Erectile dysfunction or disorder (ED) is the inability to develop and maintain an erection for satisfactory sexual intercourse or activity. Erectile dysfunction or erectile disorder are the preferred terms as opposed to impotence. There are no uniform criteria defining how consistent the problem has to be and for what duration it must be present to considered ED. The Diagnostic and Statistical Manual of Mental Disorder-5 specifies a duration of at least 6 months in its definition of ED.1
Many clinical studies have looked at the effect of testosterone treatment on body composition in hypogonadal men or men with borderline low testosterone levels. Some of these studies specifically examine these changes in older men (Tenover 1992; Morley et al 1993; Urban et al 1995; Sih et al 1997; Snyder et al 1999; Kenny et al 2001; Ferrando et al 2002; Steidle et al 2003; Page et al 2005). The data from studies, on patients from all age groups, are consistent in showing an increase in fat free mass and decrease in fat mass or visceral adiposity with testosterone treatment. A recent meta-analysis of 16 randomized controlled trials of testosterone treatment effects on body composition confirms this pattern (Isidori et al 2005). There have been less consistent results with regard to the effects of testosterone treatment of muscle strength. Some studies have shown an increase in muscle strength (Ferrando et al 2002; Page et al 2005) with testosterone whilst others have not (Snyder et al 1999). Within the same trial some muscle group strengths may improve whilst others do not (Ly et al 2001). It is likely that the differences are partly due to the methodological variations in assessing strength, but it also possible that testosterone has different effects on the various muscle groups. The meta-analysis found trends toward significant improvements in dominant knee and hand grip strength only (Isidori et al 2005).
Dr. Ronald Swerdloff, chief of the endocrinology division at the Harbor-UCLA Medical Center and a professor of medicine at UCLA's David Geffen School of Medicine, served on the panel of experts who developed the Endocrine Society's guidelines. He is also the principal investigator for one of the 12 sites of The Testosterone Trial in Older Men, a nationwide study funded mainly by the National Institute on Aging. The study of 800 men over age 65 with low testosterone is looking at whether men using AndroGel for one year, compared to placebo, will show improvements in walking speed, sexual activity, vitality, memory, and anemia. The study will be completed in June 2015.

Testosterone replacement therapy may improve energy, mood, and bone density, increase muscle mass and weight, and heighten sexual interest in older men who may have deficient levels of testosterone. Testosterone supplementation is not recommended for men who have normal testosterone levels for their age group due to the risk of prostate enlargement and other side effects. Testosterone replacement therapy is available as a cream or gel, topical solution, skin patch, injectable form and pellet form placed under the skin.


Falling in love decreases men's testosterone levels while increasing women's testosterone levels. There has been speculation that these changes in testosterone result in the temporary reduction of differences in behavior between the sexes.[53] However, it is suggested that after the "honeymoon phase" ends—about four years into a relationship—this change in testosterone levels is no longer apparent.[53] Men who produce less testosterone are more likely to be in a relationship[54] or married,[55] and men who produce more testosterone are more likely to divorce;[55] however, causality cannot be determined in this correlation. Marriage or commitment could cause a decrease in testosterone levels.[56] Single men who have not had relationship experience have lower testosterone levels than single men with experience. It is suggested that these single men with prior experience are in a more competitive state than their non-experienced counterparts.[57] Married men who engage in bond-maintenance activities such as spending the day with their spouse/and or child have no different testosterone levels compared to times when they do not engage in such activities. Collectively, these results suggest that the presence of competitive activities rather than bond-maintenance activities are more relevant to changes in testosterone levels.[58]
Capogrosso, P., Colicchia, M., Ventimiglia, E., Castagna, G., Clementi, M. C., Suardi, N., ... Salonia, A. (2013, July). One patient out of four with newly diagnosed erectile dysfunction is a young man — worrisome picture from the everyday clinical practice. The journal of sexual medicine. 10(7), 1833–1841. Retrieved from https://onlinelibrary.wiley.com/doi/full/10.1111/jsm.12179
Testosterone is most commonly associated with sex drive in men. It also affects mental health, bone and muscle mass, fat storage, and red blood cell production. Abnormally low or high levels can affect a man’s mental and physical health. Your doctor can check your testosterone levels with a simple blood test. Testosterone therapy is available to treat men with low levels of testosterone. If you have low T, ask your doctor if this type of therapy might benefit you.
Impotence is a common problem among men and is characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Erectile dysfunction can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent ability to do so, or a tendency to sustain only very brief erections.

All devices that are currently approved by the FDA are considered safe for use in magnetic resonance imaging environments. However, 2 previously approved devices–the OmniPhase and the DuraPhase penile prostheses–are not considered safe in this environment. Other surgical procedures–including venous ligation to limit penile venous outflow and penile revascularization procedures–are rarely successful and are not recommended.19 These surgeries are only indicated when a patient demonstrates recent-onset ED and an occlusive lesion seen on angiogram or magnetic resonance angiography and should be performed only in centers of excellence for ED.


