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Category: Best Natural Testosterone Boosters

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass, and the growth of body hair. On average, in adult human males, the plasma concentration of testosterone is about 7-8 times as great as the concentration in adult human females' plasma, but as the metabolic consumption of testosterone in males is greater, the daily production is about 20 times greater in men. In general, androgens promote protein synthesis and growth of those tissues with androgen receptors. During the 2nd trimester androgen level is associated with Gender identity This period affects the femininization or masculinization of the fetus and can be a better predictor of feminine or mascular behaviours such as sex typed behaviour than an adult's own levels. Pre- Peripubertal effects are the first observable effects of rising androgen levels at the end of childhood, occurring in both boys and girls. Pubertal effects begin to occur when androgen has been higher than normal adult female levels for months or years.
Adult testosterone effects are more clearly demonstrable in males than in females, but are likely important to both sexes.
Falling in love decreases men's testosterone levels while increasing women's testosterone levels. Testosterone levels do not rely on physical presence of a partner for men engaging in relationships (same-city vs.
Physical presence may be required for women who are in relationships for the testosterone-partner interaction, where same-city partnered women have lower testosterone levels than long-distance partnered women. It has been found that when testosterone and endorphins in ejaculated semen meet the cervical wall after sexual intercourse, females receive a spike in testosterone, endorphin, and oxytocin levels, and males after orgasm during copulation experience an increase in endorphins and a marked increase in oxytocin levels. There are positive correlations between positive orgasm experience in women and testosterone levels where relaxation was a key perception of the experience.
An increase in T levels has also been found to occur in both men and women who have orgasms that are masturbation-induced. Studies conducted on rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. In one study, almost every mammalian species examined demonstrated a marked increase in a male's testosterone level upon encountering a novel female. In non-human primates it has been suggested that testosterone in puberty stimulates sexual motivation, which allows the primate to increasingly seek out sexual experiences with females and thus creates a sexual preference for females. Higher levels of testosterone were associated with periods of sexual activity within subjects, but between subjects testosterone levels were higher for less sexually active individuals. Men who watch a sexually explicit movie have an average increase of 35% in testosterone, peaking at 60a€“90 minutes after the end of the film, but no increase is seen in men who watch sexually neutral films.
Mena€™s levels of testosterone, a hormone known to affect mena€™s mating behaviour, changes depending on whether they are exposed to an ovulating or nonovulating womana€™s body odour.
In a 1991 study, males were exposed to either visual or auditory erotic stimuli and asked to complete a cognitive task, where the number of errors on the task indicated how distracted the participant was by the stimuli. Sperm competition theory: Testosterone levels are shown to increase as a response to previously neutral stimuli when conditioned to become sexual in male rats.
Androgens may modulate the physiology of vaginal tissue and contribute to female genital sexual arousal.
Womena€™s levels of testosterone are higher when measured pre-intercourse vs pre-cuddling, as well as post-intercourse vs post-cuddling.
LA?pez, Hay, and Conklin (2009) found that women who are non-pill users experience a significant increase in testosterone levels in response to viewing a video of an attractive man courting a young woman. When females have a higher baseline level of testosterone, they had higher increases in sexual arousal levels but smaller increases in testosterone, indicating a ceiling effect on testosterone levels in females. Van Anders and Dunn (2009) also studied the link between testosterone and orgasms in women, and found a correlation between high T levels and positive orgasm experience. The administration of testosterone makes men selfish and more likely to punish others for being selfish towards them.
There are some differences between a male and female brain (possibly the result of different testosterone levels), one of them being size: the male human brain is, on average, larger.
A study conducted in 1996 found no immediate short term effects on mood or behavior from the administration of supraphysiologic doses of testosterone for 10 weeks on 43 healthy men. Literature suggests that attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans.
