There are two keys to incorporating fat in your diet: getting enough fat, and getting the right kinds of it. A study from 1984 (done, no doubt, with Big Brother watching) looked at 30 healthy men who switched from eating 40% fat (much of it saturated) to 25% fat (much of it unsaturated), with more protein and carbs to make up the difference in calories. After 6 weeks, their average serum testosterone, free testosterone, and 4-androstenedione (an important hormone for testosterone synthesis) all dropped significantly [6]. I think getting 40% of your calories from fat is too little – I recommend 50-70% of calories from fat, or even more in some cases.
Sexual arousal - boosting testosterone can improve sexual arousal, even if you have normal testosterone levels. Higher levels of testosterone can make it easier for you to get aroused and can boost your sex drive generally. While this doesn’t affect the physical action of your erections, if you are not getting hard because you’re not aroused then boosting testosterone could help.
Over time, the testicular “machinery” that makes testosterone gradually becomes less effective, and testosterone levels start to fall, by about 1% a year, beginning in the 40s. As men get into their 50s, 60s, and beyond, they may start to have signs and symptoms of low testosterone such as lower sex drive and sense of vitality, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often called hypogonadism (“hypo” meaning low functioning and “gonadism” referring to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the United States. Yet it is an underdiagnosed problem, with only about 5% of those affected receiving treatment.
I started with the shots. Wowee! the effect was like night and day. For two years I was like a teenager. But then I noticed some REALLY risky (Health) behavior ( and memory gaps) and bad decisions with long-term implications(i.e judgement). So I tried stopping TRT (four years on the pumps),within four months, mood swings like menopause: snarly with co workers (not good in nursing), grumpy with everyone, switch from jovial to downcast in an instant (I’m male). Had to go back on and do an 18 mth taper, coupled with exercise. No TRT, makes exercise SO hard to do. Muscles seem so much more aware of stiffness.
Tongkat ali (a.k.a. Longjack, a.k.a. Eurycoma Longifolia) is a foundational compound of Ayurveda, commonly used as an aphrodisiac. Similar to DHEA, longjack has been found to be effective in both men and women for improving libido, total and free testosterone concentrations as well as muscle mass and strength in men and women! And, unlike many of the other old world herbs commonly touted as natural testosterone boosters, longjack actually has a fair amount of human research denoting its benefits.

