Meat. Meat, particularly beef, provides our bodies with the protein it needs to create muscle (more muscle = more T) and the fats and cholesterol to make testosterone. My meat topping of choice was sliced up chuck steak. I grilled two of them on Monday and it lasted me until the next Monday. Every now and then I’d slow-cook some ribs or brisket to use as my meat topping. My philosophy was the fattier, the better.


A: There are no over-the-counter products approved by the U.S. Food and Drug Administration (FDA) to increase testosterone levels. There are several prescription medication options available. Please consult with your health care provider in regards to your testosterone levels and to determine which treatment option best meets your individual needs. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD

Longitudinal studies in male aging studies have shown that serum testosterone levels decline with age (Harman et al 2001; Feldman et al 2002). Total testosterone levels fall at an average of 1.6% per year whilst free and bioavailable levels fall by 2%–3% per year. The reduction in free and bioavailable testosterone levels is larger because aging is also associated with increases in SHBG levels (Feldman et al 2002). Cross-sectional data supports these trends but has usually shown smaller reductions in testosterone levels with aging (Feldman et al 2002). This is likely to reflect strict entry criteria to cross-sectional studies so that young healthy men are compared to older healthy men. During the course of longitudinal studies some men may develop pathologies which accentuate decreases in testosterone levels.

Testosterone is everywhere playing multiple roles from intrauterine life to advanced age. Table 1, the contents of which are always undergoing change primarily because of newly observed associations, provides an overview of the bodily systemic functions and patho-physiological states in which testosterone finds itself implicated. In some of these states there is a clear physiological cause and effect relationship. In others, evidence of the physiological role is early or tenuous.

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?'"


