drtbear1967
Musclechemistry Board Certified Member
Primobolan (Methenolone)
Overview and History of 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.
Chemical Characteristics of Primobolan
Primobolan is a Dihydrostestosterone (DHT) derivative, landing it in the family of DHT-derivatives and analogues. Primo is a modified form of DHT, where it contains a double-bond between carbon atoms 1 and 2 in the Dihydrotestosterone structure. This is known to assist in the stabilization of the 3-keto group which in turn increases the anabolic strength of the hormone. A 1-methyl group is also added to the hormone, which is responsible for allowing the hormone to resist hepatic (liver) metabolism and breakdown.
The oral format of Primobolan holds an Acetate ester chemically bonded to it, which is attached to the 17-beta-hydroxyl group on the chemical structure. This allows the oral anabolic steroid to be resistant to oxidation and hepatic breakdown through oral administration. The oral form of Primobolan has demonstrated effective oral bioavailability in studies as both in its Acetate format as well as its un-esterified format[4] [5]. Esterification will now be explained in more detail.
The injectable format (Methenolone Enanthate) in particular is simply Methenolone with the Enanthate ester bound to the Methenolone chemical structure. Specifically, ‘Enanthate’ is Enanthoic acid (also known as carboxylic acid), but once bound to Methenolone it is properly referred to in chemistry as an ester bond (or ester linkage). Enanthoic acid is chemically bonded to the 17-beta hydroxyl group on the Methenolone structure. The addition of this ester augments the hormone’s release rate and half-life to favor a longer window of release. The primary reason for the augmentation of its half-life and release rate is because once Methenolone Enanthate enters the bloodstream, enzymes work to break the bond between the ester and the hormone, which takes a varying amount of time. The end result is that of the ester being removed from the hormone by these enzymes, and the result after this is pure Methenolone that is free to do its work in the body. This process of enzymes removing the ester from the hormone to which it is attached is what is responsible for the slower release rates. When the Enanthate ester is attached to Methenolone, creating Methenolone Enanthate, the half-life of Primobolan is now extended to 10 days, providing a slower release and activity of the hormone.
Properties of Primobolan
Primobolan being a DHT-derivative, it holds many of the same properties of its parent hormone. For example its not aromatized by the aromatase enzyme into Estrogen at any dose[6]. Therefore, any individual looking to utilize it should never experience any Estrogen related side effects from using it alone. This means that it completely avoids the potential for any of the following side effects: water retention and bloating, elevated blood pressure (as a result of water retention), possible fat gain/retention, and gynecomastia. Without the puffy and soft look that aromatizable anabolic steroids provide the physique, Primobolan is regarded by the majority of bodybuilders and athletes as a preferred ‘cutting’ compound considered very useful for pre-contest cycles and fat loss and cutting phases.
Unfortunately, because of its poor anabolic strength rating making it lower in strength than Testosterone, Primobolan is not preferred by athletes or bodybuilders for bulking cycles, lean mass cycles, or for any measurable strength gain. Primo is also best combined with (stacked with) other anabolic steroids as well, whether utilizing it for a cutting cycle or a bulking or lean mass cycle. The use of Primobolan solitarily on its own is regarded by many as a near useless practice, and along these same lines, many anabolic steroid users claim that Primo is only useful at very high doses, which may not be very practical considering the high cost of this anabolic steroid. This dosing information will be further expanded in the doses section of this profile.
Primobolan Side Effects
The first thing to understand with Primobolan is that it is a DHT-derivative, meaning it is a modified form of DHT (Dihydrotestosterone). As such, it carries with it many similar properties and characteristics, including the inability to convert (aromatize) into Estrogen at any dose used[6]. This should certainly be a comforting fact to most individuals who are concerned about Estrogenic side effects, such as bloating, gynecomastia, high blood pressure as a result of water retention, etc.
Although the oral format of Primobolan is C-17 Alpha Alkylated (also known as Methylation), which is a process that tends to make oral compounds present a degree of harm to the liver, Primobolan has never shown any measurable hepatotoxic effects to the body[7]. Although oral Primo does not impose any measurable negative effects on the liver, it still presents some small amount of hepatotoxicity and this should still be understood, especially when it comes to extended cycle lengths and/or very high dosages. With that being said, one death of an anemic patient who was prescribed oral Primobolan has been linked to its use[8]. Once again, high doses and/or very long cycle lengths of oral Primobolan may be a concern.