The problem with testosterone therapy is several reasons you may have to stop taking it.Despite what you hear the chance of enlarged prostate is very real.It happened to me.Also blood too thick only cure by phlebotomy(having blood drawn more often than you will probably want to be harpooned to thin blood.) I didn’t sleep well either(especially as trips to bathroom got more frequent from BPH)then you really need several labs getting estradiol and testosterone levels correct and hcg and arimidex in the mix also (or Clomid) but dht issues are very real and not addressed in most try protocol.finisteride has many bad side effects as does avodart. Testosterone therapy is great for some people but if you’re low normal like I was I wish I would have left well enough alone. Our bodies have a lot more hormones to balance than just testosterone and estradiol and the crash can be a little rough if you have to stop. Be smart and have Clomid,Adex,and hcg on hand just in case.Good luck to all on trt(and those stopping it)
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Testosterone begins with cholesterol. In fact, every single sex hormone you make you synthesize from cholesterol – that’s one reason a “heart healthy” low-fat, low-cholesterol diet limits your performance. Fat and cholesterol don’t make you fat. They give your body the building blocks to create abundant testosterone and other sex hormones, which actually makes you lose weight and build muscle, especially if your current testosterone levels are low [1].
Bisphenol-A also known under the name of BPA is a chemical compound which is very widespread for manufacturing a wide spectrum of plastic items and aluminum cans. Many studies have already proven the fact that even the smallest amount of BPA is very harmful to the human health. This compound causes hormonal imbalance and even may lead to prostate cancer.
I am now 65 & have had Low-T problems since I was about 60. I took topical Testosterone for a few years until insurance stopped covering it. Then I took injections at a Men's Health-Low-T Clinic. Then I was diagnosed with Prostate Cancer & was told to stop taking Testosterone. I underwent radiation treatment to cure the Prostate cancer, but since there is a theory that taking Testosterone can lead to Prostate cancer, I have chosen not to resume taking it. While I am glad to be free of the cancer, I have been feeling extremely fatigued & tired all the time to the point that doing much of anything like a little yard work would leave me exhausted for days.
Testosterone. During adolescence and early adulthood, testosterone levels in men are naturally high resulting in a feeling of strength, sexual charge and vitality. But as men get older, the aging process causes testosterone levels to decline, often resulting in a decrease in sexual desire, decrease in muscle mass, excessive weight gain, feeling tired all day, extreme mood swings, insomnia, depression and hair loss.
The IOM report estimated that a study of whether there is an increased risk of prostate cancer in men on testosterone therapy might require following 5,000 men for three to five years. Before launching such an endeavor, the report recommended more firmly establishing the effectiveness of testosterone-replacement therapy, saying that studies of long-term risks and benefits should be conducted only after short-term efficacy has been proven. That means the male equivalent of the WHI remains far off.
Testosterone causes prostate cancer. Since the 1940s, it was commonly believed in the medical field that high testosterone levels were the cause of prostate cancer in men. Doctors reached this conclusion because two scientists in 1941 noticed that prostate cancer regressed in a patient after they castrated him and his T levels subsequently declined. This conclusion was based on the results from a single patient!
Testosterone levels naturally rise in response to sexual arousal and activity. Men with higher levels of testosterone usually have greater sexual activity. Older men need more testosterone for libido and erectile function. But it’s important to note that erectile dysfunction is often due to other conditions or medications rather than low testosterone levels.
Then in 2017, Melville carried out another study on DAA.[4] This time he recruited 22 men in a randomized, double-blind fashion and had them consume either a placebo or 6g of DAA. After 12 weeks of supplementation, researchers observed that DAA had no significant impact on resting levels of either free or total testosterone. Any improvements in strength or hypertrophy were similar to those in the placebo group.
Ashwagandha: One of the hottest herbs out there right now, this adaptogen packs a one-two punch. First, it helps the body fight off stress: According to one Indian Journal of Psychological Medicine study, ashwagandha has a cortisol-lowering effect—a major benefit to anyone who wants their body to be more T-friendly. And, second, it can also support your T-boosting training efforts. One Journal of the International Society of Sports Nutrition study, for example, found that men who supplemented with ashwagandha saw significantly greater strength and T gains after eight weeks of resistance training than those who took a placebo.
Short bursts of timed intense activity — known as high-intensity interval training or HIIT — trigger the body to make more testosterone than less-than-intense aerobic or endurance exercise, says La Puma. Spurts of activity stimulate androgen-sensitive tissue, he explains, which tells the body to make more testosterone. Strength training has also been shown to increase testosterone.
Testosterone may prove to be an effective treatment in female sexual arousal disorders,[52] and is available as a dermal patch. There is no FDA approved androgen preparation for the treatment of androgen insufficiency; however, it has been used off-label to treat low libido and sexual dysfunction in older women. Testosterone may be a treatment for postmenopausal women as long as they are effectively estrogenized.[52]

A recent study conducted on trained subjects showed that squats stimulated a greater testosterone response than leg presses.10 Stick with multijoint exercises like squats, bench presses, and deadlifts—the kinds of compound lifts that'll help jack up your testosterone levels. Since machines isolate a muscle you're working (less stabilizer activity), they're not as good a choice compared to free weights.

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.
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).
^ Jump up to: a b Sapienza P, Zingales L, Maestripieri D (September 2009). "Gender differences in financial risk aversion and career choices are affected by testosterone". Proceedings of the National Academy of Sciences of the United States of America. 106 (36): 15268–73. Bibcode:2009PNAS..10615268S. doi:10.1073/pnas.0907352106. PMC 2741240. PMID 19706398.

Other stereotypical "macho" behaviors can affect testosterone in women, according to a 2015 report in the Proceedings of the National Academy of Sciences. For example, posing in a powerful way increases testosterone in both women and men. The 2015 report showed that having women role-play a position of power — acting like a boss — had the same effect.

Testosterone boosters are formulated for men in most cases, though there are a few brands that are appropriate for women. These are generally for men who want to improve their lean muscle mass, stamina, and energy levels. If you have low testosterone levels, these are great to ward off symptoms like low energy, excessive body fat, and a low sex drive. Some athletes might benefit from these boosters. You should always check with your doctor before adding these supplements or any other supplements to your regimen, particularly if you have chronic health conditions or if you are already taking medications or supplements.


