In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6.[155] 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations.[155] The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism.[155] In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites.[155][156] Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.[155]

Keep in mind that you can use virtually any type of equipment you want for this – an elliptical machine, a treadmill, swimming, even sprinting outdoors (although you will need to do this very carefully to avoid injury) -- as long as you're pushing yourself as hard as you can for 30 seconds. But do be sure to stretch properly and start slowly to avoid injury. Start with two or three repetitions and work your way up, don't expect to do all eight repetitions the first time you try this, especially if you are out of shape.
That said, magnesium is one of a few ingredients demonstrated to impact testosterone levels. Researchers at Italy’s University of Palermo found that magnesium improved participants’ anabolic hormone status — including their testosterone levels. In a follow-up study, they confirm that even adjusting for age differences in their participant group, “magnesium was positively associated with total testosterone.” They propose that magnesium supplementation might help improve muscle performance in aging men — a group particularly vulnerable to declining/low testosterone levels. Outside of Italy, researchers at Turkey’s Selçuk University found that magnesium supplementation increased testosterone levels for both athletes and more sedentary men alike.
Take 1 teaspoon. Incredibly dense in nutrients and feed by bees to the larvae who grows on to be the queen bee. I found one human study where a 4g daily serving led to an small increase in testosterone in older men (ref 78). There are also numerous animal studies (ref 79) showing positive effects. Personally I source NZ manuka royal jelly from Manuka Health.
The largest amounts of testosterone (>95%) are produced by the testes in men,[2] while the adrenal glands account for most of the remainder. Testosterone is also synthesized in far smaller total quantities in women by the adrenal glands, thecal cells of the ovaries, and, during pregnancy, by the placenta.[126] In the testes, testosterone is produced by the Leydig cells.[127] The male generative glands also contain Sertoli cells, which require testosterone for spermatogenesis. 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).
Other Potential risks that can be caused by use of testosterone supplements are: People who take good testosterone supplements or any other kind of testosterone boosters can also experience many other side effects, including stomachache, problems with urination, dizziness, mood changes, intermittent breathing during sleep, changes in testicles, appetite loss, inflammation of gums, weight gain, nausea, painful erection, and protracted erection.
Any day that you don’t get 20 minutes of direct sunlight on your skin, you want to supplement with 5,000 IUs of vitamin D3. If you get your blood levels tested and you’re extremely low — below 50 IUs — you typically want to do 5,000 IUs twice a day for three months until you get those numbers up. You can do everything in the world, but if your vitamin D levels aren’t right, your testosterone levels will stay low.
The hypogonadal-obesity-adipocytokine cycle hypothesis. Adipose tissue contains the enzyme aromatase which metabolises testosterone to oestrogen. This results in reduced testosterone levels, which increase the action of lipoprotein lipase and increase fat mass, thus increasing aromatisation of testosterone and completing the cycle. Visceral fat also promotes lower testosterone levels by reducing pituitary LH pulse amplitude via leptin and/or other factors. In vitro studies have shown that leptin also inhibits testosterone production directly at the testes. Visceral adiposity could also provide the link between testosterone and insulin resistance (Jones 2007).
According to the Mayo Clinic, testosterone therapy can help treat hypogonadism. This condition occurs when the body can’t produce enough testosterone on its own. However, it’s unclear whether supplements can help. A study published in Nature Reviews Endocrinology found no scientific reason to prescribe testosterone to men over 65 years of age with normal or low to normal testosterone levels.
Testosterone was first used as a clinical drug as early as 1937, but with little understanding of its mechanisms. The hormone is now widely prescribed to men whose bodies naturally produce low levels. But the levels at which testosterone deficiency become medically relevant still aren’t well understood. Normal testosterone production varies widely in men, so it’s difficult to know what levels have medical significance. The hormone’s mechanisms of action are also unclear.

In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6.[155] 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations.[155] The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism.[155] In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites.[155][156] Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.[155]


