4-Androstenediol is an androstenediol

Androstenediol

Androstenediol may refer to:* 4-Androstenediol, the steroid androgen that can be converted to testosterone* 5-Androstenediol, steroid* Methandriol, a synthetic androstenediol derivative...

 that is converted to 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...

. The conversion rate is about 15.76%, almost triple that of androstenedione

Androstenedione

Androstenedione is a 19-carbon steroid hormone produced in the adrenal glands and the gonads as an intermediate step in the biochemical pathway that produces the androgen testosterone and the estrogens estrone and estradiol.-Synthesis:Androstenedione is the common precursor of male and female sex...

, due to utilization of a different enzymatic pathway. There is no direct conversion to estrogen

Estrogen

Estrogens , 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...

, though some secondary aromatization does occur through metabolism. 4-Androstenediol is less androgenic, since it does not metabolize into the potent androgen dihydrotestosterone

Dihydrotestosterone

Dihydrotestosterone is an androgen or male sex hormone. The enzyme 5α-reductase synthesises DHT in the prostate, testes, hair follicles, and adrenal glands...

 (DHT).

4-Androstenediol is closer to 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...

 structurally than 5-androstenediol, and has androgen

Androgen

Androgen, 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 effects.

Medical and commercial use

Patrick Arnold

Patrick Arnold

Patrick Arnold is an American organic chemist responsible for creating the designer steroid tetrahydrogestrinone, also known as THG and "the clear". THG, along with two other anabolic steroids that Patrick Arnold manufactured , were drugs at the heart of the BALCO scandal...

holds a 1999 patent on "Use of 4-androstenediol to increase testosterone levels in humans".