Prohormone
Encyclopedia
A prohormone is a substance that is a precursor to a hormone
, usually having minimal hormonal effect by itself. The term has been used in medical science since the middle of the 20th century. The primary function of a prohormone is to enhance the strength of the hormone that already occurs in the body. Prohormones add no hormones whereas steroids add hormones which commonly causes confusion between the two. Examples of natural, human prohormones include proinsulin
and pro-opiomelanocortin.
For peptide hormone
s, the conversion process from prohormone to hormone typically occurs after export to the endoplasmic reticulum
and often requires multiple processing enzymes. For example, proinsulin is processed by PC 1/2, PC 3, and carboxypeptidase E to afford insulin. Proamylin, which is cosecreted with proinsulin, requires the above three factors and an amidating monoxygenase.
For small molecule hormones, the conversion is often one step, and is often used to regulate hormone levels.
A typical prohormone is intended to be a precursor of an anabolic steroid
like testosterone
, which is taken in order to boost the body’s available hormone supply. These precursors are intended to be converted to full, active hormones via an enzymatic
process that occurs during metabolism
, typically resulting in the addition of whichever atoms happen to be missing from the chemical structure of the compound.
Prohormones are used mainly by athletes looking to increase size, strength, endurance, reduce recovery time or add lean body mass. They are most often used for increasing muscle mass or reducing body fat levels. Life extension groups are also increasingly using prohormones as a means of hormone replacement therapy, as an alternative to prescription drug use. Additionally there is a movement to use prohormones of androgens to help offset the damaging effects of environmental androgens on the body. Chemical endocrine disruptor agents like bisphenol A are becoming recognized as having the ability to skew the androgen to estrogen ratio. This skewed ratio can have many bad effects on men, including sexual performance, impotence and other testosterone dependent body functions.
The use of prohormones has become popular among bodybuilders, since the effects can be similar (though normally much less drastic) to those achieved through the use of synthetic anabolic steroids, including gains in muscular strength and hypertrophy
. There are currently many companies manufacturing prohormone products for this purpose.
Prohormones have the same side effects as anabolic steroids, and are dependent upon the user as to which side effects one might experience. Some side effects are acne, hair loss, breast tissue enlargement, and prostate swelling however these are specific to each type of prohormone and reports of side effects are usually very minimal.
The potential for these side effects does exist, but it can be reduced if one uses proper precautionary measures such as post cycle therapy (PCT). Generally, if a person is genetically predisposed to a side effect it will occur (i.e.: if someone has a history of male pattern baldness in the family, it could be assumed that this could be a side effect experienced if prohormones are used)
On October 22, 2004, President Bush
signed into law the Anabolic Steroid Control Act of 2004 (118 Stat. 1661).
The bill was written to become effective in 90 days, which was January 20, 2005. This legislation places both anabolic steroids and some prohormones on a list of controlled substance
s (a new type of "regulatory control"). This bans the selling or possessing of only the following prohormones.
Prohormones Added To The List Of Schedule III Anabolic Steroids:
androstanediol—3b,17b-dihydroxy-5a-androstane; and 3a,17b-dihydroxy-5a-androstane;
androstanedione (5a-androstan-3,17-dione);
1-androstenediol (3a,17b-dihydroxy-5a-androst-1-ene);
4-androstenediol (3b,17b-dihydroxy-androst-4-ene); and 5-androstenediol (3b,17b-dihydroxy-androst-5-ene);
1-androstenedione ([5a]-androst-1-en-3,17-dione);
4-androstenedione (androst-4-en-3,17-dione); and 5-androstenedione (androst-5-en-3,17-dione);
norandrostenediol—19-nor-4-androstenediol (3b, 17b-dihydroxyestr-4-ene);
19-nor-4-androstenediol (3a, 17b-dihydroxyestr-4-ene);
19-nor-5-androstenediol (3b, 17b-dihydroxyestr-5-ene); and 19-nor-5-androstenediol (3a, 17b-dihydroxyestr-5-ene);
norandrostenedione—19-nor-4-androstenedione (estr-4-en-3,17-dione); and 19-nor-5-androstenedione (estr-5-en-3,17-dione;
and any salt, ester, or ether of a drug or substance described in this paragraph
4-androstenediol
19-norandrostenedione
1-testosterone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
, usually having minimal hormonal effect by itself. The term has been used in medical science since the middle of the 20th century. The primary function of a prohormone is to enhance the strength of the hormone that already occurs in the body. Prohormones add no hormones whereas steroids add hormones which commonly causes confusion between the two. Examples of natural, human prohormones include proinsulin
Proinsulin
Proinsulin is the prohormone precursor to insulin made in the beta cells of the islets of Langerhans, specialized regions of the pancreas. In humans, proinsulin is encoded by the INS gene.- Synthesis and post-translational modification :...
and pro-opiomelanocortin.