The "evolutionary neuroandrogenic theory" focuses on the hormone testosterone as a factor influencing aggression and criminality and being evolutionary beneficial during certain forms of competition. The original and primary use of testosterone is for the treatment of males who have too little or no natural endogenous testosterone productiona€”males with hypogonadism. However, over the years, as with every hormone, testosterone or other anabolic steroids has also been given for many other conditions and purposes besides replacement, with varying success but higher rates of side effects or problems.
To take advantage of its virilizing effects, testosterone is often administered to transsexual men as part of the hormone replacement therapy, with a "target level" of the normal male testosterone level.
There is not total agreement on the threshold of testosterone value below which a man would be considered hypogonadal. Replacement therapy can take the form of injectable depots, transdermal patches and gels, subcutaneous pellets, and oral therapy. Large scale trials to assess the efficiency and long-term safety of testosterone are still lacking. However, a 2000 article in The Journal of Urology showed an association of low testosterone with prostate cancer. The apparent conflict in the results of these two papers can be resolved when we remember that prostrate cancer is very common.
Testosterone can be used by an athlete in order to improve performance, but it is considered to be a form of doping in most sports.
Anabolic steroids (including testosterone) have also been taken to enhance muscle development, strength, or endurance.
A number of methods for detecting testosterone use by athletes have been employed, most based on a urine test. Like other steroid hormones, testosterone is derived from cholesterol (see figure to the left).[102] The first step in the biosynthesis involves the oxidative cleavage of the sidechain of cholesterol by CYP11A, a mitochondrial cytochrome P450 oxidase with the loss of six carbon atoms to give pregnenolone. The amount of testosterone synthesized is regulated by the hypothalamic-pituitary-testicular axis (see figure to the right).[107] When testosterone levels are low, gonadotropin-releasing hormone (GnRH) is released by the hypothalamus which in turn stimulates the pituitary gland to release FSH and LH. Approximately 7% of testosterone is reduced to 5I±-dihydrotestosterone (DHT) by the cytochrome P450 enzyme 5I±-reductase,[122] an enzyme highly expressed in male accessory sex organs and hair follicles. DHT is a more potent form of testosterone while estradiol has completely different activities (feminization) compared to testosterone (masculinization). Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5I±-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5-alpha reductase. Androgen receptors occur in many different vertebrate body system tissues, and both males and females respond similarly to similar levels.
The bones and the brain are two important tissues in humans where the primary effect of testosterone is by way of aromatization to estradiol. The human hormone testosterone is produced in greater amounts by males, and less by females.


A number of synthetic analogs of testosterone have been developed with improved bioavailability and metabolic half life relative to testosterone.
Testosterone insufficiency (also termed hypotestosteronism or hypotestosteronemia) is an abnormally low testosterone production.
The trail remained cold until the University of Chicagoa€™s Professor of Physiologic Chemistry, Fred C. The Organon group in the Netherlands were the first to isolate the hormone, identified in a May 1935 paper "On Crystalline Male Hormone from Testicles (Testosterone)".[134] They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[137] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887a€“1976) and A. The partial synthesis in the 1930s of abundant, potent testosterone esters permitted the characterization of the hormonea€™s effects, so that Kochakian and Murlin (1936) were able to show that testosterone raised nitrogen retention (a mechanism central to anabolism) in the dog, after which Allan Kenyona€™s group[140] was able to demonstrate both anabolic and androgenic effects of testosterone propionate in eunuchoidal men, boys, and women. The First Step: If you are interested in starting a program, contact us for a free consultation. All of our Board Certified Medical Physicians and Doctors are knowledgeable specialists in prescribing HGH, Testosterone, Sermorelin, and HCG Weight Loss Diet. In mammals, testosterone is primarily secreted in the testicles of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. In addition, testosterone is essential for health and well-being as well as the prevention of osteoporosis.