As much as Primobolan is touted by athletes and bodybuilders as being a ‘mild’ anabolic steroid, it still exhibits suppression of endogenous Testosterone production and HPTA function. In fact, studies have confirmed that at even a very low dosage (30 – 45mg daily), test subjects experienced 15 – 65% suppression of natural endogenous Testosterone production[9]. Being that those dosages as far lower than what is required for performance enhancement purposes, it is still heavily recommended to perform a proper PCT (Post Cycle Therapy) following the discontinuation of Primobolan.
Primobolan Cycles and Use
Primobolan cycles are commonly in the form of fat loss and/or cutting cycles. It is almost never used as a bulking or mass-gaining agent, and most of its use is in the form of a pre-contest drug in the final weeks leading up to a competition show or photo shoot. It is typically cycled with other compounds that hold similar qualities, properties, and half-lives. Many bodybuilders often stack Primobolan with Testosterone Propionate (or Testosterone Enanthate) and use it for the first 8 weeks of a cycle in order to assist in the retention of muscle mass during periods of low caloric intake.
Other bodybuilders will perform oral Primobolan cycles stacked with compounds such as Testosterone Propionate and Trenbolone Acetate, as all of the compounds involved work synergistically especially where half-lived are concerned. Some may opt to use Primobolan (either the oral or injectable) with some form of Testosterone and Winstrol (Stanozolol), typically the injectable form if it is with the oral Primobolan. It is important to remember not to utilized two different oral compounds within the same cycle.
Oral Primobolan (Methenolone Acetate) should normally be run for no longer than 8 weeks, and the injectable form (Methenolone Enanthate) can be run in cycle lengths of 10 – 12 weeks (or longer, depending on the individual’s goals and desires).
Primobolan Dosages and Administration
Primobolan dosage and administration depends heavily upon which form is being used: oral or injectable. Medical prescription Primobolan dosages outline 200mg as a first dosage, followed with 100mg every week for the complete duration of therapy. The medical condition being treated would determine what the actual full Primobolan dosage is. The range can be anywhere from 100mg every one or two weeks to 200mg every two to three weeks. Medical guidelines for oral Primobolan dosages call for 100 – 150mg per day for no longer than 6 – 8 weeks of consistent use.
Where bodybuilding, athletics, and performance enhancement is concerned, beginner Primobolan dosages for the injectable format normally start at about 400mg per week. Intermediate Primobolan dosages are usually in the range of 400 – 700mg per week, which should be adequate enough, and advanced users may venture as high as 800 – 1,000mg per week. Female Primobolan dosages in terms of safety and minimal virilization are usually in the range of 50 – 100mg per week. Injectable Primo tends to be used far less frequently by females than the oral variant, which is the preferred form.
Oral Primobolan dosages begin in the range of 50 – 100mg per day for beginners, 100 – 150mg per day for intermediates, and 150 – 200mg for advanced users. Female oral Primobolan dosages are usually recommended to be within the range of 50 – 70mg per day, and should present little risk of virilization.
Oral Primo should be administered once per day with no requirement to split up dosages throughout the day, as its half-life is about 2 – 3 days. Injectable Primobolan exhibits a half-life of 7 – 10 days due to the Enanthate ester, and should be administered twice per week, with each injection spaced evenly apart, in order to maintain stable and steady blood plasma levels.
Primobolan Information:
Primobolan (Methenolone)
Chemical Name: 17beta-Hydroxy-1-methyl-5alpha-androst-1-en-3-one, 1-methyl-1(5-alpha)-androsten-3-one-17b-ol
Molecular Weight: 414.621 g/mol
Formula: C27H42O3
Original Manufacturer: Squibb
Half Life: 10 days (Enanthate), 2 – 3 days (oral)
Detection Time: 4 – 5 weeks
Anabolic Rating: 88
Androgenic Rating: 44 – 57
References:
Overview and History of 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.
Chemical Characteristics of Primobolan
Primobolan is a Dihydrostestosterone (DHT) derivative, landing it in the family of DHT-derivatives and analogues. Primo is a modified form of DHT, where it contains a double-bond between carbon atoms 1 and 2 in the Dihydrotestosterone structure. This is known to assist in the stabilization of the 3-keto group which in turn increases the anabolic strength of the hormone. A 1-methyl group is also added to the hormone, which is responsible for allowing the hormone to resist hepatic (liver) metabolism and breakdown.
