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

Also, due to the intake of these synthetic substances, men start behaving in a very excited way, as well as demonstrate high levels of aggression and even violence. So, the men’s behavior may be antisocial. In addition, the men will experience breast enlargement and testicular shrinkage. The other adverse effects include hypertension, tumor growth, heart attacks and strokes, as well as development of liver disorders. It’s obvious that the numerous dangers of steroid use far outweigh a few benefits which they bring.
12)  Use Aswaghanda and Collagen Protein:  This adaptogenic herb has been shown to reduce stress hormone, increase DHEA and boost testosterone levels.  You can take the Cortisol Defense to help you get restorative sleep at night which will support your testosterone.  In addition, I personally enjoy using the Organic Bone Broth Collagen in addition to the Amino Strong for a post weight training shake.  This protein powder has all the benefits of collagen protein and it has 500 mg of high potency ashwagandha in each serving!
This doesn’t mean Super Test is perfect — we take a closer look at some of its ingredients below — but it beats out the competition. Every other supplement we looked at either didn’t have all four ingredients, overdosed us on vitamins or minerals (a good way to develop kidney and liver problems), contained ingredients that would harm us, or some combination thereof.
Sweet potatoes, white potatoes, russets, red potatoes, purple potatoes, etc. If it’s a potato, you should be eating it. Potatoes are excellent no-gluten source of testosterone boosting carbohydrates, and also very dense in nutrients. Stock pile your pantry full of them, and make potatoes your main carbohydrate source. Heck, if you can find potato chips that haven’t been laden with polyunsaturated fats, go for those too.
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.
The same study showed that drinking did, however, lower semen count and quality. And I want to remind you – this is an article  on improving testosterone levels, not general health as there are a lot of studies that show drinking leads to an assortment of health issues. This acute spike in Testosterone could be due to the effect alcohol has on libido, and also the energy influx in the liver?
Let’s do a quick review of what I shared in the introduction to this series. August of last year was a tough month for me, primarily because of a huge and grueling project we were in the midst of here on the site. I was stressed out and my sleeping, healthy eating habits, and workout regimen all suffered. At the end of the month I got my testosterone levels tested and found that my total T was 383 ng/dL and my free T was 7.2 pg/mL – close to the average for an 85-100-year-old man.
Overall there is evidence that testosterone treatment increases lean body mass and reduces obesity, particularly visceral obesity, in a variety of populations including aging men. With regard to muscle changes, some studies demonstrate improvements in maximal strength but the results are inconsistent and it has not been demonstrated that these changes lead to clinically important improvements in mobility, endurance or quality of life. Studies are needed to clarify this. Changes in abdominal obesity are particularly important as visceral fat is now recognised as predisposing the metabolic syndrome, diabetes and cardiovascular disease.
Disclaimer. We do not claim that we have got the approval from Food and Drug Administration when offering our products and services on this website. We do not try to position the testosterone booster supplements the information on which we give on this website as the professional treatment alternative. Also, we do not appeal to the users to practice self-treatment by using the content here. We only publish the content that the authors provide to us. Therefore, these articles may not express our opinion, only the opinion of the article writers. In addition, take into consideration that the content writers are not the healthcare practitioners. Hence, it follows that the writers’ opinions should not be perceived as medical advice. We emphasize that the diet pills intake should be a decision taken based on the recommendations of the real healthcare practitioner since only the doctor can make a diagnosis and prescribe any treatment. We cooperate with the affiliated websites which can publish their content on this website for advertising purposes. Consequently, we do not have any bearing upon trademarks, service marks, logos, and brand names that come from the affiliated websites. Moreover, the content provided by the advertising partners is subject to amendments and deletion at the content owners’ own discretion.
Everyone knows that carbohydrates are extremely important for testosterone production, but instead of reaching for grains during your next meal, stack your plate high with potatoes. Research reveals that grains have inflammatory properties, but the testosterone-friendly starches in potatoes will have the bodybuilder in your life smiling at dinnertime!
That said, a group of researchers at the National University of Malaysia did a systemic literature review of longjack, looking for clinical research that demonstrated a relationship between the shrub and testosterone levels. Of 150 articles, only 11 met their inclusion criteria — involving humans and scientifically rigorous. However, of those 11 studies, seven “revealed remarkable association” between using longjack and improving male sexual health, while the remaining four “failed to demonstrate sufficient effects.” The team concluded that longjack looks “promising” when it comes to raising low testosterone, and that there is convincing evidence that it works.

