Testosterone 5 Alpha Reductase

Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.


Are You Feeling Fatigued, Have Low Libido Or Are Suffering From Mood Swings? 

Understanding testosterone 5 alpha reductase may hold the answer to resolving these problems and reaching optimal male hormone balance.

Testosterone plays an essential role in male bodily development and wellbeing, including muscle growth, bone density and overall wellbeing.

But to maximize its effects, testosterone must first be converted to dihydrotestosterone (DHT) through 5 alpha reductase enzyme.

Here we examine its intricate workings as well as its influence on testosterone levels and male health.

Through this exploration, we aim to illuminate the significance of testosterone 5 alpha reductase for improving hormone balance for optimal vitality and well-being.

If you want to take control of your hormones and regain vitality, read along as we explore this fascinating world of 5 alpha reductase!

Testosterone and 5 Alpha Reductase

Testosterone and its metabolites are important neuroactive steroids that play an essential role in neurophysiological processes.

More specifically, they've been implicated in promoting neurogenesis, myelination/remyelination processes, neuroprotection measures and attenuating stress responses.

Children affected by testosterone 5 alpha reductase deficiency may not show symptoms until puberty.

When they do, treatment will depend on both gender identity and how the individual would like to be treated.

What is 5 alpha reductase

The 5-alpha reductase enzyme is responsible for converting testosterone to dihydrotestosterone (DHT), the male sexual hormone found in target tissues such as skin, liver, prostate and hair follicles.

5-alpha reductase inhibitors decrease production of DHT while simultaneously blocking it from binding with its androgen receptors in target areas - finasteride is one such 5-alpha reductase inhibitor which has become widely used to treat benign prostatic hyperplasia and male pattern baldness.

5-alpha reductase deficiency is a genetic condition that impacts sexual development from before birth to puberty.

People living with this disorder have one X and one Y chromosome each and have external male genitals; however, their bodies do not produce enough DHT hormone - essential for male sexual development.

People living with this condition may still be able to have children, though they may require assisted fertility treatments and surgery for penile deformities like hypospadias.

Some individuals choose female identification while others choose male; there is no right or wrong decision; each should based on one's internal sense of self.

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how does 5 alpha reduct affect testosterone levels

5 alpha reductase is an enzyme responsible for converting testosterone to dihydrotestosterone (DHT), playing an integral part in male sexual development and formation, including external genitalia formation and muscle growth.

A genetic mutation may reduce enzyme levels leading to decreased testosterone and an increase in DHT; this condition is known as 5-alpha reductase deficiency.

5-alpha reductase can be found in the prostate, skin and hair follicles and is responsible for converting testosterone to two more potent androgens - estradiol 17-beta and DHT - which act to induce masculine characteristics like deep voices, facial hair growth and muscle development.

These androgens interact with androgen receptors to cause deep voices, facial hair growth and muscle expansion.

Many patients with male pseudohermaphroditism were reported as suffering from 5 -reductase deficiency, leading to impaired virilization during puberty.

These patients exhibited a broad spectrum of phenotypic features and displayed female external genitalia characterized by clitoromegaly, blind vagina pouches or microphallus.

5-alpha-reductase enzymes convert testosterone to dihydrotestosterone (5-dihydrotestosterone, DHT).

Cloning of genes encoding 5-alpha-reductase 2 (gene SRD5A2) and 5 -reductase 1 (gene SRD5A1) revealed their distinct functions in vivo; type-2 (5-alpha-reductase) isoenzymes promote virilization while type-1 skin isoenzymes inhibit it.

Administration of ORX to MK-treated animals produced small changes to serum and prostate testosterone levels but led to an overall reduction of DHT production.

The importance of optimal testosterone

Testosterone plays an essential role in men's overall health. Low levels can result in various symptoms, including erectile dysfunction and decreased sexual desire; muscle mass reduction; bone density loss; decreased motivation; and loss of motivation and self-confidence.

Testosterone (T) can be converted to dihydrotestosterone (DHT) through 5-alpha reductase isoenzymes in cells, using as a cofactor nicotinamide adenine dinucleotide phosphate (5-alpha-R).

DHT has more potency as an androgen and can bind more strongly with androgen receptors than does testosterone.

SRD5A2 encodes instructions for producing 5 alpha reductase, an enzyme responsible for breaking down testosterone to be converted to its active form; mutations to this gene may result in 5-alpha reductase deficiency - an autosomal recessive disorder affecting people with 46,XY karyotype and manifesting itself with undervirilization of external genitalia and decreased testosterone production during puberty.

Animal observations show that males with higher testosterone levels tend to outwit competition for mating partners more easily, which recent research backs up as true for humans as well.

Testosterone can help men feel more secure and confident, which gives them an edge in love life or work environments.

Common symptoms of imbalanced testosterone levels

Testosterone, produced in the testicles, is an essential male sexual hormone produced during puberty to promote male traits like body and facial hair growth, deepened voice pitch, increased muscle strength and greater bone mineral density.