The oral format of Primobolan holds an Acetate ester chemically bonded to it, which is attached to the 17-beta-hydroxyl group on the chemical structure. This allows the oral anabolic steroid to be resistant to oxidation and hepatic breakdown through oral administration. The oral form of Primobolan has demonstrated effective oral bioavailability in studies as both in its Acetate format as well as its un-esterified format[4] [5]. Esterification will now be explained in more detail.
The injectable format (Methenolone Enanthate) in particular is simply Methenolone with the Enanthate ester bound to the Methenolone chemical structure. Specifically, ‘Enanthate’ is Enanthoic acid (also known as carboxylic acid), but once bound to Methenolone it is properly referred to in chemistry as an ester bond (or ester linkage). Enanthoic acid is chemically bonded to the 17-beta hydroxyl group on the Methenolone structure. The addition of this ester augments the hormone’s release rate and half-life to favor a longer window of release. The primary reason for the augmentation of its half-life and release rate is because once Methenolone Enanthate enters the bloodstream, enzymes work to break the bond between the ester and the hormone, which takes a varying amount of time. The end result is that of the ester being removed from the hormone by these enzymes, and the result after this is pure Methenolone that is free to do its work in the body. This process of enzymes removing the ester from the hormone to which it is attached is what is responsible for the slower release rates. When the Enanthate ester is attached to Methenolone, creating Methenolone Enanthate, the half-life of Primobolan is now extended to 10 days, providing a slower release and activity of the hormone.
Properties of Primobolan
Primobolan being a DHT-derivative, it holds many of the same properties of its parent hormone. For example its not aromatized by the aromatase enzyme into Estrogen at any dose[6]. Therefore, any individual looking to utilize it should never experience any Estrogen related side effects from using it alone. This means that it completely avoids the potential for any of the following side effects: water retention and bloating, elevated blood pressure (as a result of water retention), possible fat gain/retention, and gynecomastia. Without the puffy and soft look that aromatizable anabolic steroids provide the physique, Primobolan is regarded by the majority of bodybuilders and athletes as a preferred ‘cutting’ compound considered very useful for pre-contest cycles and fat loss and cutting phases.
Unfortunately, because of its poor anabolic strength rating making it lower in strength than Testosterone, Primobolan is not preferred by athletes or bodybuilders for bulking cycles, lean mass cycles, or for any measurable strength gain. Primo is also best combined with (stacked with) other anabolic steroids as well, whether utilizing it for a cutting cycle or a bulking or lean mass cycle. The use of Primobolan solitarily on its own is regarded by many as a near useless practice, and along these same lines, many anabolic steroid users claim that Primo is only useful at very high doses, which may not be very practical considering the high cost of this anabolic steroid. This dosing information will be further expanded in the doses section of this profile.
Primobolan Side Effects
The first thing to understand with Primobolan is that it is a DHT-derivative, meaning it is a modified form of DHT (Dihydrotestosterone). As such, it carries with it many similar properties and characteristics, including the inability to convert (aromatize) into Estrogen at any dose used[6]. This should certainly be a comforting fact to most individuals who are concerned about Estrogenic side effects, such as bloating, gynecomastia, high blood pressure as a result of water retention, etc.
Although the oral format of Primobolan is C-17 Alpha Alkylated (also known as Methylation), which is a process that tends to make oral compounds present a degree of harm to the liver, Primobolan has never shown any measurable hepatotoxic effects to the body[7]. Although oral Primo does not impose any measurable negative effects on the liver, it still presents some small amount of hepatotoxicity and this should still be understood, especially when it comes to extended cycle lengths and/or very high dosages. With that being said, one death of an anemic patient who was prescribed oral Primobolan has been linked to its use[8]. Once again, high doses and/or very long cycle lengths of oral Primobolan may be a concern.
As much as Primobolan is touted by athletes and bodybuilders as being a ‘mild’ anabolic steroid, it still exhibits suppression of endogenous Testosterone production and HPTA function. In fact, studies have confirmed that at even a very low dosage (30 – 45mg daily), test subjects experienced 15 – 65% suppression of natural endogenous Testosterone production[9]. Being that those dosages as far lower than what is required for performance enhancement purposes, it is still heavily recommended to perform a proper PCT (Post Cycle Therapy) following the discontinuation of Primobolan.