Vitamin D and zinc are both essential to testosterone production. A year-long study looked at the vitamin D and testosterone levels of 2299 men. It found that men with vitamin D levels above 30 nmol/L had more testosterone and lower levels of sex hormone-binding globulin (SHBG). SHBG binds to hormones so your cells can’t use them, and if you have too much of it, your testosterone levels drop [8]. Men with vitamin D deficiency had lower testosterone and higher SHBG levels.
If PDE5 drugs don't work or cannot be used because of potential side effects, your doctor can recommend other therapies. The drug alprostadil (Caverject, Edex, Muse) allows blood to flow more freely in the penis, leading to an erection. The drug can be injected with a tiny needle into your penis. Or, a small pellet (suppository) can be inserted into the opening of the penis. Suppositories and injections are effective in the majority of men.
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.
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]
Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. 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. Therefore, these mammals may provide a model for studying clinical populations among humans suffering from sexual arousal deficits such as hypoactive sexual desire disorder.[37]
Sugar is to testosterone what kryptonite is to Superman. Eliminating sugar is probably the single most powerful way to increase your performance, in part because sugar absolutely devastates your testosterone levels (but all carbs do not, especially under heavy training.) In one study of 74 men, a 75g dose of sugar – about the equivalent of a bottle of soda – decreased serum testosterone by 25% in under an hour, and levels stayed low for at least 2 hours [7]. On top of that, 15% of the men who started with normal testosterone dipped into the hypogonadal range after they ate sugar – that’s the range in which doctors diagnose men’s testes and women’s ovaries as failing. When you do eat carbs, stick to Bulletproof ones like sweet potatoes and squash. My recommendations for types of carbs and how often to eat them are here.
What you need to know about delayed ejaculation Delayed ejaculation is a sexual disorder that can be distressing for a man and his partner and may disrupt a relationship. There are many reasons why delayed ejaculation occurs, including tissue damage, age, drugs, and the side effects of medication. They may be physiological or psychological. Find out how to get help. Read now

The physical side effects of chemotherapy are usually temporary and resolve within one to two weeks after stopping the chemotherapy. However, chemotherapy agents, such as Ciplatin or Vincristine, may interfere with the nerves that control erection leading to possible impotence. Make sure you discuss potential side effects of cancer chemotherapy with your doctor or healthcare provider.
Hormone deficiency or hypogonadism, whether primary or secondary, has been thought to impact erectile function. Approximately a third of men in the European Male Aging Study demonstrated low testosterone, suggesting that hypogonadism is overrepresented among men with ED.11 Hormone deficiency, however, is less frequently the cause of ED than diabetes or vascular disease. Many entities with a strong relationship to ED also diminish bioavailable testosterone, including obesity, diabetes, and opioid use. Other hormones involved in testosterone metabolism or availability, like thyroid stimulating hormone and gonadotropins, also may impact erectile quality, presumably through regulating bioavailable testosterone. Understanding the relationship between testosterone and ED has been impaired by a lack of standardized measurement of this hormone and the cyclic nature of its release and consumption. 