Individuals with metabolic syndrome are at increased risk for developing coronary artery disease and diabetes mellitus. Predicting who might develop the metabolic syndrome would allow preventive measures to be taken in addition to weight control and other lifestyle modifications such as cessation of smoking and increased exercise. It is known that with decreasing testosterone availability in aging males there is an increase in fat mass and decrease in lean body mass (van den Beld et al 2000), there are disorders of insulin and glucose metabolism (Haffner et al 1996) and dyslipidemia (Tsai et al 2004). Kupelian and colleagues (2006) in analyzing data from the Massachusetts Male Aging Study demonstrated that men with low levels of testosterone, sex hormone-binding globulin, or clinical androgen deficiency, especially men with a BMI of greater than 25, were at increased risk of developing the metabolic syndrome and hence, diabetes mellitus and/or coronary artery disease.
The science backs up the soldier’s self discovery, in fact, exposure to radiation (whether it’s from an army radar or the cell phone in your pocket, or the wifi router in your house) has been shown to lower sperm quality, fertility and testosterone. This is true not only for military personnel (88, 89,90) but all males living in a modern world (91).
A: According to the NIH, normal values for testosterone levels in men can range from 300 to 1,200ng/dL. There can be many different causes of low testosterone including age, diseases, accidents, and medications. Symptoms of low testosterone may include: loss of sex drive, erectile dysfunction, depressed mood, and difficulty concentrating. Low testosterone levels may also bring around body changes including: hair loss, decrease in blood cells possibly leading to anemia, fragile bones, and a decrease in muscle mass. There are different testosterone replacement therapies including patches, such as Androderm; gels, such as Androgel and Testim; and injections, such as testosterone cypionate. Only your health care provider can decide if and what kind of testosterone replacement therapy is appropriate for you. Testosterone replacement therapy is not right for everyone. Patient with certain prostate issues or breast cancer should not take testosterone. For more specific information, consult with your doctor for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD
Intramuscular testosterone injections were first used around fifty years ago. Commercially available preparations contain testosterone esters in an oily vehicle. Esterification is designed to retard the release of testosterone from the depot site into the blood because the half life of unmodified testosterone would be very short. For many years intramuscular preparations were the most commonly used testosterone therapy and this is still the case in some centers. Pain can occur at injection sites, but the injections are generally well tolerated and free of major side effects. Until recently, the available intramuscular injections were designed for use at a frequency of between weekly and once every four weeks. These preparations are the cheapest mode of testosterone treatment available, but often cause supraphysiological testosterone levels in the days immediately following injection and/or low trough levels prior to the next injection during which time the symptoms of hypogonadism may return (Nieschlag et al 1976). More recently, a commercial preparation of testosterone undecanoate for intramuscular injection has become available. This has a much longer half life and produces testosterone levels in the physiological range throughout each treatment cycle (Schubert et al 2004). The usual dose frequency is once every three months. This is much more convenient for patients but does not allow prompt cessation of treatment if a contraindication to testosterone develops. The most common example of this would be prostate cancer and it has therefore been suggested that shorter acting testosterone preparations should preferably used for treating older patients (Nieschlag et al 2005). Similar considerations apply to the use of subcutaneous implants which take the form of cylindrical pellets injected under the skin of the abdominal wall and steadily release testosterone to provide physiological testosterone levels for up to six months. Problems also include pellet extrusion and infection (Handelsman et al 1997).
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)".[180] They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The structure was worked out by Schering's Adolf Butenandt, at the Chemisches Institut of Technical University in Gdańsk.[181][182]
Vitamin D is a fat-soluble vitamin and is obtained from sunlight. In the active form, it acts as a steroid hormone in the body. These days many people suffer from vitamin D deficiency because lacking exposure to sunlight, but taking vitamin D supplements to improve the weakness. Low vitamin D levels also lower the testosterone levels, but with intake of vitamin D, the testosterone levels boost. In typical cases, vitamin D doesn’t show the significant result in testosterone levels but people who are vitamin D deficient shows an increase in testosterone levels.
We do note that Beast Sports’ supplemental magnesium level is fairly low — 26 mg per serving, up to 52 mg per day. If your diet is not particularly rich in magnesium (found in leafy greens, nuts, and whole grains), Beast Sports may not give you enough to meet the daily recommended dose. However, if you’re taking other multi-vitamins or supplements with magnesium, you’re less likely to cross that 350mg daily upper limit.
Both testosterone and 5α-DHT are metabolized mainly in the liver.[1][151] Approximately 50% of testosterone is metabolized via conjugation into testosterone glucuronide and to a lesser extent testosterone sulfate by glucuronosyltransferases and sulfotransferases, respectively.[1] An additional 40% of testosterone is metabolized in equal proportions into the 17-ketosteroids androsterone and etiocholanolone via the combined actions of 5α- and 5β-reductases, 3α-hydroxysteroid dehydrogenase, and 17β-HSD, in that order.[1][151][152] Androsterone and etiocholanolone are then glucuronidated and to a lesser extent sulfated similarly to testosterone.[1][151] The conjugates of testosterone and its hepatic metabolites are released from the liver into circulation and excreted in the urine and bile.[1][151][152] Only a small fraction (2%) of testosterone is excreted unchanged in the urine.[151]

Overall, it seems that both estrogen and testosterone are important for normal bone growth and maintenance. Deficiency or failure of action of the sex hormones is associated with osteoporosis and minimal trauma fractures. Estrogen in males is produced via metabolism of testosterone by aromatase and it is therefore important that androgens used for the treatment of hypogonadism be amenable to the action of aromatase to yield maximal positive effects on bone. There is data showing that testosterone treatment increases bone mineral density in aging males but that these benefits are confined to hypogonadal men. The magnitude of this improvement is greater in the spine than in the hip and further studies are warranted to confirm or refute any differential effects of testosterone at these important sites. Improvements seen in randomized controlled trials to date may underestimate true positive effects due to relatively short duration and/or baseline characteristics of the patients involved. There is no data as yet to confirm that the improvement in bone density with testosterone treatment reduces fractures in men and this is an important area for future study.
We scoured the database of the National Center for Biotechnology Information (part of the U.S. National Library of Science) for articles. Of the many ingredients marketed as boosting testosterone levels, we only found four backed by multiple articles based on human testing. For the best chance of boosting testosterone levels, a supplement needs to contain magnesium, fenugreek, and longjack — and some zinc wouldn’t go astray, either.
A: Androderm comes in the form of a transdermal patch and is used for testosterone replacement therapy in patients who have insufficient levels of testosterone. Testosterone is a hormone produced in the body that plays a key role in many physiological processes in men. In some men, however, the body does not produce enough of the hormone, resulting in a variety of symptoms including decreased libido, erectile dysfunction, muscle loss, anemia and depression, among others. Androderm helps treat these symptoms and raise low testosterone levels by delivering therapeutic amounts of the hormone, which are absorbed through the skin. According to the prescribing information for Androderm, depression was a reported side effect of the medication. Other common side effects of Androderm include itching and redness at the application site, prostate abnormalities, headache, and burning or hardening of the skin at the application site. Less common side effects of Androderm include reduced libido (sex drive), fatigue, high blood pressure, anxiety, confusion, increased appetite, and body pain. For more specific information, consult with your doctor for guidance based on your health status and current medications, particularly before taking any action. Your physician can determine if your dosage of the medication needs to be adjusted or if an alternative medication should be considered. Lori Poulin, PharmD

