Androstenedione

4-androstenedioneandrost-4-ene-3,17-dioneandrostendione4-Androstene-3,17-dioneandrost-4-en-3,17-dioneAndrostenedione (4-androstenedione, A4)Δ 4 -Androstenedione
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4 -dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA).wikipedia
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Androgen

androgensandrogenicAndrogenic steroid
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4 -dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA).
Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development.

Dehydroepiandrosterone

DHEAAndrostenolone5-Dehydroepiandrosterone
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4 -dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA).
DHEA and other adrenal androgens such as androstenedione, although relatively weak androgens, are responsible for the androgenic effects of adrenarche, such as early pubic and axillary hair growth, adult-type body odor, increased oiliness of hair and skin, and mild acne.

Estrogen

oestrogenestrogensestrogenic
Androstenedione has been found to possess some estrogenic activity, similarly to other DHEA metabolites.
All of the different forms of estrogen are synthesized from androgens, specifically testosterone and androstenedione, by the enzyme aromatase.

Estradiol

17β-estradioloestradiol17-β-estradiol
However, in contrast to androstenediol, its affinity for the estrogen receptors is very low, with less than 0.01% of the affinity of estradiol for both the ERα and ERβ.
The major pathway involves the formation of androstenedione, which is then converted by aromatase into estrone and is subsequently converted into estradiol.

Androstenediol

5-androstenediol5-Androstene-3,17-dioladrostenediol
However, in contrast to androstenediol, its affinity for the estrogen receptors is very low, with less than 0.01% of the affinity of estradiol for both the ERα and ERβ. It is closely related to androstenediol (androst-5-ene-3β,17β-diol). Under the brand name Metharmon-F and in combination with sex steroids (pregnenolone, testosterone, estrone, androstenediol) and thyroid hormone (desiccated thyroid), androstenedione is or has been marketed for medical use in Thailand.
It is closely related to androstenedione (androst-4-ene-3,17-dione).

Estrone

oestroneTheelin
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4 -dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA). Under the brand name Metharmon-F and in combination with sex steroids (pregnenolone, testosterone, estrone, androstenediol) and thyroid hormone (desiccated thyroid), androstenedione is or has been marketed for medical use in Thailand.
The principal pathway involves androstenedione as an intermediate, with androstenedione being transformed into estrone by the enzyme aromatase.

3β-Hydroxysteroid dehydrogenase

3β-hydroxysteroid dehydrogenase/Δ 5-4 isomerase3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)isomerase3β-HSD
The primary pathway involves conversion of 17α-hydroxypregnenolone to DHEA by way of 17,20-lyase, with subsequent conversion of DHEA to androstenedione via the enzyme 3β-hydroxysteroid dehydrogenase.
3β-Hydroxysteroid dehydrogenase/Δ 5-4 isomerase (3β-HSD) is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone (DHEA) in the adrenal gland.

Adrenarche

In children aged 6 to 8 years old, there is a rise in androstenedione secretion along with DHEA during adrenarche.
During adrenarche the adrenal glands secrete increased levels of weak adrenal androgens, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione (A4), but without increased cortisol levels.

Adrenal gland

adrenal glandsadrenalsuprarenal gland
Androstenedione is produced in the adrenal glands and the gonads.
It produces androgens, mainly dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), and androstenedione (the precursor to testosterone) in humans.

Testosterone

low testosterone levels due to agingmetabolismprenatal exposure to androgens
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4 -dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA).
In addition, the 3β-hydroxyl group is oxidized by 3β-hydroxysteroid dehydrogenase to produce androstenedione.

17β-Hydroxysteroid dehydrogenase

17β-HSD17Beta Hydroxysteroid dehydrogenase17BHSD3
Conversion of androstenedione to testosterone requires the enzyme 17β-hydroxysteroid dehydrogenase.
This includes interconversion of DHEA and androstenediol, androstenedione and testosterone, and estrone and estradiol.

Aromatase

aromatizedCYP19A1aromatizable
Conversion of androstenedione to estrone requires the enzyme aromatase.
It catalyzes the last steps of estrogen biosynthesis from androgens (specifically, it transforms androstenedione to estrone and testosterone to estradiol).

5α-Reductase

5α-reduced5-alpha reductase5-alpha-reductase
Androstanedione is a 5α-reduced metabolite of 4-androstenedione which serves as an intermediate in the biosynthesis of the androgen and neurosteroid androsterone.
Specific substrates include testosterone, progesterone, androstenedione, epitestosterone, cortisol, aldosterone, and deoxycorticosterone.