Testosterone effects can be classified as virilizing and anabolic, though the distinction is somewhat artificial, as many of the effects can be considered both. For postnatal effects in both males and females, these are mostly dependent on the levels and duration of circulating free testosterone. A mother's own testosterone level influences behavior more than the daughters's testosterone level during pregnancy. In males, these are usual late pubertal effects, and occur in women after prolonged periods of heightened levels of free testosterone in the blood.
Some of these effects may decline as testosterone levels decrease in the later decades of adult life. It is speculated that these changes in testosterone result in the temporary reduction of differences in behavior between the sexes. This adds to the hospitable physiological environment in the female internal reproductive tract for conceiving, and later for nurturing the conceptus in the pre-embryonic stages, and stimulates feelings of love, desire, and paternal care in the male (this is the only time male oxytocin levels rival a female's). There is no correlation between testosterone and mena€™s perceptions of their orgasm experience, and also no correlation between higher testosterone levels and greater sexual assertiveness in either sex.
When testosterone-deprived rats were given medium levels of testosterone, their sexual behaviors (copulation, partner preference, etc.) resumed, but not when given low amounts of the same hormone. Some research has also indicated that if testosterone is eliminated in an adult male human or other adult male primate's system, its sexual motivation decreases, but there is no corresponding decrease in ability to engage in sexual activity (mounting, ejaculating, etc.). Men who have sexual encounters with unfamiliar or multiple partners experience large increases of testosterone the morning after.
Men who watch sexually explicit films also report increased optimism and decreased exhaustion. This result was seen in heterosexual men who had engaged in sexual activity in the 6 months prior to the study. Men who are exposed to scents of ovulating women maintained a stable testosterone level that was higher than the testosterone level of men exposed to nonovulation cues. It concluded that men with lower thresholds for sexual arousal have a greater likelihood to attend to sexual information and that testosterone may have an impact by enhancing their attention to the relevant stimuli.
This reaction engages penile reflexes (such as erection and ejaculation) that aid in sperm competition when more than one male is present in mating encounters, allowing for more production of successful sperm and a higher chance of reproduction.
Sexual thoughts also change the level of testosterone but not level of cortisol in the female body, and that hormonal contraceptives may have an impact on the variation in testosterone response to sexual thoughts. In addition, a continuous increase in vaginal sexual arousal may result in higher genital sensations and sexual appetitive behaviors. There is no current androgen preparation or for the treatment of androgen insufficiency approved by the FDA at this point in time, but it has been used off-label to treat low libido and sexual dysfunction in older women.
In humans, masculinization of the fetal brain appears, by observation of gender preference in patients with congenital diseases of androgen formation or androgen receptor function, to be associated with functional androgen receptors. Another study found a correlation between testosterone and risk tolerance in career choice among women.
Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimera€™s type, a key argument in life extension medicine for the use of testosterone in anti-aging therapies. Moreover, the conversion of testosterone to estradiol regulates male aggression in sparrows during breeding season.
Differences in sex hormones including testosterone have been suggested as an explanation for these differences. Appropriate use for this purpose is legitimate hormone replacement therapy (testosterone replacement therapy [TRT]), which maintains serum testosterone levels in the normal range.
Examples include reducing infertility, correcting lack of libido or erectile dysfunction, correcting osteoporosis, encouraging penile enlargement, encouraging height growth, encouraging bone marrow stimulation and reversing the effects of anemia, and even appetite stimulation.
Like-wise, transsexual women are sometimes prescribed anti-androgens to decrease the level of testosterone in the body and allow for the effects of estrogen to develop.
Adverse effects of testosterone supplementation include minor side effects such as acne and oily skin, and more significant complications such as increased hematocrit which can require venipuncture in order to treat, exacerbation of sleep apnea and acceleration of pre-existing prostate cancer growth in individuals who have undergone androgen deprivation.