Both men and women with Alzheimer’s Disease were found to have an increased concentration of SHBG and decreased free androgen index when compared with controls (Paoletti et al 2004). In a prospective study of 574 men whose baseline age span was 32–87 years and who were followed for a mean of 19.1 years (range, 4–37), the risk of developing Alzheimers’ Disease decreased 26 percent for each 10 unit increase in free testosterone index. The authors concluded that testosterone may be important for the prevention and treatment of AD (Moffat et al 2004).
The rise in testosterone levels during competition predicted aggression in males but not in females.[86] Subjects who interacted with hand guns and an experimental game showed rise in testosterone and aggression.[87] Natural selection might have evolved males to be more sensitive to competitive and status challenge situations and that the interacting roles of testosterone are the essential ingredient for aggressive behaviour in these situations.[88] Testosterone produces aggression by activating subcortical areas in the brain, which may also be inhibited or suppressed by social norms or familial situations while still manifesting in diverse intensities and ways through thoughts, anger, verbal aggression, competition, dominance and physical violence.[89] Testosterone mediates attraction to cruel and violent cues in men by promoting extended viewing of violent stimuli.[90] Testosterone specific structural brain characteristic can predict aggressive behaviour in individuals.[91]

Carbs play a big part in determining your Testosterone levels. Let's start with what to avoid. First, research shows that a large serving of sugar (75g of glucose), decreased Testosterone levels by as much as 25%! (25 & 26). I know this is a pretty extreme dosage, but you may want to avoid massive servings of sugar! Also, men who have Metabolic syndrome have lower Testosterone levels (27). Metabolic syndrome is often brought about by chronic high blood sugar which leads to insulin resistance.

Dr. Anthony's Notes: I like Tribulus. It is a VERY common herb in almost all testosterone boosting products – again though, it may be more of a libido enhancer than anything. From my personal experience, it's effective when stacked with the other libido enhancing supplements in this guide. How To Take Tribulus: Take 200-400mg once per day of a 45-60% saponin extract product.
Vitamin D deficiency is a growing epidemic in the US, and is profoundly affecting men’s health. The cholesterol-derived steroid hormone vitamin D is crucial for men’s health. It plays a role in the development of the sperm cell nucleus, and helps maintain semen quality and sperm count. Vitamin D can also increase your testosterone level, helping improve your libido. Have your vitamin D levels tested using a 25(OH)D or a 25-hydroxyvitamin D test. The optimal level of vitamin D is around 50 to 70 ng/ml for adults. There are three effective sources of vitamin D:

Mental status changes including excess aggression are a well known phenomenon in the context of anabolic steroid abuse (Perry et al 1990). An increase in self-reported aggressive behaviors have also been reported in one double blind placebo controlled trial of testosterone in young hypogonadal men (Finkelstein et al 1997), but this has not been confirmed in other studies (Skakkebaek et al 1981; O’Connor et al 2002). Aggression should therefore be monitored but in our experience is rarely a significant problem during testosterone replacement producing physiological levels.

This product is to be taken once daily on an empty stomach. Is there a particular time frame when food can be eaten? If I were to take this in the morning right when I wake up and then eat breakfast an hour later, is that fine? Also, mostly the only time of day my stomach is usually empty is right before going to bed. If it is taken at this time, will this affect sleep at all?

Testosterone is only one of many factors that influence aggression and the effects of previous experience and environmental stimuli have been found to correlate more strongly. A few studies indicate that the testosterone derivative estradiol (one form of estrogen) might play an important role in male aggression.[66][67][68][69] Studies have also found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus.[70]
Men who produce more testosterone are more likely to engage in extramarital sex.[55] Testosterone levels do not rely on physical presence of a partner; testosterone levels of men engaging in same-city and long-distance relationships are similar.[54] 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.[59]
A blood test may not be enough to determine your levels, because testosterone levels can fluctuate during the day. Once you determine that you do have low levels, there are a number of options to take. There are synthetic and bioidentical testosterone products out on the market, but I advise using bioidentical hormones like DHEA. DHEA is a hormone secreted by your adrenal glands. This substance is the most abundant precursor hormone in the human body. It is crucial for the creation of vital hormones, including testosterone and other sex hormones.

That there is an association between depression and testosterone concentration seems possible because of the observation that depression may be associated with reduced testosterone concentrations, hypogonadal men may have their symptoms of depression relieved by TRT and that testosterone itself may have anti-depressant properties (Pope et al 2003). The evidence, however, is inconsistent. Seidman and colleagues (2002), for example, found that there was no relationship between testosterone and depression but there was an association of testosterone with dysthymia. McIntyre and colleagues (2006), on the other hand, found that middle-aged men with depression did have a reduction in bio-available testosterone.

If testosterone deficiency occurs during fetal development, then male characteristics may not completely develop. If testosterone deficiency occurs during puberty, a boy’s growth may slow and no growth spurt will be seen. The child may have reduced development of pubic hair, growth of the penis and testes, and deepening of the voice. Around the time of puberty, boys with too little testosterone may also have less than normal strength and endurance, and their arms and legs may continue to grow out of proportion with the rest of their body.
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