Smith and colleagues (2005) undertook a prospective study on the contribution of stress to coronary heart disease. Their study, which involved 2512 men aged 45 to 59 years, looked at a number of metabolic parameters. They found that an increased cortisol to testosterone ratio was associated with a high risk of coronary artery disease and that this risk was mediated by components of the insulin resistance syndrome. They reported that high cortisol and low testosterone levels are associated with a worsening of insulin resistance and that there is evidence to support the possibility of improving this pattern by treatment with testosterone.
A related issue is the potential use of testosterone as a coronary vasodilator and anti-anginal agent. Testosterone has been shown to act as a vasodilator of coronary arteries at physiological concentrations during angiography (Webb, McNeill et al 1999). Furthermore men given a testosterone injection prior to exercise testing showed improved performance, as assessed by ST changes compared to placebo (Rosano et al 1999; Webb, Adamson et al 1999). Administration of one to three months of testosterone treatment has also been shown to improve symptoms of angina and exercise test performance (Wu and Weng 1993; English et al 2000; Malkin, Pugh, Morris et al 2004). Longer term studies are underway. It is thought that testosterone improves angina due its vasodilatory action, which occurs independently of the androgen receptor, via blockade of L-type calcium channels at the cell membrane of the vascular smooth muscle in an action similar to the dihydropyridine calcium-channel blockers such as nifedipine (Hall et al 2006).

Bhatia et al (2006) studied 70 male patients with type2 diabetes mellitus (age range 24–78 years). Thirty-seven subjects were found to have hypogonadism based on a calculated free testosterone level of less than 6.5 μg/dl. The hypogonadal group had a statistically significant lower hematocrit. Anemia was observed in 23% of the patients (16 out of 70). In 14 of 15 anemic patients calculated free testosterone was low.


Disclaimer: The entire contents of this website are based upon the opinions of Dr. Mercola, unless otherwise noted. Individual articles are based upon the opinions of the respective author, who retains copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of Dr. Mercola and his community. Dr. Mercola encourages you to make your own health care decisions based upon your research and in partnership with a qualified health care professional. If you are pregnant, nursing, taking medication, or have a medical condition, consult your health care professional before using products based on this content.
Men can experience a range of symptoms if testosterone decreases more than it should. Low testosterone, or low T, is diagnosed when levels fall below 300 nanograms per deciliter (ng/dL). A normal range is typically 300–1000 ng/dL, according to the U.S. Food and Drug Administration. A blood test called a serum testosterone test is used to determine your level of circulating testosterone.

It seems like today it’s a badge of honor to train every day until exhaustion. The ethos is to push yourself harder and harder every day. If that’s your philosophy towards exercise, you might be sabotaging your testosterone levels (as well as your 20 Mile March). Studies have shown that overtraining can reduce testosterone levels significantly. Yes, it’s important to exercise hard, but it’s even more important to give your body rest so it can recuperate from the damage you inflicted upon it.


For example, the study published in Obesity Research tells that the scientists measured testosterone levels in two groups of middle-aged men with obesity. One group underwent a 16-week weight loss program, while the second group did nothing. Each participant of the first group lost 20 kg on the average. And these participants experienced a significant increase in testosterone levels. So, the fight against overweight is very important for those who want to overcome testosterone deficiency. But starvation is strictly forbidden because this is a stressful situation which leads to the sharp decline in T levels.
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).
A loophole in FDA regulations allows pharmaceutical marketers to urge men to talk to their doctors if they have certain "possible signs" of testosterone deficiency. "Virtually everybody asks about this now because the direct-to-consumer marketing is so aggressive," says Dr. Michael O'Leary, a urologist at Harvard-affiliated Brigham and Women's Hospital. "Tons of men who would never have asked me about it before started to do so when they saw ads that say 'Do you feel tired?'"