As men age, their testosterone levels may begin to decline gradually leading to Low Testosterone Syndrome or Low T for short.

An inadequate testosterone supply can result in many symptoms, including muscle mass loss, fatigue, weight gain and low libido.

Furthermore, low-T treatments may help alleviate these problems as well as mood swings and memory impairment. Low-T treatment offers men an effective solution to address their hormonal imbalance and enhance quality of life.

Testosterone replacement therapy can be administered using topical gel applied directly to the skin every day or intramuscular injections.

Your physician can conduct blood tests to measure total testosterone levels as well as luteinizing hormone and prolactin levels to assess contributing factors and then discuss which options would work best in your particular case.

Factors that can affect 5 alpha reductase activity

5 alpha reductase converts testosterone into dihydrotestosterone, an even more potent androgen.

This process is essential for male sexual development and the formation of external genitalia and prostate formation.

About 4-8% of testosterone produced in men is converted to 5-alpha-dihydrotestosterone via target cells converting it further; dihydrotestosterone also binds more tightly to androgen receptors than does testosterone thus amplifying its signal.

5-alpha-reductase deficiency is a genetic condition in which enzyme levels drop significantly, leaving infants born with this condition to have unclear genital features that may include small penis (micropenis), hypospadias or an unusual urogenital sinus and pouch structure (clitoris-like).

Traditionally, affected babies were raised as females until puberty when they underwent virilization to become males.

5-alpha-reductase inhibitors are medications designed to block the activity of this enzyme and lower levels of dihydrotestosterone in the body, helping control prostate growth while decreasing male pattern hair loss.

Common 5-alpha-reductase inhibiting drugs include finasteride and dutasteride; natural compounds also known as 5-alpha-reductase inhibators include lingzhi mushroom extract and saw palmetto.

Natural ways to optimize 5 alpha reductase

Dihydrotestosterone (DHT), an anabolic hormone produced from testosterone, is one of the best ways to combat benign prostatic hyperplasia (BPH).

Two steroid 5 alpha reductase inhibitor drugs approved for clinical use - dutasteride and finasteride - have proven highly successful at this.

Foods rich in lycopene, zinc, biotin and omega-3 fatty acids may help inhibit 5-alpha reductase activity and thus lower DHT levels in the body - this may prevent hair loss in men while simultaneously encouraging hair growth among women.

Quercetin-rich foods can help limit the activities of an enzyme and lower oxidative stress levels, helping prevent DHT production and ultimately baldness.

The role of diet and exercise in testosterone

Men's health relies heavily on testosterone levels being optimal; this hormone promotes muscle development, increases bone density and strength, helps with libido and prostate health, as well as having an impactful role in libido and health libido and prostate health.

Maintaining healthy levels is also critical in terms of disease risk reduction; there are various natural ways to boost testosterone.

Among them is lifting weights - studies have proven its efficacy at increasing 5 alpha reductase's sensitivity to androgens.

A diet rich in proteins may also help increase testosterone.

One study that observed the effects of a low-fat, high-fiber diet on testosterone levels discovered that when processed foods such as chips or pizza were included in the diet, testosterone levels decreased dramatically.

Studies have repeatedly shown the power of resistance exercises to significantly raise basal or resting serum testosterone concentrations, with these increases remaining elevated following exercise cessation.

Galbo et al. conducted an experiment comparing different lower body multi-joint movements using free weight (squats) vs machine weight (leg press). They discovered squats produced a greater rise in plasma testosterone than leg presses did.


Testosterone is the predominant circulating androgen among men, but in order to exert its effects it must first be converted to two active metabolites, estradiol 17-beta and dihydrotestosterone (DHT).

Conversion occurs most effectively within prostate gland cells where DHT binds more strongly than testosterone with androgen receptors, producing stronger ligand-receptor complexes and more than three times greater potency of androgen action compared with testosterone.

Human bodies contain 5 alpha reductase enzymes that convert testosterone to DHT by hydrolyzing carbons 4 and 5, requiring cofactor nicotinamide adenine dinucleotide phosphate (NADPH).

Their activity increases significantly when tissues contain high concentrations of androgen receptors; moreover, 5 alpha reductase converts approximately 90% of testosterone into DHT in prostate tissue alone and thus plays an essential role in androgen-induced effects in this tissue.

Mutations that lead to 5 alpha reductase deficiency are found throughout the gene for this enzyme and, among those affected by it, present themselves with various symptoms.

Most commonly seen among them is an increase in male external genitalia size along with clitoromegaly; however, other symptoms could include microphallus or hypospadias.

Finasteride is a selective inhibitor of 5 alpha reductase that blocks DHT production in the prostate gland, leading to reduced prostatic size and success treating benign prostatic hyperplasia.

Furthermore, Finasteride has proven successful at treating female-pattern hair loss associated with hyperandrogenism as well as decreasing risks for prostate cancer.

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