid Methenolone (also written as Metenolone). It is available in both an injectable oil-based format, as well as an oral form. Injectable Primobolan is known as Methenolone Enanthate, and the oral format is known as Methenolone Acetate. It is a very well-known and popular anabolic steroid due to its very mild nature as both an anabolic and an androgenic compound. It is often compared to Anavar, a similar anabolic steroid but the difference between the two is very distinct – Anavar possesses a far greater anabolic strength rating than Primo. Primobolan is actually a very weak anabolic steroid, weaker in fact, than Testosterone itself. It possesses an anabolic rating of 88, while Testosterone’s anabolic strength rating is 100 – this demonstrates Primobolan’s fairly weak strength in terms of anabolic capabilities. The same holds true for its androgenic strength rating, which is approximately 44 – 57 in comparison with Testosterone’s androgenic rating of 100. This weaker androgenic strength rating is actually very favorable, but its weak anabolic strength capability leaves it as a far less desired anabolic steroid where the majority of individuals considering its use often opt for Anavar instead. It is instead utilized as primarily a compound in cutting cycles, whereby the preservation of muscle mass is the goal instead of the addition of new mass. Along this same line of logic, this anabolic is almost never utilized in bulking cycles due to its lack in anabolic strength.

Primobolan’s properties and details were first released and published in 1960[1]. Squibb released the injectable format of Primobolan (Methenolone Enanthate) first in 1962 followed by the release of the oral variant of Primo (Methenolone Acetate) into the American market in the same year[2]. It was at the time marketed under the brand name Nibal Depot (for the injectable) and Nibal for the oral variant dosed at 20mg per tablet. Very shortly afterwards, the rights for manufacture of the compound were sold in West Germany to Schering. Following this sale of rights, Nibal was removed from the US market and instead, Schering marketed the compound under the new trade name Primobolan (for both variants). It then became the quintessential anabolic steroid manufactured by Schering, who then marketed the compound as an internationally exclusive drug, and would never return to the American Market. An interesting point to note is that even though Primobolan was never marketed in the United States after Schering had bought the rights to it, it is still listed as an FDA approved drug. This had enabled American doctors to be able to import it on special order.

Within the medical field, Methenolone is utilized to treat individuals suffering from conditions in which muscle wasting and severe weight loss is a symptom. Other uses include: an immunostimulant for individuals fighting infections, wasting conditions, an adjunct to countering the effects of prolonged corticosteroid therapy, and the treatment of osteoporosis as well as sarcopenia (the loss of muscle as correlated with aging). Primo, like Anavar, as proven to be so mild in its negative effects that it has also been utilized in children as well as infants in order to promote weight gain in premature born infants without any indications of ill effects or toxicity[3]. One can easily see where the allure of this anabolic steroid comes from within the athletic and bodybuilding community, as it is a compound that exhibits weak androgenic effects with very little to no side effects.

Like most anabolic steroids at the time, in the early 1990s it was eventually pulled from all markets and Schering ceased production as a result of the increasingly growing mass hysteria surrounding anabolic steroids and the growing anti-steroid sentiment in the media of the time. As a result, pharmaceutical Primobolan manufactured by Schering is today only sold in a small select number of countries across the world, such as Spain Turkey, Japan, Paraguay, and Ecuador.

As far as the oral variant is concerned (Methenolone Acetate), it too was pulled from the majority of markets and ceased production as well. However, pharmaceutical grade oral Primo can be located in Japan and South Africa. In general, pharmaceutical grade oral Primobolan products are even more rare than the injectable, and only small amounts of 5mg and 25mg tablets from Schering may still be located on the market in extremely rare and small amounts.

Common Name(s): Primobolan, Primo, Methenolone, Rimobolan
Chemical Name: Methenolone Acetate (oral) or Methenolone Enanthate (injectable)
Class/Category: Anabolic-Androgenic Steroid (AAS)

Primobolan, fondly known as Primo, is a mild anabolic steroid celebrated for its low androgenic effects and ability to preserve muscle mass during cutting phases or calorie deficits. It’s a favorite among those looking for lean, steady gains without excessive water retention, making it ideal for cutting or lean-bulking cycles. While not a dramatic mass builder, Primo’s results are high-quality and sustainable when paired with proper training and diet.

Primo’s Enanthate ester requires weekly or bi-weekly injections, while Acetate (oral) demands daily dosing. Start with a conservative approach to assess tolerance.