I recommend using a trans-mucosal DHEA cream. Applying it to the rectum or if you are a a woman, your vagina, will allow the mucous epithelial membranes that line your mucosa to perform effective absorption. These membranes regulate absorption and inhibit the production of unwanted metabolites of DHEA. I personally apply 50 milligrams of trans-rectal DHEA cream twice a day – this has improved my own testosterone levels significantly. However, please note that I do NOT recommend prolonged supplementation of hormones. Doing so can trick your body into halting its own DHEA production and may cause your adrenals to become seriously impaired down.
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.
Binge drinking on the other hand does impact Testosterone levels – especially on a short term basis. Two studies (22 & 23) show that large acute quantities of alcohol consumption in a short period led to decreases in Testosterone levels by a whooping 20-23% after 24hours! Note however this is drinking to extreme excess! Likewise, chronic alcohol abuse is known to reduce testosterone more notably (as seen in alcoholics).
Attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans. Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimer's type,[100][101][102][103] a key argument in life extension medicine for the use of testosterone in anti-aging therapies. Much of the literature, however, suggests a curvilinear or even quadratic relationship between spatial performance and circulating testosterone,[104] where both hypo- and hypersecretion (deficient- and excessive-secretion) of circulating androgens have negative effects on cognition.
Bhatia et al (2006) studied 70 male patients with type2 diabetes mellitus (age range 24–78 years). Thirty-seven subjects were found to have hypogonadism based on a calculated free testosterone level of less than 6.5 μg/dl. The hypogonadal group had a statistically significant lower hematocrit. Anemia was observed in 23% of the patients (16 out of 70). In 14 of 15 anemic patients calculated free testosterone was low.
^ Jump up to: a b Lazaridis I, Charalampopoulos I, Alexaki VI, Avlonitis N, Pediaditakis I, Efstathopoulos P, Calogeropoulou T, Castanas E, Gravanis A (2011). "Neurosteroid dehydroepiandrosterone interacts with nerve growth factor (NGF) receptors, preventing neuronal apoptosis". PLoS Biol. 9 (4): e1001051. doi:10.1371/journal.pbio.1001051. PMC 3082517. PMID 21541365.
Early infancy androgen effects are the least understood. In the first weeks of life for male infants, testosterone levels rise. The levels remain in a pubertal range for a few months, but usually reach the barely detectable levels of childhood by 4–7 months of age.[15][16] The function of this rise in humans is unknown. It has been theorized that brain masculinization is occurring since no significant changes have been identified in other parts of the body.[17] The male brain is masculinized by the aromatization of testosterone into estrogen, which crosses the blood–brain barrier and enters the male brain, whereas female fetuses have α-fetoprotein, which binds the estrogen so that female brains are not affected.[18]

But when a premenopausal woman’s testosterone levels are too high, it can lead to polycystic ovary syndrome (PCOS), a condition that increases the risk of irregular or absent menstrual cycles, infertility, excess hair growth, skin problems, and miscarriage. High levels of testosterone in women, whether caused by PCOS or by another condition, can cause serious health conditions such as insulin resistance, diabetes, high cholesterol, high blood pressure, and heart disease. (12)
^ Mehta PH, Jones AC, Josephs RA (Jun 2008). "The social endocrinology of dominance: basal testosterone predicts cortisol changes and behavior following victory and defeat" (PDF). Journal of Personality and Social Psychology. 94 (6): 1078–93. CiteSeerX 10.1.1.336.2502. doi:10.1037/0022-3514.94.6.1078. PMID 18505319. Archived from the original (PDF) on April 19, 2009.
Do low levels of testosterone produce symptoms in middle-aged men? Absolutely. In fact, the classic symptoms were first recognized more than 70 years ago when two American physicians, Carl Heller, MD, and Gordon Myers, MD, showed the effectiveness of testosterone treatment for symptoms of fatigue, depression, irritability, low sex drive, erectile dysfunction, night sweats, and hot flashes in men. Over the years, subsequent studies have found that some—but not all—men with low, age-adjusted testosterone levels exhibit symptoms consistent with andropause. All experience improvement with testosterone therapy.

In many of the studies we found, those who saw the most improvement in health, testosterone, or muscle gain were those with existing nutrient or vitamin deficiencies. This means that some gains may be due more to dietary changes and generally restoring nutrient and vitamin levels than any one magic ingredient, but also that making sure your diet includes healthy amounts of nutrients should be your first step.


Sprinting has been shown numerous times that it has positive effects on testosterone levels. One 2011 study (ref 84) looked at weightlifters who performed 4x35m sprints twice a week. In contrast to the control group (who continued lifting but did not sprint), it was found that “After the 4-week training program, total testosterone and the total testosterone/cortisol ratio increased significantly in the (sprinters) EXP group”.
Men on long-term testosterone appear to have a higher risk of cardiovascular problems, like heart attacks, strokes, and deaths from heart disease. For example, in 2010, researchers halted the Testosterone in Older Men study when early results showed that men on hormone treatments had noticeably more heart problems. "In older men, theoretical cardiac side effects become a little more immediate," Dr. Pallais says.
×