Low testosterone also brings with it an increased risk for the development of Alzheimer's disease. There are several application methods for testosterone, including intramuscular injections, transdermal gels and patches, and implantable pellets. Forms of testosterone for human administration currently available include injectable (such as testosterone cypionate or testosterone enanthate in oil), oral, buccal, transdermal skin patches, transdermal creams, gels,[100] and implantable pellets.[101] Roll-on methods and nasal sprays are currently under development.
In the next step, two additional carbon atoms are removed by the CYP17A enzyme in the endoplasmic reticulum to yield a variety of C19 steroids.[103] In addition, the 3-hydroxyl group is oxidized by 3-I?-HSD to produce androstenedione. It is also synthesized in far smaller quantities in women by the thecal cells of the ovaries, by the placenta, as well as by the zona reticularis of the adrenal cortex and even skin[104] in both sexes. The number of Leydig cells in turn is regulated by luteinizing hormone (LH) and follicle stimulating hormone (FSH).
Approximately 0.3% of testosterone is converted into estradiol by aromatase (CYP19A1)[123] an enzyme expressed in the brain, liver, and adipose tissues. DHT binds to the same androgen receptor even more strongly than testosterone, so that its androgenic potency is about 5 times that of T.[127] The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. Greatly differing amounts of testosterone prenatally, at puberty, and throughout life account for a share of biological differences between males and females.
In the bones, estradiol accelerates ossification of cartilage into bone, leading to closure of the epiphyses and conclusion of growth.
Many of these analogs have an alkyl group introduced at the C-17 position in order to prevent conjugation and hence improve oral bioavailability. It may occur because of testicular dysfunction (primary hypogonadism) or hypothalamic-pituitary dysfunction (secondary hypogonadism) and may be congenital or acquired.[130] An acquired form of hypotestosteronism is a decline in testosterone levels that occurs by aging, sometimes being called "andropause" in men, as a comparison to the decline in estrogen that comes with menopause in women.
Koch, established easy access to a large source of bovine testiclesa€”the Chicago stockyardsa€”and to students willing to endure the ceaseless toil of extracting their isolates.


The period of the early 1930s to the 1950s has been called "The Golden Age of Steroid Chemistry",[141] and work during this period progressed quickly.
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The levels remain in a pubertal range for a few months, but usually reach the barely detectable levels of childhood by 4a€“6 months of age.
However, it is suggested that after the a€?honeymoon phasea€? ends, approximately 1a€“3 years into the relationship, this change in testosterone levels is no longer apparent. Therefore, these mammals may provide a model for studying clinical populations among humans suffering from sexual arousal deficits such as hypoactive sexual desire disorder. Previous research has found a link between relaxation following sexual arousal and testosterone levels. The increase in T levels was associated with the amount of a€?courtshipa€? behaviours that the men exhibited.
Testosterone levels and sexual arousal in men are heavily aware of hormone cycles in females. Testosterone may be a treatment for postmenopausal women as long as they are effectively estrogenized. One possible consequence of this could be an increased risk for the development of Alzheimera€™s disease.
A 2009 study found ethnical differences between blacks and whites in the testosterone to sex hormone binding globulin ratio in blood from the umbilical cord in infants. Women may also use testosterone therapies to treat or prevent loss of bone density, muscle mass and to treat certain kinds of depression and low energy state. A small trial in 2005 showed mixed results in using testosterone to combat the effects of aging.
Methyltestosterone and fluoxymesterone are no longer prescribed by physicians given their poor safety record, and testosterone replacement in men does have a very good safety record as evidenced by over sixty years of medical use in hypogonadal men. In some testing programs, an individual's own historical results may serve as a reference interval for interpretation of a suspicious finding. In the final and rate limiting step, the C-17 keto group androstenedione is reduced by 17-I? hydroxysteroid dehydrogenase to yield testosterone. In the testes, testosterone is produced by the Leydig cells.[105] The male generative glands also contain Sertoli cells which require testosterone for spermatogenesis. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects.