The hormone also plays a role in sex drive, sperm production, fat distribution, red cell production, and maintenance of muscle strength and mass, according to the Mayo Clinic. For these reasons, testosterone is associated with overall health and well-being in men. One 2008 study published in the journal Frontiers of Hormone Research even linked testosterone to the prevention of osteoporosis in men.
In a randomized double-blind, parallel, placebo-controlled trial, sildenafil plus testosterone was not superior to sildenafil plus placebo in improving erectile function in men with ED and low testosterone levels. [19] The objective of the study was to determine whether the addition of testosterone to sildenafil therapy improves erectile response in men with ED and low testosterone levels.
Findings that improvements in serum glucose, serum insulin, insulin resistance or glycemic control, in men treated with testosterone are accompanied by reduced measures of central obesity, are in line with other studies showing a specific effect of testosterone in reducing central or visceral obesity (Rebuffe-Scrive et al 1991; Marin, Holmang et al 1992). Furthermore, studies that have shown neutral effects of testosterone on glucose metabolism have not measured (Corrales et al 2004), or shown neutral effects (Lee et al 2005) (Tripathy et al 1998; Bhasin et al 2005) on central obesity. Given the known association of visceral obesity with insulin resistance, it is possible that testosterone treatment of hypogonadal men acts to improve insulin resistance and diabetes through an effect in reducing central obesity. This effect can be explained by the action of testosterone in inhibiting lipoprotein lipase and thereby reducing triglyceride uptake into adipocytes (Sorva et al 1988), an action which seems to occur preferentially in visceral fat (Marin et al 1995; Marin et al 1996). Visceral fat is thought to be more responsive to hormonal changes due to a greater concentration of androgen receptors and increased vascularity compared with subcutaneous fat (Bjorntorp 1996). Further explanation of the links between hypogonadism and obesity is offered by the hypogonadal-obesity-adipocytokine cycle hypothesis (see Figure 1). In this model, increases in body fat lead to increases in aromatase levels, in addition to insulin resistance, adverse lipid profiles and increased leptin levels. Increased action of aromatase in metabolizing testosterone to estrogen, reduces testosterone levels which induces further accumulation of visceral fat. Higher leptin levels and possibly other factors, act at the pituitary to suppress gonadotrophin release and exacerbate hypogonadism (Cohen 1999; Kapoor et al 2005). Leptin has also been shown to reduce testosterone secretion from rodent testes in vitro (Tena-Sempere et al 1999). A full review of the relationship between testosterone, insulin resistance and diabetes can be found elsewhere (Kapoor et al 2005; Jones 2007).
^ Butenandt A, Hanisch G (1935). "Uber die Umwandlung des Dehydroandrosterons in Androstenol-(17)-one-(3) (Testosterone); um Weg zur Darstellung des Testosterons auf Cholesterin (Vorlauf Mitteilung). [The conversion of dehydroandrosterone into androstenol-(17)-one-3 (testosterone); a method for the production of testosterone from cholesterol (preliminary communication)]". Chemische Berichte (in German). 68 (9): 1859–62. doi:10.1002/cber.19350680937.
The other interesting thing about the study: men’s testosterone levels were lowest in March (at the end of winter) and highest in August (at the end of summer). Sunlight affects your vitamin D production, so you have seasonal dips and peaks. Get a blood test to check your levels, and if you’re low, take a high-quality vitamin D3 supplement. If you’re going to take D3, take vitamin K2 and vitamin A with it. The three work in sync, so you want them all to be balanced. Here are my dosage recommendations.
Clinical studies have suggested that these devices are effective and acceptable to a large number of patients with ED of varying causes, including psychogenic erectile failure. These devices are safe and can restore a man’s ability to achieve penetrative intercourse, with one study suggesting nearly 95% success with adequate instruction and support.30 However, satisfaction with this treatment modality typically wanes with time, as patients report dissatisfaction with how cumbersome or unnatural the devices are to use, hinging or buckling of the erection with thrusting, and dissatisfaction with the fact that the erection is ischemic and therefore cold, which can be off-putting to the partner.
Fatherhood decreases testosterone levels in men, suggesting that the emotions and behavior tied to decreased testosterone promote paternal care. In humans and other species that utilize allomaternal care, paternal investment in offspring is beneficial to said offspring's survival because it allows the parental dyad to raise multiple children simultaneously. This increases the reproductive fitness of the parents, because their offspring are more likely to survive and reproduce. Paternal care increases offspring survival due to increased access to higher quality food and reduced physical and immunological threats.[60] This is particularly beneficial for humans since offspring are dependent on parents for extended periods of time and mothers have relatively short inter-birth intervals,[61] While extent of paternal care varies between cultures, higher investment in direct child care has been seen to be correlated with lower average testosterone levels[62] as well as temporary fluctuations. For instance, fluctuation in testosterone levels when a child is in distress has been found to be indicative of fathering styles. If a father's testosterone levels decrease in response to hearing their baby cry, it is an indication of empathizing with the baby. This is associated with increased nurturing behavior and better outcomes for the infant[63].
It is essential to discuss erectile dysfunction with your doctor, so any serious underlying causes can be excluded and treatment options can be discussed. Many men are embarrassed discussing this issue with their doctor, or even their partner. Open communication with your doctor, and in your relationship, is important for effectively managing this common problem.
Cross-sectional studies conducted at the time of diagnosis of BPH have failed to show consistent differences in testosterone levels between patients and controls. A prospective study also failed to demonstrate a correlation between testosterone and the development of BPH (Gann et al 1995). Clinical trials have shown that testosterone treatment of hypogonadal men does cause growth of the prostate, but only to the size seen in normal men, and also causes a small increase in prostate specific antigen (PSA) within the normal range (Rhoden and Morgentaler 2005). Despite growth of the prostate a number of studies have failed to detect any adverse effects on symptoms of urinary obstruction or physiological measurements such as flow rates and residual volumes (Snyder et al 1999; Kenny et al 2000, 2001). Despite the lack of evidence linking symptoms of BPH to testosterone treatment, it remains important to monitor for any new or deteriorating problems when commencing patients on testosterone treatment, as the small growth of prostate tissue may adversely affect a certain subset of individuals.
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