Aromatase inhibitors can boost testosterone on their own, but they can also complement other testosterone boosters. If you take a supplement that increases testosterone without inhibiting the aromatase enzyme (through hypothalamic stimulation, for instance), you may find yourself with more estradiol than you need, a situation that taking an aromatase inhibitor may remedy.
It is important not to use any DHEA product without the supervision of a professional. Find a qualified health care provider who will monitor your hormone levels and determine if you require supplementation. Rather than using an oral hormone supplementation, I recommend trans-mucosal (vagina or rectum) application. Skin application may not be wise, as it makes it difficult to measure the dosage you receive. This may cause you to end up receiving more than what your body requires.
Use natural grooming products. Most grooming products these days contain parabens, another type of xenoestrogen. And by most, I mean more than 75% of all products. To reduce my exposure as much as possible, I became a hippy during my experiment and started using all natural, paraben-free grooming products. You can find most of these items at most health food stores:
To find the best testosterone booster, we collected every supplement available on BodyBuilding.com, and cross-checked our list against the top results on best of lists like MensFitness, BroScience, and BodyNutrition. We only looked at pills since some of the ingredients in testosterone boosters have a reputation for tasting bad, and powders just prolong the experience. There are a lot — 133 of them to be precise — and they all claim to boost testosterone levels. Testosterone (for men) is “thought to regulate sex drive (libido), bone mass, fat distribution, muscle mass and strength, and the production of red blood cells and sperm.” If a supplement can increase your natural testosterone levels, the rest should follow. As we mentioned above, it’s not that simple, and at best, you’ll experience only a short-lived boost.

Once you have surpassed your early twenties, natural testosterone levels slowly begin to decline. This is a natural occurrence which occurs in all men, however can be prevented to some extent by ensuring your diet is rich in vitamins, minerals and quality fats. You can also supplement with a Natural Testosterone Booster which will work by encouraging your body to produce more Testosterone, back up to levels you could produce in your younger years.
Studies have demonstrated reduced testosterone levels in men with heart failure as well as other endocrine changes (Tappler and Katz 1979; Kontoleon et al 2003). Treatment of cardiac failure with chronic mechanical circulatory support normalizes many of these changes, including testosterone levels (Noirhomme et al 1999). More recently, two double-blind randomized controlled trials of testosterone treatment for men with low or low-normal serum testosterone levels and heart failure have shown improvements in exercise capacity and symptoms (Pugh et al 2004; Malkin et al 2006). The mechanism of these benefits is currently unclear, although a study of the acute effects of buccal testosterone given to men with chronic cardiac failure under invasive monitoring showed that testosterone increased cardiac index and reduced systemic vascular resistance (Pugh et al 2003). Testosterone may prove useful in the management of cardiac failure but further research is needed.