Primobolan Cycles and Use
Primobolan cycles are commonly in the form of fat loss and/or cutting cycles. It is almost never used as a bulking or mass-gaining agent, and most of its use is in the form of a pre-contest drug in the final weeks leading up to a competition show or photo shoot. It is typically cycled with other compounds that hold similar qualities, properties, and half-lives. Many bodybuilders often stack Primobolan with Testosterone Propionate (or Testosterone Enanthate) and use it for the first 8 weeks of a cycle in order to assist in the retention of muscle mass during periods of low caloric intake.
Other bodybuilders will perform oral Primobolan cycles stacked with compounds such as Testosterone Propionate and Trenbolone Acetate, as all of the compounds involved work synergistically especially where half-lived are concerned. Some may opt to use Primobolan (either the oral or injectable) with some form of Testosterone and Winstrol (Stanozolol), typically the injectable form if it is with the oral Primobolan. It is important to remember not to utilized two different oral compounds within the same cycle.
Oral Primobolan (Methenolone Acetate) should normally be run for no longer than 8 weeks, and the injectable form (Methenolone Enanthate) can be run in cycle lengths of 10 – 12 weeks (or longer, depending on the individual’s goals and desires).
Primobolan Dosages and Administration
Primobolan dosage and administration depends heavily upon which form is being used: oral or injectable. Medical prescription Primobolan dosages outline 200mg as a first dosage, followed with 100mg every week for the complete duration of therapy. The medical condition being treated would determine what the actual full Primobolan dosage is. The range can be anywhere from 100mg every one or two weeks to 200mg every two to three weeks. Medical guidelines for oral Primobolan dosages call for 100 – 150mg per day for no longer than 6 – 8 weeks of consistent use.
Where bodybuilding, athletics, and performance enhancement is concerned, beginner Primobolan dosages for the injectable format normally start at about 400mg per week. Intermediate Primobolan dosages are usually in the range of 400 – 700mg per week, which should be adequate enough, and advanced users may venture as high as 800 – 1,000mg per week. Female Primobolan dosages in terms of safety and minimal virilization are usually in the range of 50 – 100mg per week. Injectable Primo tends to be used far less frequently by females than the oral variant, which is the preferred form.
Oral Primobolan dosages begin in the range of 50 – 100mg per day for beginners, 100 – 150mg per day for intermediates, and 150 – 200mg for advanced users. Female oral Primobolan dosages are usually recommended to be within the range of 50 – 70mg per day, and should present little risk of virilization.
Oral Primo should be administered once per day with no requirement to split up dosages throughout the day, as its half-life is about 2 – 3 days. Injectable Primobolan exhibits a half-life of 7 – 10 days due to the Enanthate ester, and should be administered twice per week, with each injection spaced evenly apart, in order to maintain stable and steady blood plasma levels.
Primobolan Information:
Primobolan (Methenolone)
Chemical Name: 17beta-Hydroxy-1-methyl-5alpha-androst-1-en-3-one, 1-methyl-1(5-alpha)-androsten-3-one-17b-ol
Molecular Weight: 414.621 g/mol
Formula: C27H42O3
Original Manufacturer: Squibb
Half Life: 10 days (Enanthate), 2 – 3 days (oral)
Detection Time: 4 – 5 weeks
Anabolic Rating: 88
Androgenic Rating: 44 – 57
References:
- Wiechert R. et al. Chem Ber. 93 (1960):1710.
- Methenolone acetate, Summary of information for clinical investigators, New Brunswick, NJ. The Squibb Institute for Medical Research, May 30, 1962.
- Anabolic effects of methenolone enanthate and methenolone acetate in underweight premature infants and children. New York State Journal of Medicine March 1, 1965, 645-8.
- Kruskemper H L et al, Exc Medica (Amsterd.) Congr. Ser. No. 51 (1962), 209.
- Weller O. Arzneimittelforsch. 12 (1962):234.
- Intern. Congr. Hormonal Steroids, Milan, 1962. Excerpta Med. Intern. Congr. Ser No. 51, p. 209. Excerpta. Med. Found., Amsterdam, 1962.
- Failure of non-17-alkylated anabolic steroids to produce abnormal liver function tests. J Clin Endocrinol Metab. 1964 Dec;24:1334-6.
- Fatal outcome of a patient with severe aplastic anemia after treatment with metenolone acetate. Ann Hematol. 1993 Jul;67(1):41-3. Tsukamoto N, Uchiyama T, Takeuchi T, Sato S, Naruse T, Nakazato Y.
- Comparative studies about the influence of metenolone acetate and mesterolone on hypophysis and male gonads. Trenkner R, Senge T, Hienz H et al. Arzneimittelforschung. 1970 20(4):545-7.
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