For peptide hormone
Peptide hormone
Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.Like other proteins, peptide hormones are synthesized in cells from amino acids according to an mRNA template, which is itself synthesized from a DNA template inside the...
s, the conversion process from prohormone to hormone typically occurs after export to the endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...
and often requires multiple processing enzymes. For example, proinsulin is processed by PC 1/2, PC 3, and carboxypeptidase E to afford insulin. Proamylin, which is cosecreted with proinsulin, requires the above three factors and an amidating monoxygenase.
For small molecule hormones, the conversion is often one step, and is often used to regulate hormone levels.
Prohormones of testosterone and other androgenic steroids
In the last two decades, prohormones have also been used by bodybuilders, athletes, and nonmedical users of anabolic steroids and other hormones to refer to substances that are expected to convert to active hormones in the body. The intent is to provide the benefits of taking an anabolic steroid without the legal risks, and to achieve the hoped-for benefits or advantages without use of anabolic steroids themselves. Many of these compounds are legal to manufacture, sell, possess and ingest eliminating the legal problems associated with schedule III anabolic steroids. The typical definition of "prohormone" includes a steroidal molecule that has the opposite molecular structure to testosterone on either the 3a/b position or the 17b position. Testosterone has a ketone group on the 3 carbon and a hydroxyl on the 17b carbon. A steroid with modifications away from testosterone in one or both of these areas is commonly referred to as a "prohormone". These enzymatic changes occur with the body's bidirectional enzymes.A typical prohormone is intended to be a precursor of an anabolic steroid
Anabolic steroid
Anabolic steroids, technically known as anabolic-androgen steroids or colloquially simply as "steroids", are drugs that mimic the effects of testosterone and dihydrotestosterone in the body. They increase protein synthesis within cells, which results in the buildup of cellular tissue ,...
like testosterone
Testosterone
Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...
, which is taken in order to boost the body’s available hormone supply. These precursors are intended to be converted to full, active hormones via an enzymatic
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
process that occurs during metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
, typically resulting in the addition of whichever atoms happen to be missing from the chemical structure of the compound.
Prohormones are used mainly by athletes looking to increase size, strength, endurance, reduce recovery time or add lean body mass. They are most often used for increasing muscle mass or reducing body fat levels. Life extension groups are also increasingly using prohormones as a means of hormone replacement therapy, as an alternative to prescription drug use. Additionally there is a movement to use prohormones of androgens to help offset the damaging effects of environmental androgens on the body. Chemical endocrine disruptor agents like bisphenol A are becoming recognized as having the ability to skew the androgen to estrogen ratio. This skewed ratio can have many bad effects on men, including sexual performance, impotence and other testosterone dependent body functions.
The use of prohormones has become popular among bodybuilders, since the effects can be similar (though normally much less drastic) to those achieved through the use of synthetic anabolic steroids, including gains in muscular strength and hypertrophy
Muscle hypertrophy
Muscle hypertrophy is an increase in the size of muscle cells. It differs from muscle hyperplasia, which is the formation of new muscle cells.-Hypertrophy stimuli:A range of stimuli can increase the volume of muscle cells...
. There are currently many companies manufacturing prohormone products for this purpose.
Prohormones have the same side effects as anabolic steroids, and are dependent upon the user as to which side effects one might experience. Some side effects are acne, hair loss, breast tissue enlargement, and prostate swelling however these are specific to each type of prohormone and reports of side effects are usually very minimal.
The potential for these side effects does exist, but it can be reduced if one uses proper precautionary measures such as post cycle therapy (PCT). Generally, if a person is genetically predisposed to a side effect it will occur (i.e.: if someone has a history of male pattern baldness in the family, it could be assumed that this could be a side effect experienced if prohormones are used)
On October 22, 2004, President Bush
George W. Bush
George Walker Bush is an American politician who served as the 43rd President of the United States, from 2001 to 2009. Before that, he was the 46th Governor of Texas, having served from 1995 to 2000....
signed into law the Anabolic Steroid Control Act of 2004 (118 Stat. 1661).
The bill was written to become effective in 90 days, which was January 20, 2005. This legislation places both anabolic steroids and some prohormones on a list of controlled substance
Controlled substance
A controlled substance is generally a drug or chemical whose manufacture, possession, or use are regulated by a government. This may include illegal drugs and prescription medications ....
s (a new type of "regulatory control"). This bans the selling or possessing of only the following prohormones.