Hi my names Graham. I’ve suffered with Gyno for most of my adult life. Even when I’ve lost a ton of weight , those two unhelpful bags of fat are still there. To save me 4 to 6 grand on liposuction or surgery, will an estrogen blocker and testosterone booster help. I’ve also heard of a cream called andractim that can help , but they are expensive. Any advice would be great . Thanks.
Testosterone decreases body fat. Testosterone plays an important role in regulating insulin, glucose, and fat metabolism. As our T levels decrease, our body’s ability to regulate insulin, glucose, and fat metabolism decreases, which in turn causes adipose tissue (i.e. fat) to begin accumulating. To add insult to injury, that increased adipose tissue may also contribute to further decreasing testosterone levels because it converts testosterone into estrogen.
In addition to weightlifting, studies have shown that HIIT workouts can also help boost testosterone levels. For those of you who don’t know, HIIT stands for high-intensity interval training. It calls for short, intense bursts of exercise, followed by a less-intense recovery period. You repeat with the intense/less-intense cycle several times throughout the workout. In addition to increasing T, HIIT has been shown to improve athletic conditioning and fat metabolism, as well as increase muscle strength.
For example, testosterone can increase the hematocrit, the percentage of red blood cells in the bloodstream. If the hematocrit goes up too high, we worry about the blood becoming too viscous or thick, possibly predisposing someone to stroke or clotting events. Although, frankly, in a review that I wrote in the New England Journal of Medicine* where we reviewed as much of this as we could, we found no cases of stroke or severe clotting related to testosterone therapy. Nevertheless, the risk exists, so we want to be careful about giving testosterone to men who already have a high hematocrit, such as those with chronic obstructive pulmonary disease, or those who have a red-blood-cell disorder.
As you cut these dietary troublemakers from your meals, you need to replace them with healthy substitutes like vegetables and healthy fats (including natural saturated fats!). Your body prefers the carbohydrates in micronutrient-dense vegetables rather than grains and sugars because it slows the conversion to simple sugars like glucose, and decreases your insulin level. When you cut grains and sugar from your meals, you typically will need to radically increase the amount of vegetables you eat, as well as make sure you are also consuming protein and healthy fats regularly.
The basis for my thinking that T levels could be boosted by cold baths came from a post I wrote a few years ago on the benefits of cold showers. One benefit I found in my research was that they could increase testosterone levels. I mentioned a 1993 study done by the Thrombosis Research Institute in England that found increased T levels after taking a cold shower. Here’s the thing. I can’t find a link to the original source and I can’t find any other studies that support this claim! So without supporting research, I’m unsure of the effects of cold showers on testosterone.