Osteoporosis refers to pathological loss of bone density and strength. It is an important condition due to its prevalence and association with bone fractures; most commonly of the hip, vertebra and forearm. Men are relatively protected from the development of osteoporosis by a higher peak bone mass compared with women (Campion and Maricic 2003). Furthermore, women lose bone at an accelerated rate immediately following the menopause. Nevertheless, men start to lose bone mass during early adult life and experience an increase in the rate of bone loss with age (Scopacasa et al 2002). Women of a given age have a higher prevalence of osteoporosis in comparison to men but the prevalence increases with age in both sexes. As a result, men have a lower incidence of osteoporotic fractures than women of a given age but the gap between the sexes narrows with advancing age (Chang et al 2004) and there is evidence that hip fractures in men are associated with greater mortality than in women (Campion and Maricic 2003).


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.
Ghlissi, Z., Atheymen, R., Boujbiha, M. A., Sahnoun, Z., Makni Ayedi, F., Zeghal, K., ... Hakim, A. (2013, December). Antioxidant and androgenic effects of dietary ginger on reproductive function of male diabetic rats [Abstract]. International Journal of Food Sciences and Nutrition, 64 (8), 974–978. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23862759
Currently available testosterone preparations in common use include intramuscular injections, subcutaneous pellets, buccal tablets, transdermal gels and patches (see Table 2). Oral testosterone is not widely used. Unmodified testosterone taken orally is largely subject to first-pass metabolism by the liver. Oral doses 100 fold greater than physiological testosterone production can be given to achieve adequate serum levels. Methyl testosterone esters have been associated with hepatotoxicity. There has been some use of testosterone undecanoate, which is an esterified derivative of testosterone that is absorbed via the lymphatic system and bypasses the liver. Unfortunately, it produces unpredictable testosterone levels and increases testosterone levels for only a short period after each oral dose (Schurmeyer et al 1983).
Testosterone is included in the World Health Organization's list of essential medicines, which are the most important medications needed in a basic health system.[107] It is available as a generic medication.[10] The price depends on the form of testosterone used.[108] It can be administered as a cream or transdermal patch that is applied to the skin, by injection into a muscle, as a tablet that is placed in the cheek, or by ingestion.[10]
Testosterone makes a contribution to nitric oxide formation. Nitric oxide, released from penile nerves stimulates guanylate cyclase which catalyzes the transformation of guanosine-5-triphosphate into 3′,5′-cyclic, guanosine monophosphate (cyclic GMP). Gyclic GMP causes vasodilatation and hence erection formation (Morelli et al 2005). The breakdown of cyclic GMP to GMP is mediated by the enzyme, phosphodiesterase type-5, the inhibitors of which (eg, sildenafil citrate) enhance erection formation and maintanence (Carson and Lue 2005).