Most people associate testosterone with facial hair, gigantic muscles & illegal steroids.  Naturally produced testosterone plays a very important role in male/female metabolic function.  Lowered testosterone is a chronic epidemic that is threatening lives all around the world.  This article will go over 12 ways to boost testosterone levels naturally through healthy lifestyle measures.
Growth of spermatogenic tissue in testicles, male fertility, penis or clitoris enlargement, increased libido and frequency of erection or clitoral engorgement occurs. Growth of jaw, brow, chin, and nose and remodeling of facial bone contours, in conjunction with human growth hormone occurs.[21] Completion of bone maturation and termination of growth. This occurs indirectly via estradiol metabolites and hence more gradually in men than women. Increased muscle strength and mass, shoulders become broader and rib cage expands, deepening of voice, growth of the Adam's apple. Enlargement of sebaceous glands. This might cause acne, subcutaneous fat in face decreases. Pubic hair extends to thighs and up toward umbilicus, development of facial hair (sideburns, beard, moustache), loss of scalp hair (androgenetic alopecia), increase in chest hair, periareolar hair, perianal hair, leg hair, armpit hair.
Dr. Anthony's Notes: Creatine is damn effective. Period. It's research proven to benefit testosterone, energy levels, muscle preservation, and your brain function. Although creatine can be found naturally in a good high-protein diet, taking 5g daily is a great idea for most guys – especially those over 35. Remember to take your creatine AWAY from caffeine – the two substances inhibit each other's absorption. Verdict: this is one of the natural testosterone supplements that work. Best Food Sources: wild game (including venison, elk, buffalo, and bison), grass-fed beef, organic chicken, organic turkey, and wild-caught fish. How To Take Creatine Monohydrate: 5g daily away from caffeine.
That said, a group of researchers at the National University of Malaysia did a systemic literature review of longjack, looking for clinical research that demonstrated a relationship between the shrub and testosterone levels. Of 150 articles, only 11 met their inclusion criteria — involving humans and scientifically rigorous. However, of those 11 studies, seven “revealed remarkable association” between using longjack and improving male sexual health, while the remaining four “failed to demonstrate sufficient effects.” The team concluded that longjack looks “promising” when it comes to raising low testosterone, and that there is convincing evidence that it works.
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).
The University of Connecticut recently published findings stating that those who supplemented with whey protein produced less cortisol, a stress hormone, than those who did not supplement. Cortisol lowers production of sex hormones and is also responsible for belly fat formation. Ricotta is an excellent source of natural whey protein and amino acids, both of which are essential to muscle growth and avoiding the spare tire.
When we face stress, our adrenal glands secrete cortisol to prepare our bodies and minds to handle the stressful situation — the primal fight-or-flight response. In small dosages, cortisol is fine and even useful, but elevated cortisol levels for prolonged periods can do some serious damage to our bodies and minds. One area that seems to take a hit when cortisol is high is our testosterone levels. Several studies have shown a link between cortisol and testosterone. When cortisol levels are high, testosterone levels are low; and when testosterone levels are high, cortisol levels are low.

In a recent study of male workers, men with low testosterone levels had an increased chance of severe erectile dysfunction (Kratzik et al 2005), although such a link had not been found previously (Rhoden et al 2002). Certainly erectile dysfunction is considered part of the clinical syndrome of hypogonadism, and questions regarding erectile dysfunction form part of the clinical assessment of patients with hypogonadism (Morley et al 2000; Moore et al 2004).
There is a polymorphic CAG repeat sequence in the androgen receptor gene, which codes for a variable number of glutamine amino acids in the part of the receptor affecting gene transcription. A receptor with a short CAG sequence produces greater activity when androgens attach, and men with shorter CAG polymorphisms exhibit androgenic traits, such as preserved bone density (Zitzmann et al 2001) and prostate growth during testosterone treatment (Zitzmann et al 2003). Indirect evidence of the importance of androgens in the development of prostate cancer is provided by case control study findings of a shorter, more active CAG repeat sequence in the androgen receptor gene of patients with prostate cancer compared with controls (Hsing et al 2000, 2002).
“I'm having great results. Everybody is seeing a difference. People say, “You look good! Did you lose weight? What are you taking?” I'm 59, and I'm bringing my belt down a couple different notches. I couldn't break 180 lbs for nothing, no matter what I tried. Now it's 175 lbs. and she's going from there. I was just doing it for the belly -- no matter what I just couldn't get rid of the belly (until now). And I'm not as tired as I used to be.“
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.
If you still feel the need to supplement, keep in mind that supplemental magnesium is more likely than dietary magnesium to cause adverse effects, which is why the FDA fixed at 350 mg the Tolerable Upper Intake Level for magnesium supplementation in adults. Also, you may want to avoid magnesium oxide: it has poor bioavailability (rats absorbed only 15% in one study,[43] and humans only 4% in another[44]) and can cause intestinal discomfort and diarrhea.
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.

“I'm 55 years old and hitting the ball further than I've ever hit, and I'm not getting tired going 18 holes! And when I play softball I'm hitting the ball further. I work for the DWP in LA and it's a very physically demanding job. Andro400 really helps because we work 16 hour days a lot. I was turning down a lot of overtime, but when I started taking Andro400, it got me through the day. I really notice a difference – even my wife did. It really works!” 