Alcohol has constantly been shown to lower testosterone levels. It’s even worse if you’re a heavy beer drinker. Wanna know why? Because beer raises your estrogen levels due to the phytoestrogens that are produced from the hops used to make beer. If that’s not enough, studies have shown that alcoholics have lower levels of testosterone than non-alcoholics.
Testosterone is an anabolic steroid hormone that plays a critical role in metabolism, sex drive, muscle building, mood regulation, memory & cognitive function.  Normal testosterone levels play a huge role in maintaining optimal weight as well as reducing risk of degenerative diseases such as osteoporosis, heart disease, diabetes, & certain cancers (1, 2, 3).
Unfortunately, in the modern world, stresses and emotional exhaustion lie in wait for men at every step. Nowadays, burnout is a constant state for many men. Of course, this causes great harm to the men’s health. Stresses drain of vitality and affect emotional state. Besides, they are also very dangerous for the nervous system. The nature is wise. And the body of a man who is not subject to stress can produce more testosterone.
Cross-sectional studies have not shown raised testosterone levels at the time of diagnosis of prostate cancer, and in fact, low testosterone at the time of diagnosis has been linked with more locally aggressive and malignant tumors (Massengill et al 2003; Imamoto et al 2005; Isom-Batz et al 2005). This may reflect loss of hormone related control of the tumor or the effect of a more aggressive tumor in decreasing testosterone levels. One study found that 14% of hypogonadal men, with normal digital rectal examination and PSA levels, had histological prostate cancer on biopsy. It is possible that low androgen levels masked the usual evidence of prostate cancer in this population (Morgentaler et al 1996). Most longitudinal studies have not shown a correlation between testosterone levels and the future development of prostate cancer (Carter et al 1995; Heikkila et al 1999; Stattin et al 2004) but a recent study did find a positive association (Parsons et al 2005). Interpretation of such data requires care, as the presentation of prostate cancer could be altered or delayed in patients with lower testosterone levels.
Every vitamin, mineral, and ingredient that affects the human body can be taken in enough quantities that they are harmful, or toxic, even the ones that — at lower levels — are beneficial or necessary. Unfortunately, testosterone boosters contain a lot of ingredients that are not well understood. This means in addition to not being able to confirm whether certain ingredients increase testosterone, the scientific and medical communities also don’t know at what levels many ingredients become toxic. On the up side, you might need to eat several pounds of a particular leafy plant before it becomes harmful. On the down side, it could be significantly less that pushes you over your body’s limit. We simply don’t know how little or how much the human body can tolerate. We recommend keeping your doctor in the loop when you add any supplement with unproven ingredients into your diet — they’ll be able to help you find and track any undesired side-effects that these ingredients might cause.
Before assessing the evidence of testosterone’s action in the aging male it is important to note certain methodological considerations which are common to the interpretation of any clinical trial of testosterone replacement. Many interventional trials of the effects of testosterone on human health and disease have been conducted. There is considerable heterogenicity in terms of study design and these differences have a potential to significantly affect the results seen in various studies. Gonadal status at baseline and the testosterone level produced by testosterone treatment in the study are of particular importance because the effects of altering testosterone from subphysiological to physiological levels may be different from those of altering physiological levels to supraphysiological. Another important factor is the length of treatment. Randomised controlled trials of testosterone have ranged from one to thirty-six months in duration (Isidori et al 2005) although some uncontrolled studies have lasted up to 42 months. Many effects of testosterone are thought to fully develop in the first few months of treatment but effects on bone, for example, have been shown to continue over two years or more (Snyder et al 2000; Wang, Cunningham et al 2004).
The normal development of the prostate gland is dependent on the action of testosterone via the androgen receptor, and abnormal biosynthesis of the hormone or inactivating mutations of the androgen receptor are associated with a rudimentary prostate gland. Testosterone also requires conversion to dihydrotestosterone in the prostate gland for full activity. In view of this link between testosterone and prostate development, it is important to consider the impact that testosterone replacement may have on the prevalence and morbidity associated with benign prostatic hypertrophy (BPH) and prostate cancer, which are the common conditions related to pathological growth of the prostate gland.
If you think you may have a medical emergency, call your healthcare provider or 911 immediately. Any mention of products or services is not meant as a guarantee, endorsement, or recommendation of the products, services, or companies. Reliance on any information provided is solely at your own risk. Please discuss any options with your healthcare provider.
Nutritional developers formulated Nugenix® with Testofen®, a key natural ingredient to help boost “free” testosterone along with resistance training. This key ingredient is carefully extracted from the fenugreek plant. A Testofen® study in Irvine, California indicated positive free testosterone-related results. Nugenix also includes L-Citrulline Malate, Tribulus, Zinc, plus Vitamins B6 and B12 to help promote overall health and performance.*
The all-new True Grit Test Booster is scientifically engineered to deliver the most powerful testosterone-boosting ingredients on the market today. This powerful 3-in-1 formula offers the benefits of both free and total testosterone boost as well as cortisol balance. Using powerful clinically studied key ingredients, True Grit Test Booster works with the body to naturally increase testosterone levels while staying within the normal healthy range
Dr. Resnick and colleagues assessed 788 participants in the cognitive function arm of the TTrials but focused on the 493 participants who were classified as having age-associated memory impairment with a confirmation of both subjective and objective indicators of cognitive decline. The authors detected no significant effect after 1 year of testosterone treatment on either the primary outcome of verbal memory, as measured by delayed paragraph recall or on any of the secondary outcomes of visual memory, executive function, and spatial ability.1
Testosterone is the primary male sex hormone and an anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.[2] In addition, testosterone is involved in health and well-being,[3] and the prevention of osteoporosis.[4] Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss.
Preliminary research has shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can foster the production of natural testosterone, termed endogenous testosterone, in men. In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six weeks, all of the men had heightened levels of testosterone; none reported any side effects during the year they were followed.

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.[183] 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.
Like most supplements, Beast Sports contains several ingredients with little research about their long-term effects. WebMD describes Suma powder, Rhodiola Rosea, Cissus quadrangularis, Tribulus extract, and ashwagandha extract as possibly safe when taken for a short period of time (usually around 6-10 weeks). However, their long-term safety remains unknown. It also has a few ingredients, like cyanotis vaga root, safed musli, and polygonum cispidatum root extract for which there is a lack of data on even short term safety.

