5α-Dihydronandrolone (also known as 5α-DHN, dihydronandrolone, DHN, 5α-dihydro-19-nortestosterone, or 5α-estran-17β-ol-3-one) is a
naturally occurring
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synt ...
anabolic–androgenic steroid
Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...
(AAS) and a
5α-reduced derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. F ...
of
nandrolone
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...
(19-nortestosterone).
It is a major
metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
of nandrolone and is formed from it by the actions of the
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
5α-reductase
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...
analogously to the formation of
dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includi ...
(DHT) from
testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testes and prostate, as well as promoting secondar ...
.
When testosterone is 5α-reduced into DHT, which is a much more potent AAS in comparison, its effects are potentiated on a local level.
The tissues in which this occurs (i.e., the tissues that express 5α-reductase) are referred to as "androgenic" tissues and include the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
,
hair follicle
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
s, and
prostate gland
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and physio ...
, among others.
The conversion of testosterone into DHT is an important factor in the
etiology
Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek (''aitiología'') "giving a reason for" (, ''aitía'', "cause"); and ('' -logía''). More completely, e ...
of a variety of
androgen-dependent condition An androgen-dependent condition, disease, disorder, or syndrome, is a medical condition that is, in part or full, dependent on, or is sensitive to, the presence of androgenic activity in the body.
Known androgen-dependent conditions include acne, s ...
s, including
acne
Acne, also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, black ...
,
excessive facial/body hair growth,
scalp hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front ha ...
,
prostate enlargement
Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, inability to urinate, or loss o ...
, and
prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...
.
Unlike the case of testosterone and DHT, 5α-DHN is a much weaker
agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
of the
androgen receptor
The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone in th ...
(AR) than is nandrolone.
For this reason, instead of local potentiation in androgenic tissues, there is a local inactivation when nandrolone is converted into 5α-DHN by 5α-reductase in these tissues.
This is thought to be largely or completely responsible for the exceptionally high ratio of
anabolic
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-do ...
to
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This inc ...
ic effects seen with nandrolone.
The combination of nandrolone with a
5α-reductase inhibitor
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...
like
finasteride
Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of horm ...
or
dutasteride
Dutasteride, sold under the brand name Avodart among others, is a medication primarily used to treat the symptoms of a benign prostatic hyperplasia (BPH), an enlarged prostate not associated with cancer. A few months may be required before benefi ...
will block the conversion of nandrolone into 5α-DHN and, unlike with testosterone and various other AAS, thereby considerably increase the propensity of nandrolone for producing androgenic
side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s.
See also
*
19-Norandrosterone
*
19-Noretiocholanolone
*
5α-Dihydronorethandrolone
5α-Dihydronorethandrolone (5α-DHNED), also known as 17α-ethyl-4,5α-dihydro-19-nortestosterone or as 17α-ethyl-5α-estran-17β-ol-3-one, is an androgen/ anabolic steroid and a metabolite of norethandrolone (as well as of the prodrug ethyles ...
*
5α-Dihydronorethisterone
5α-Dihydronorethisterone (5α-DHNET, dihydronorethisterone, 17α-ethynyl-5α-dihydro-19-nortestosterone, or 17α-ethynyl-5α-estran-17β-ol-3-one) is a major active metabolite of norethisterone (norethindrone). Norethisterone is a progestin wit ...
*
5α-Dihydrolevonorgestrel
5α-Dihydrolevonorgestrel (5α-DHLNG) is an active metabolite of the progestin levonorgestrel which is formed by 5α-reductase. It has about one-third of the affinity of levonorgestrel for the progesterone receptor. In contrast to levonorgestrel, ...
*
5α-Dihydroethisterone
References
{{DEFAULTSORT:Dihydronandrolone, 5α-
5α-Reduced steroid metabolites
Cyclopentanols
Androgens and anabolic steroids
Estranes
Human drug metabolites
Ketones