However, testosterone is only one of many factors that aid in adequate erections. Research is inconclusive regarding the role of testosterone replacement in the treatment of erectile dysfunction. In a review of studies that looked at the benefit of testosterone in men with erection difficulties, showed no improvement with testosterone treatment. Many times, other health problems play a role in erectile difficulties. These can include:
Ginger has been used as medicine for centuries due to its potent antioxidant potential. It also exhibits anti-inflammatory properties which makes it best for natural therapeutics. It improves the sexual function and testosterone levels by stimulating the luteinizing hormone. It also enhances the sperm count, which makes it useful to solve infertility issues.
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Ashwagandha is sometimes included in testosterone supplements because of the hypothesis that it improves fertility. However, we couldn’t find sufficient evidence to support this claim (at best, one study found that ashwagandha might improve cardiorespiratory endurance). WebMD advocates caution when taking this herb, as it may interact with immunosuppressants, sedative medications, and thyroid hormone medications.
In 1927, the University of Chicago's Professor of Physiologic Chemistry, Fred C. Koch, established easy access to a large source of bovine testicles — the Chicago stockyards — and recruited students willing to endure the tedious work of extracting their isolates. In that year, Koch and his student, Lemuel McGee, derived 20 mg of a substance from a supply of 40 pounds of bovine testicles that, when administered to castrated roosters, pigs and rats, remasculinized them.[179] The group of Ernst Laqueur at the University of Amsterdam purified testosterone from bovine testicles in a similar manner in 1934, but isolation of the hormone from animal tissues in amounts permitting serious study in humans was not feasible until three European pharmaceutical giants—Schering (Berlin, Germany), Organon (Oss, Netherlands) and Ciba (Basel, Switzerland)—began full-scale steroid research and development programs in the 1930s.
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:
The reliable measurement of serum free testosterone requires equilibrium dialysis. This is not appropriate for clinical use as it is very time consuming and therefore expensive. The amount of bioavailable testosterone can be measured as a percentage of the total testosterone after precipitation of the SHBG bound fraction using ammonium sulphate. The bioavailable testosterone is then calculated from the total testosterone level. This method has an excellent correlation with free testosterone (Tremblay and Dube 1974) but is not widely available for clinical use. In most clinical situations the available tests are total testosterone and SHBG which are both easily and reliably measured. Total testosterone is appropriate for the diagnosis of overt male hypogonadism where testosterone levels are very low and also in excluding hypogonadism in patients with normal/high-normal testosterone levels. With increasing age, a greater number of men have total testosterone levels just below the normal range or in the low-normal range. In these patients total testosterone can be an unreliable indicator of hypogonadal status. There are a number of formulae that calculate an estimated bioavailable or free testosterone level using the SHBG and total testosterone levels. Some of these have been shown to correlate well with laboratory measures and there is evidence that they more reliably indicate hypogonadism than total testosterone in cases of borderline biochemical hypogonadism (Vermeulen et al 1971; Morris et al 2004). It is important that such tests are validated for use in patient populations relevant to the patient under consideration.
Cardiovascular disease, and its underlying pathological process atherosclerosis, is an important cause of morbidity and mortality in the developed and developing world. Coronary heart disease in particular is the commonest cause of death worldwide (AHA 2002; MacKay and Mensah 2004). As well as increasing with age, this disease is more common in the male versus female population internationally, which has led to interest in the potential role of sex hormones in modulating risk of development of atherosclerosis. Concerns about the potential adverse effects of testosterone treatment on cardiovascular disease have previously contributed to caution in prescribing testosterone to those who have, or who are at risk of, cardiovascular disease. Contrary to fears of the potential adverse effects of testosterone on cardiovascular disease, there are over forty epidemiological studies which have examined the relationship of testosterone levels to the presence or development of coronary heart disease, and none have shown a positive correlation. Many of these studies have found the presence of coronary heart disease to be associated with low testosterone levels (Reviews: Jones, Jones et al 2003; Jones et al 2005).
Does zinc provide testosterone benefits? The answer is, yes. It is an essential mineral which is used in many processes within the body and has a similar role like vitamin D. Men who have a deficiency of zinc may suffer from low testosterone levels but taking zinc supplements can help them to improve the testosterone levels. Zinc deficiency is an essential factor in infertility because it also reduces the sperm count, but with supplements, the sperm count increases along with improvement in testosterone levels. It also helps to recover from high-intensity interval training because that also cause the decline in testosterone levels.
A: Androderm comes in the form of a transdermal patch and is used for testosterone replacement therapy in patients who have insufficient levels of testosterone. Testosterone is a hormone produced in the body that plays a key role in many physiological processes in men. In some men, however, the body does not produce enough of the hormone, resulting in a variety of symptoms including decreased libido, erectile dysfunction, muscle loss, anemia and depression, among others. Androderm helps treat these symptoms and raise low testosterone levels by delivering therapeutic amounts of the hormone, which are absorbed through the skin. According to the prescribing information for Androderm, depression was a reported side effect of the medication. Other common side effects of Androderm include itching and redness at the application site, prostate abnormalities, headache, and burning or hardening of the skin at the application site. Less common side effects of Androderm include reduced libido (sex drive), fatigue, high blood pressure, anxiety, confusion, increased appetite, and body pain. For more specific information, consult with your doctor for guidance based on your health status and current medications, particularly before taking any action. Your physician can determine if your dosage of the medication needs to be adjusted or if an alternative medication should be considered. Lori Poulin, PharmD