Androsterone

Androstanedione is a 5α-reduced metabolite of 4-androstenedione which serves as an intermediate in the biosynthesis of the androgen and neurosteroid androsterone.
In addition, it can be converted back into DHT via 3α-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase, bypassing conventional intermediates such as androstenedione and testosterone, and as such, can be considered to be a metabolic intermediate in its own right.

Menopause

postmenopausalmenopausalpremenopausal
In premenopausal women, the adrenal glands and ovaries each produce about half of the total androstenedione (about 3 mg/day).
In contrast to the sudden fall in estradiol during menopause, the levels of total and free testosterone, as well as dehydroepiandrosterone sulfate (DHEAS) and androstenedione appear to decline more or less steadily with age.

17α-Hydroxypregnenolone

17-alpha-hydroxypregnenolone17-OH-Pregnenolone17α‑Hydroxypregnenolone
The primary pathway involves conversion of 17α-hydroxypregnenolone to DHEA by way of 17,20-lyase, with subsequent conversion of DHEA to androstenedione via the enzyme 3β-hydroxysteroid dehydrogenase.
17α-Hydroxypregneolone is also converted to 17α-hydroxyprogesterone, a prohormone for glucocorticosteroids and androstenedione through the activity of 3α-hydroxysteroid dehydrogenase.

Theca of follicle

theca celltheca cellsthecal cell
Androstenedione is released into the blood by theca cells.
The theca cells are responsible for the production of androstenedione, and indirectly the production of 17β estradiol, also called E2, by supplying the neighboring granulosa cells with androstenedione that with the help of the enzyme aromatase can be used as a substrate for this type of estradiol.

Patrick Arnold

Sports Illustrated credits Patrick Arnold with introducing androstenedione to the North American market.
Patrick Arnold (born 1966) is an American organic chemist known for introducing androstenedione, 1-androstenediol, and methylhexanamine into the dietary supplement market, and for creating the designer steroid tetrahydrogestrinone, also known as THG and "the clear".

Sex steroid

sex hormonesex hormonessex steroids
Androstenedione is the common precursor of the androgen and estrogen sex hormones. Under the brand name Metharmon-F and in combination with sex steroids (pregnenolone, testosterone, estrone, androstenediol) and thyroid hormone (desiccated thyroid), androstenedione is or has been marketed for medical use in Thailand.

Ketosteroid

17-ketosteroid17-ketosteroids11-oxosteroid
Androstenedione, also known as androst-4-ene-3,17-dione, is a naturally occurring androstane steroid and a 17-ketosteroid.

Pregnenolone

5-pregnenolone
Under the brand name Metharmon-F and in combination with sex steroids (pregnenolone, testosterone, estrone, androstenediol) and thyroid hormone (desiccated thyroid), androstenedione is or has been marketed for medical use in Thailand.

Testosterone (medication)

testosteronesynthetic testosteroneTestosteron
Under the brand name Metharmon-F and in combination with sex steroids (pregnenolone, testosterone, estrone, androstenediol) and thyroid hormone (desiccated thyroid), androstenedione is or has been marketed for medical use in Thailand.
In addition to ester and ether prodrugs, androgen prohormones or precursors of testosterone, such as dehydroepiandrosterone (DHEA), androstenediol, and androstenedione, exist as well, and convert into testosterone to variable extents upon oral ingestion.

Androstanedione

5α-Androstanedione
Androstanedione is a 5α-reduced metabolite of 4-androstenedione which serves as an intermediate in the biosynthesis of the androgen and neurosteroid androsterone.
Androstanedione, also known as 5α-androstanedione or as 5α-androstane-3,17-dione, is a naturally occurring androstane (5α-androstane) steroid and an endogenous metabolite of androgens like testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), and androstenedione.

Anabolic steroid

anabolic steroidsanabolic-androgenic steroidanabolic–androgenic steroid
It amended the Controlled Substance Act to place both anabolic steroids and prohormones on a list of controlled substances, making possession of the banned substances a federal crime.
Androgens such as testosterone, androstenedione and dihydrotestosterone are required for the development of organs in the male reproductive system, including the seminal vesicles, epididymis, vas deferens, penis and prostate.

Mark McGwire

Big MacBroken ManMcGwire
Androstenedione was legal and able to be purchased over the counter, and, as a consequence, it was in common use in Major League Baseball throughout the 1990s by record-breaking sluggers like Mark McGwire.
In a 1998 article by Associated Press writer Steve Wilstein, McGwire confessed to taking androstenedione, an over-the-counter muscle enhancement product that had already been banned by the World Anti-Doping Agency, the NFL, and the IOC; however, use of the substance was not prohibited by Major League Baseball at the time, and it was not federally classified as an anabolic steroid in the United States until 2004.