Prohormones Added To The List Of Schedule III Anabolic Steroids:
androstanediol—3b,17b-dihydroxy-5a-androstane; and 3a,17b-dihydroxy-5a-androstane;
androstanedione (5a-androstan-3,17-dione);
1-androstenediol (3a,17b-dihydroxy-5a-androst-1-ene);
4-androstenediol (3b,17b-dihydroxy-androst-4-ene); and 5-androstenediol (3b,17b-dihydroxy-androst-5-ene);
1-androstenedione ([5a]-androst-1-en-3,17-dione);
4-androstenedione (androst-4-en-3,17-dione); and 5-androstenedione (androst-5-en-3,17-dione);
norandrostenediol—19-nor-4-androstenediol (3b, 17b-dihydroxyestr-4-ene);
19-nor-4-androstenediol (3a, 17b-dihydroxyestr-4-ene);
19-nor-5-androstenediol (3b, 17b-dihydroxyestr-5-ene); and 19-nor-5-androstenediol (3a, 17b-dihydroxyestr-5-ene);
norandrostenedione—19-nor-4-androstenedione (estr-4-en-3,17-dione); and 19-nor-5-androstenedione (estr-5-en-3,17-dione;
and any salt, ester, or ether of a drug or substance described in this paragraph
4-androstenedione
- Converts to: testosterone via 17bHSD
- Characteristics:
- Research indicates a conversion rate of about 5.9%, which means that of the amount taken orally, 5.9% is converted to testosterone.
- Relatively high rate of aromatization to estrogenEstrogenEstrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
s, and consequently higher risk of side-effects such as gynecomastiaGynecomastiaGynecomastia or Gynaecomastia, , is the abnormal development of large mammary glands in males resulting in breast enlargement. The term comes from the Greek γυνή gyné meaning "woman" and μαστός mastós meaning "breast"...
brought on by excessive estrogen formation. - Exhibits significant androgenAndrogenAndrogen, also called androgenic hormone or testoid, is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of male characteristics in vertebrates by binding to androgen receptors...
ic properties, which may result in side effects such as male pattern baldness, acneAcne vulgarisAcne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
, and enlarged prostateProstateThe prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
. - A recent study looking at the long term effects of androstenedione use in rats for their entire life cycle showed no increase in mortality over a control group, showing that androstenedione and presumably all prohormones without chemical modifications to be reasonably safe.
4-androstenediol4-Androstenediol4-Androstenediol is an androstenediol that is converted to testosterone. The conversion rate is about 15.76%, almost triple that of androstenedione, due to utilization of a different enzymatic pathway. There is no direct conversion to estrogen, though some secondary aromatization does occur...
(4-AD)
- Converts to: testosterone via 3bHSD
- Characteristics:
- Conversion rate of about 15.76%, almost triple that of androstenedione, due to utilization of a different enzymatic pathway.
19-norandrostenedione19-Norandrostenedione19-Norandrostenedione is a precursor of the anabolic steroid nandrolone. Until 2005 19-Norandrostenedione was available without prescription in United States, where it was marketed as a prohormone, but it is now classified as a Schedule III drug...
- Converts to: nortestosterone (also called nandrolone) via 17bHSD
- Characteristics:
- Only slightly less anabolic than testosterone.
- Low rate of aromatization to estrogens.
- Low occurrence of androgenic side effects.
19-norandrostenediol
- Converts to: nortestosterone vis 3bHSD
- Characteristics:
- Low occurrence of androgenic side effects.
1-androstenediol (1-AD)
- Converts to: 1-testosterone, a 5-alpha reduced 1-ene steroid; 1-testosterone is better (although rarely) described as dihydroboldenone, the 5-alpha reduced5-alpha reductase5α-reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in 3 metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism, and prostate cancer....
version of the naturally occurring steroid boldenone - Characteristics:
- Cannot aromatize to estrogen either directly or through any of its metabolic products. However, 1-Testosterone, being a 5-alpha reduced steroid, is highly androgenic; it is very similar to Dihydrotestosterone (DHT). Many side effects associated with excessive levels of DHT, including male pattern baldness, testicular shrinkage, benign prostate hypertrophy and acne can occur with 1-AD usage. (Journal of Organic chem. vol, 27 1962 iss.1)
1,4-androstadienedione (1,4 AD)
- Converts to: boldenoneBoldenoneBoldenone , also known under the trade names Equipoise, Ganabol, Equigan and Ultragan, is an anabolic steroid developed for veterinary use, mostly for treatment of horses...
- Characteristics:
- High level of oral bioavailability.
- Low rate of aromatization to estrogens (approximately half that of testosterone).
- Low occurrence of androgenic side effects.
1-testosterone1-Testosterone1-Testosterone is an anabolic steroid that differs from testosterone by having a 1,2-double bond instead of 4,5-double bond in its A ring...
(1-T)
- Characteristics:
- similar to testosterone except instead of a 4,5-double bond it has a 1,2-double bond.
- has about 20% oral bioavailability compared with less than 5% for testosterone
- non-aromatizing to estrogen or DHT
- has irritative properties making it too painful to inject, and has extremely bitter taste, making transcutaneous topical solutions the only practical human delivery method. It was commercialized this way in the United States before 2005, when it became illegal together with many other prohormones.
- History: 1-T was discovered in the 1950s, explored as a potential anabolic product by the pharmaceutical company G.D. Searle, but not commercialized at the time due to difficulty in delivery.
- Also considered a steroid