Now that we know chronic insulin spikes lead to lower Testosterone production, I hope I haven’t sent you running into the low carb camp! There are a few studies out there showing that long term low carb or ketogenic dieting leads to higher cortisol levels (especially with subjects who are training), and decreased testosterone levels (28 & 29). I have used low carb diets in the past with successful results (winning a national bodybuilding title), however the key is to use cyclical carb re-feeds. If you’re going to go on a low carb diet for whatever reason, be sure to work in a large carb reefed once a week.
Dr. Anthony’s Notes: Vitamin D has about 100 other beneficial body functions outside of it's impact on testosterone. Make sure you take the active Vitamin D3 (not D2 – from plant sources!) It’s also advisable to get 20 minutes of sunshine daily (weather permitting) – without sunscreen. Verdict: this is one of the natural testosterone supplements that work. Best Food Sources of Vitamin D3: Wild Alaskan Salmon (#1), Sardines, Eggs How To Take Vitamin D3: Using 3000-5000IU of Vitamin D3 per day is a good safe, research supported dose. Your physician can also test your blood for D3 levels for more precise monitoring.
In addition to weight training, combining this with interval training like burst training is the best overall combo to increase HGH. In fact, Burst training has been proven to not only boost T-levels, it helps keeps your testosterone elevated and can prevent its decline. Burst training involves exercising at 90–100 percent of your maximum effort for a short interval in order to burn your body’s stored sugar (glycogen), followed by a period of low impact for recovery.
This content is strictly the opinion of Dr. Josh Axe and is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of medical advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Axe nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement or lifestyle program.
For this reason I recommend doing your own research on this supplement before taking it. 5g of ground up dried powder is what was used in the studies. I recommend taking 1-2 capsules of the concentrated form from Paradise Herbs. Alternatively, the Aggressive Strength Test Booster also has MP in its formula so you may prefer to use that blend instead. 
Acne and Allergic Reactions: The testosterone is universally regarded as one of the triggering factors for acne. It stimulates the activity of oil glands making the skin more oily and vulnerable to acne. This body hormone might also cause allergic reactions, such as hives, rash, difficulty breathing, itching, chest tightness, and big swelling of the facial parts.
Longjack, also known as Tongkat ali and pasak bumi, is a shrub hailing from Southeast Asia purporting to improve libido. It’s gaining traction in the scientific community for potentially increasing testosterone levels, and researchers at South Africa’s University of the Western Cape found that longjack improved testosterone levels and muscular strength in physically active seniors (a population with typically low testosterone).
The prevalence of biochemical testosterone deficiency increases with age. This is partly due to decreasing testosterone levels associated with illness or debility but there is also convincing epidemiological data to show that serum free and total testosterone levels also fall with normal aging (Harman et al 2001; Feldman et al 2002). The symptoms of aging include tiredness, lack of energy, reduced strength, frailty, loss of libido, decreased sexual performance depression and mood change. Men with hypogonadism experience similar symptoms. This raises the question of whether some symptoms of aging could be due to relative androgen deficiency. On the other hand, similarities between normal aging and the symptoms of mild androgen deficiency make the clinical diagnosis of hypogonadism in aging men more challenging.
Unlike women, who experience a rapid drop in hormone levels at menopause, men experience a more gradual decrease of testosterone levels over time. The older the man, the more likely he is to experience below-normal testosterone levels. Men with testosterone levels below 300 ng/dL may experience some degree of low T symptoms. Your doctor can conduct a blood test and recommend treatment if needed. They can discuss the potential benefits and risks of testosterone medication, as well.
Testosterone booster products obtained from trusted sources and administered as per the recommendations of the manufacturer may still present some health risks. The present case provided weak evidence of causality between acute liver injury and a commercial testosterone booster. To guarantee an optimal outcome with no severe side effects, further research is warranted to confirm the present findings and determine whether the effects observed in this case report would be statistically significant in larger samples.
Does the diminution that age brings with it in both total and bioavailable T have any clinical significance? This question leads us to the theme of this paper, “The Many Faces of Testosterone”. If testosterone were simply a “sex hormone” involved only with sexual desire and arousal we might tend to dismiss testosterone treatment in the aging man as merely a “life-style” therapy without any substantive basis for broad physiological necessity. The fact is, however, that the sexual attributes of testosterone are the least of its physiological necessities and that testosterone has a broad spectrum of demonstrated physiological functions as well as a wide variety of physiological and pathophysiological associations about which we are just learning.
The production of the stress hormone cortisol blocks the production and effects of testosterone. From a biological perspective, cortisol increases your “fight or flight” response, thereby lowering testosterone-associated functions such as mating, competing, and aggression. Chronic stress can take a toll on testosterone production, as well as your overall health. Therefore, stress management is equally important to a healthy diet and regular exercise. Tools you can use to stay stress-free include prayer, meditation, laughter, and yoga. Relaxation skills, such as deep breathing and visualization, can also promote your emotional health.
^ 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.
Ten healthy men aged around 24 years old spent 1 week sleeping for 8 hours per night at home, they then spent the next 11 nights in a lab. They slept for 10 hours per night for 3 nights, followed by 8 nights of restricted sleep, when they slept for only 5 hours. Doctors checked their blood every 15 to 30 minutes during the last night that they slept 10 hours, as well as on the sleep-restricted session.