Testosterone begins with cholesterol. In fact, every single sex hormone you make you synthesize from cholesterol – that’s one reason a “heart healthy” low-fat, low-cholesterol diet limits your performance. Fat and cholesterol don’t make you fat. They give your body the building blocks to create abundant testosterone and other sex hormones, which actually makes you lose weight and build muscle, especially if your current testosterone levels are low [1].


^ 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.
I’ve been on testosterone replacement for over 3 years and at first I did the shots and my mood swings were ridiculous, my skin broke out on my chest and shoulders, and my henatocrit went to 55%. I finally got fed up with doing shots every two weeks and switched to Gel and it’s been so much better. It actually increases my levels which is rare for most men. I do 12.5 mg, three pumps a day, and this keeps My level between 500 and 600. My hematocrit is 48.5 and no mood swings.

Statins are some of the most prescribed drugs in the world for reducing cholesterol levels and preventing heart disease. Various studies in the 1990s, including a study published in the ‘European Journal of Clinical Nutrition,’ supported the claim that Fenugreek could help reduce cholesterol levels[2]. One possible explanation is the high fiber content in fenugreek.  A fiber-rich diet has been shown to help reduce the levels of LDL (‘bad’ cholesterol) in your blood. (Note: The validity of the various studies from the 1990s have been questioned though because of small sample sizes[3])


Testosterone levels naturally rise in response to sexual arousal and activity. Men with higher levels of testosterone usually have greater sexual activity. Older men need more testosterone for libido and erectile function. But it’s important to note that erectile dysfunction is often due to other conditions or medications rather than low testosterone 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. In the bones, estradiol accelerates ossification of cartilage into bone, leading to closure of the epiphyses and conclusion of growth. In the central nervous system, testosterone is aromatized to estradiol. Estradiol rather than testosterone serves as the most important feedback signal to the hypothalamus (especially affecting LH secretion).[119] In many mammals, prenatal or perinatal "masculinization" of the sexually dimorphic areas of the brain by estradiol derived from testosterone programs later male sexual behavior.[120]

There have been case reports of development of prostate cancer in patients during treatment with testosterone, including one case series of twenty patients (Gaylis et al 2005). It is not known whether this reflects an increase in incidence, as prostate cancer is very common and because the monitoring for cancer in patients treated with testosterone is greater. Randomized controlled trials of testosterone treatment have found a low incidence of prostate cancer and they do not provide evidence of a link between testosterone treatment and the development of prostate cancer (Rhoden and Morgentaler 2004). More large scale clinical trials of longer durations of testosterone replacement are required to confirm that testosterone treatment does not cause prostate cancer. Overall, it is not known whether testosterone treatment of aging males with hypogonadism increases the risk of prostate cancer, but monitoring for the condition is clearly vital. This should take the form of PSA blood test and rectal examination every three months for the first year of treatment and yearly thereafter (Nieschlag et al 2005). Age adjusted PSA reference ranges should be used to identify men who require further assessment. The concept of PSA velocity is also important and refers to the rate of increase in PSA per year. Patients with abnormal rectal examination suggestive of prostate cancer, PSA above the age specific reference range or a PSA velocity greater than 0.75 ng/ml/yr should be referred to a urologist for consideration of prostate biopsy.

The mechanism of age related decreases in serum testosterone levels has also been the subject of investigation. Metabolic clearance declines with age but this effect is less pronounced than a reduction in testosterone production, so the overall effect is to reduce serum testosterone levels. Gonadotrophin levels rise during aging (Feldman et al 2002) and testicular secretory responses to recombinant human chorionic gonadotrophin (hCG) are reduced (Mulligan et al 1999, 2001). This implies that the reduced production may be caused by primary testicular failure but in fact these changes are not adequate to fully explain the fall in testosterone levels. There are changes in the lutenising hormone (LH) production which consist of decreased LH pulse frequency and amplitude, (Veldhuis et al 1992; Pincus et al 1997) although pituitary production of LH in response to pharmacological stimulation with exogenous GnRH analogues is preserved (Mulligan et al 1999). It therefore seems likely that there are changes in endogenous production of GnRH which underlie the changes in LH secretion and have a role in the age related decline in testosterone. Thus the decreases in testosterone levels with aging seem to reflect changes at all levels of the hypothalamic-pituitary-testicular axis. With advancing age there is also a reduction in androgen receptor concentration in some target tissues and this may contribute to the clinical syndrome of LOH (Ono et al 1988; Gallon et al 1989).

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