Recently, a panel with cooperation from international andrology and urology societies, published specific recommendations with regard to the diagnosis of Late-onset Hypogonadism (Nieschlag et al 2005). These are summarized in the following text. It is advised that at least two serum testosterone measurements, taken before 11 am on different mornings, are necessary to confirm the diagnosis. The second sample should also include measurement of gonadotrophin and prolactin levels, which may indicate the need for further investigations for pituitary disease. Patients with serum total testosterone consistently below 8 nmol/l invariably demonstrate the clinical syndrome of hypogonadism and are likely to benefit from treatment. Patients with serum total testosterone in the range 8–12 nmol/l often have symptoms attributable to hypogonadism and it may be decided to offer either a clinical trial of testosterone treatment or to make further efforts to define serum bioavailable or free testosterone and then reconsider treatment. Patients with serum total testosterone persistently above 12 nmol/l do not have hypogonadism and symptoms are likely to be due to other disease states or ageing per se so testosterone treatment is not indicated.

At the present time, it is suggested that androgen replacement should take the form of natural testosterone. Some of the effects of testosterone are mediated after conversion to estrogen or dihydrotestosterone by the enzymes aromatase and 5a-reductase enzymes respectively. Other effects occur independently of the traditional action of testosterone via the classical androgen receptor- for example, its action as a vasodilator via a cell membrane action as described previously. It is therefore important that the androgen used to treat hypogonadism is amenable to the action of these metabolizing enzymes and can also mediate the non-androgen receptor actions of testosterone. Use of natural testosterone ensures this and reduces the chance of non-testosterone mediated adverse effects. There are now a number of testosterone preparations which can meet these recommendations and the main factor in deciding between them is patient choice.

"I am so thankful to your company. I have lost 50 lbs. and went from a size 38 waist to an unbelievable 30! I am 56 years old, and now with Andro 400, I feel like I am 25 again. I was taking ramipril for high blood pressure and celebrex for my arthritis. Gone!!! My doctor has not seen a transformation like mine ever! Exercise used to be a chore -- now I have the energy to jog, exercise and be intimate with my partner when we share our love for each other. My mood has changed. I don't get stressed out anymore. I'm so happy now. I'm just a completely different man! Thank you, thank you, thank you!"
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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.
In order to discuss the biochemical diagnosis of hypogonadism it is necessary to outline the usual carriage of testosterone in the blood. Total serum testosterone consists of free testosterone (2%–3%), testosterone bound to sex hormone binding globulin (SHBG) (45%) and testosterone bound to other proteins (mainly albumin −50%) (Dunn et al 1981). Testosterone binds only loosely to albumin and so this testosterone as well as free testosterone is available to tissues and is termed bioavailable testosterone. Testosterone bound to SHBG is tightly bound and is biologically inactive. Bioavailable and free testosterone are known to correlate better than total testosterone with clinical sequelae of androgenization such as bone mineral density and muscle strength (Khosla et al 1998; Roy et al 2002). There is diurnal variation in serum testosterone levels with peak levels seen in the morning following sleep, which can be maintained into the seventh decade (Diver et al 2003). Samples should always be taken in the morning before 11 am to allow for standardization.

KOR Natural’s Test Booster packs a powerful, multi-dimensional punch for testosterone boosting, estrogen blocking, immune system support. It also contains ingredients proven to increase lean muscle mass, enhance your performance and energy levels, and even improve your mood. Low testosterone can make you feel sick and tired all the time, which obviously affects your athletic abilities. If you are looking for more definition, less fat, and a ripped physique, this is the supplement for you.


The same study showed that drinking did, however, lower semen count and quality. And I want to remind you – this is an article  on improving testosterone levels, not general health as there are a lot of studies that show drinking leads to an assortment of health issues. This acute spike in Testosterone could be due to the effect alcohol has on libido, and also the energy influx in the liver?