A number of epidemiological studies have found that bone mineral density in the aging male population is positively associated with endogenous androgen levels (Murphy et al 1993; Ongphiphadhanakul et al 1995; Rucker et al 2004). Testosterone levels in young men have been shown to correlate with bone size, indicating a role in determination of peak bone mass and protection from future osteoporosis (Lorentzon et al 2005). Male hypogonadism has been shown to be a risk factor for hip fracture (Jackson et al 1992) and a recent study showed a high prevalence of hypogonadism in a group of male patients with average age 75 years presenting with minimal trauma fractures compared to stroke victims who acted as controls (Leifke et al 2005). Estrogen is a well known determinant of bone density in women and some investigators have found serum estrogen to be a strong determinant of male bone density (Khosla et al 1998; Khosla et al 2001). Serum estrogen was also found to correlate better than testosterone with peak bone mass (Khosla et al 2001) but this is in contradiction of a more recent study showing a negative correlation of estrogen with peak bone size (Lorentzon et al 2005). Men with aromatase deficiency (Carani et al 1997) or defunctioning estrogen receptor mutations (Smith et al 1994) have been found to have abnormally low bone density despite normal or high testosterone levels which further emphasizes the important influence of estrogen on male bone density.


The researchers found that the dose of testosterone required to produce different effects in the body varied widely. The influence of testosterone and estradiol also differed. As the testosterone gel dose was reduced, the scientists showed, reductions in lean mass, muscle size, and leg-press strength resulted from decreases in testosterone itself. In contrast, increases in body fat were due to the related declines in estradiol. Both testosterone and estradiol levels were associated with libido and erectile function.
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