These are the so-called a€?17-aaa€? (17-alkyl androgen) family of androgens such as fluoxymesterone and methyltestosterone. Research in this golden age proved that this newly synthesized compounda€”testosteronea€”or rather family of compounds (for many derivatives were developed from 1940 to 1960), was a potent multiplier of muscle, strength, and well-being.
Fatherhood also decreases testosterone levels in men, suggesting that the resulting emotional and behavioral changes promote paternal care. This may be linked to the ovulatory shift hypothesis, where males are adapted to respond to the ovulation cycles of females by sensing when they are most fertile and whereby females look for preferred male mates when they are the most fertile; both actions may be driven by hormones. Decline of testosterone production with age has led to interest in androgen replacement therapy. Women on testosterone therapies may experience an increase in weight without an increase in body fat due to changes in bone and muscle density.
The American Society of Andrology's position is that "testosterone replacement therapy in aging men is indicated when both clinical symptoms and signs suggestive of androgen deficiency and decreased testosterone levels are present." The American Association of Clinical Endocrinologists says "Hypogonadism is defined as a free testosterone level that is below the lower limit of normal for young adult control subjects. Identification of inadequate testosterone in an aging male by symptoms alone can be difficult. This may be prevented with Propecia (Finasteride), which blocks DHT (a byproduct of testosterone in the body), during treatment. After a series of scandals and publicity in the 1980s (such as Ben Johnson's improved performance at the 1988 Summer Olympics), prohibitions of anabolic steroid use were renewed or strengthened by many sports organizations. Another approach being investigated is the detection of the administered form of testosterone, usually an ester, in hair. Like most hormones, testosterone is supplied to target tissues in the blood where much of it is transported bound to a specific plasma protein, sex hormone binding globulin (SHBG). It has been speculated that "brain masculinization" is occurring since no significant changes have been identified in other parts of the body. They also concluded that this response is related to the male's initial level of sexual arousal. The involvement in crime usually rises in the early teens to mid teens which happen at the same time as testosterone levels rise.
Most undesired effects of testosterone therapy in women may be controlled by hair-reduction strategies, acne prevention, etc. Exogenous testosterone also causes suppression of spermatogenesis and can lead to infertility.
Testosterone and other anabolic steroids were designated a "controlled substance" by the United States Congress in 1990, with the Anabolic Steroid Control Act. Surprisingly, the male brain is masculinized by testosterone being aromatized into estrogen, which crosses the blooda€“brain barrier and enters the male brain, whereas female fetuses have alpha-fetoprotein which binds up the estrogen so that female brains are not affected. Research on the relationship between testosterone and aggression is difficult since the only reliable measurement of brain testosterone is by a lumbar puncture which is not done for research purposes. There is a theoretical risk that testosterone therapy may increase the risk of breast or gynaecological cancers, and further research is needed to define any such risks more clearly.
It is recommended that physicians screen for prostate cancer with a digital rectal exam and PSA (prostate specific antigen) level before starting therapy, and monitor hematocrit and PSA levels closely during therapy. The use is seen as being a seriously problematic issue in modern sport, particularly given the lengths to which athletes and professional laboratories go to in trying to conceal such abuse from sports regulators. Studies therefore have often instead used more unreliable measurements from blood or saliva. Steroid abuse once again came into the spotlight recently as a result of the Chris Benoit double murder-suicide in 2007, and the media frenzy surrounding it a€“ however, there has been no evidence indicating steroid use as a contributing factor. Single men, who do not have relationship experience, have lower testosterone levels than single men with experience. Most studies support a link between adult criminality and testosterone although the relationship is modest if examined separately for each sex.
It is suggested that these single men with prior experience are in a more competitive state than their non-experienced counterparts. Most studies have also found testosterone to be associated with behaviors or personality traits linked with criminality such as antisocial behavior and alcoholism.
Collectively, these results suggest that it is the presence of competitive activities rather than bond-maintenance activities that are more relevant to changes in T levels.



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