This is because your body is really good at self-regulating your hormone levels. So if you have normal testosterone levels, boosting above your natural base level may at best give you a few hours while your body makes, and then immediately processes out, the excess testosterone. This means you might experience higher than your average testosterone levels, but not by much, and only for a little while.
Trials of testosterone treatment in men with type 2 diabetes have also taken place. A recent randomized controlled crossover trial assessed the effects of intramuscular testosterone replacement to achieve levels within the physiological range, compared with placebo injections in 24 men with diabetes, hypogonadism and a mean age of 64 years (Kapoor et al 2006). Ten of these men were insulin treated. Testosterone treatment led to a significant reduction in glycated hemoglobin (HbA1C) and fasting glucose compared to placebo. Testosterone also produced a significant reduction in insulin resistance, measured by the homeostatic model assessment (HOMA), in the fourteen non-insulin treated patients. It is not possible to measure insulin resistance in patients treated with insulin but five out of ten of these patients had a reduction of insulin dose during the study. Other significant changes during testosterone treatment in this trial were reduced total cholesterol, waist circumference and waist-hip ratio. Similarly, a placebo-controlled but non-blinded trial in 24 men with visceral obesity, diabetes, hypogonadism and mean age 57 years found that three months of oral testosterone treatment led to significant reductions in HbA1C, fasting glucose, post-prandial glucose, weight, fat mass and waist-hip ratio (Boyanov et al 2003). In contrast, an uncontrolled study of 150 mg intramuscular testosterone given to 10 patients, average age 64 years, with diabetes and hypogonadism found no significant change in diabetes control, fasting glucose or insulin levels (Corrales et al 2004). Another uncontrolled study showed no beneficial effect of testosterone treatment on insulin resistance, measured by HOMA and ‘minimal model’ of area under acute insulin response curves, in 11 patients with type 2 diabetes aged between 33 and 73 years (Lee et al 2005). Body mass index was within the normal range in this population and there was no change in waist-hip ratio or weight during testosterone treatment. Baseline testosterone levels were in the low-normal range and patients received a relatively small dose of 100 mg intramuscular testosterone every three weeks. A good increase in testosterone levels during the trial is described but it is not stated at which time during the three week cycle the testosterone levels were tested, so the lack of response could reflect an insufficient overall testosterone dose in the trial period.
The reason I started the experiment at that point is because I know a lot of guys who live my last-August lifestyle all the time, and I wanted to see what would happen to an “average” guy who turned things around. At the same time, there was no “normal” time in my life which would have been better for me to start the experiment. My stress level and diet fluctuates throughout the year anyway, so at any point, factors in my current lifestyle would have influenced the results. I wanted to begin at “ground zero.”
If you still feel the need to supplement, keep in mind that supplemental magnesium is more likely than dietary magnesium to cause adverse effects, which is why the FDA fixed at 350 mg the Tolerable Upper Intake Level for magnesium supplementation in adults. Also, you may want to avoid magnesium oxide: it has poor bioavailability (rats absorbed only 15% in one study,[43] and humans only 4% in another[44]) and can cause intestinal discomfort and diarrhea.
Testosterone is used as a medication for the treatment of males with too little or no natural testosterone production, certain forms of breast cancer,[10] and gender dysphoria in transgender men. This is known as hormone replacement therapy (HRT) or testosterone replacement therapy (TRT), which maintains serum testosterone levels in the normal range. Decline of testosterone production with age has led to interest in androgen replacement therapy.[105] It is unclear if the use of testosterone for low levels due to aging is beneficial or harmful.[106]
Ashwagandha is shown to be effective at reducing cortisol which in turn helps with testosterone production. There are also numerous studies showing the effects on improving testosterone in infertile men (ref 80).  If you are using the Aggressive Strength product you don't need to supplement with ashwagandha as it's included in the test booster formula. Likewise if you're using Tian Chi (my daily herb drink).
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.
Present in much greater levels in men than women, testosterone initiates the development of the male internal and external reproductive organs during foetal development and is essential for the production of sperm in adult life. This hormone also signals the body to make new blood cells, ensures that muscles and bones stay strong during and after puberty and enhances libido both in men and women. Testosterone is linked to many of the changes seen in boys during puberty (including an increase in height, body and pubic hair growth, enlargement of the penis, testes and prostate gland, and changes in sexual and aggressive behaviour). It also regulates the secretion of luteinising hormone and follicle stimulating hormone. To effect these changes, testosterone is often converted into another androgen called dihydrotestosterone. 
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