The male sex hormoneTestosterone is the most important male sex hormone which ‘makes a man a man’. However, women also have testosterone in their bodies. Thus, women are a bit ‘male’ - the same applies vice versa for female sex hormones in men. With increasing age, the body’s production of testosterone decreases more and more. According to a study, 20 - 40 % of men suffer from testosterone deficiency as of the age of 40 to 50. Apart from decreasing muscle power, hair loss and changes in libido, testosterone can have considerable impact on health. Testosterone also plays an important role in physiological processes: Various metabolic processes like e.g. development of the body and even blood formation depend on testosterone. Apart from the gender-specific resp. physiological functions, the building up effects of testosterone are of particular interest to athletes. In this article you can find more information on how to stabilize your testosterone values.
This article guides you through the complex world of testosterone. We provide a detailed definition of testosterone and explain the importance of balanced testosterone levels, especially for the male body. We explain the negative impact of a deficiency on your body, on your performance and on your libido. However, excess testosterone also unbalances the body and has negative effects. Therefore, we have also included this topic. We give you tips on how to increase testosterone values naturally. On the basis of recent studies, we describe the topics sports, cardiovascular diseases, hair loss and prostate cancer in a comprehensible manner.
Very important: This article is not only addressed to the male reader. Testosterone is also vital for female health!
What is testosterone?
Testosterone is the most important male sex hormone (androgen). It belongs to the so-called steroid hormones and has building up (anabolic) effects in the body. It is, for example, responsible for sexual desire (libido), sperm production and the growth of the external sex organs. Women also produce testosterone in small quantities. 
In men, 90 % of testosterone is produced in the testicles and in women in the ovaries. In addition, low production takes place in the adrenal cortex. 
What your body needs testosterone for
Even though it is referred to as a male sex hormone, small quantities are also present in the female body. The building up (anabolic) steroid hormone influences various functions in both sexes: 
- physical build and body development
- building of muscle mass
- increases the fat-free muscle mass in the body
- development of secondary sex characteristics (in the womb)
- sperm production in men
- libido enhancer
- bone stability and bone growth
- body hair
- blood formation
- lowers the lipid content
Good to know: The hormone values in men can be ten times higher than in women. Therefore, the much higher concentration of this hormone in men is one of the reasons why men have a higher muscle percentage than women. In contrast, the female sex hormone estrogen increases the fat percentage in the body. 
During puberty, testosterone is produced in considerable quantities. It is responsible for the growth of pubic and body hair (beard and chest hair). Testosterone production in men declines with age due to physiological causes. In women, the level is less depending on age, however it also decreases over time. 
Studies have shown that 20 - 40 % of men as of the age of 40 to 50 suffer from testosterone deficiency.
Many of the affected men only notice it when symptoms/ complications of testosterone deficiency occur. Timely measuring of testosterone in the body can assist in remedying the problem. Then, appropriate measures can be taken. 
Testosterone deficiency - Symptoms
Symptoms of testosterone deficiency range from decreasing muscle power, reduced physical performance, osteoporosis, depressive mood, increased production of abdominal fat tissue, hair loss, anaemia, high blood sugar values to diabetes and increased libido (erectile dysfunction) as well as reduced sperm quantity in men. 
Testosterone deficiency - Causes
What causes testosterone deficiency?
Reasons for low testosterone levels in men and women can be:
- severe malnutrition
- severe chronic diseases
- chronic stress
- major / serious operations
- alcohol or drug abuse
- Addison’s disease with too low cortisol levels
- liver cirrhosis
- long-term use of cortisone and hormone preparations 
Testosterone deficiency = menopause?
Due to the prevalence of testosterone deficiency in men, the existence of male menopause, the so-called andropause, is being discussed. However, unlike in women, only one in ten men is affected. 
Especially in women, menopause and hormonal contraceptives can lead to low testosterone levels. Ovarian subfunction (ovarian insufficiency) and therapy with drugs, the so-called antiandrogens, can also induce testosterone deficiency.
In men, hypofunction of the gonads (e.g. Klinefelter’s-syndrome) or misuse of anabolic steroids can lead to low testosterone values. 
Good to know: Antiandrogens
Antiandrogens are drugs used to reduce the production of male sex hormones. They are used for treatment of prostate cancer, skin diseases and increased body hair in women. Moreover, they are contained in birth control pills. 
Testosterone deficiency in young men
Low testosterone levels are seldom in men under 30 years of age. If, however, a testosterone test determines too low blood levels, these can be caused by: 
- high cholesterol levels
- high blood pressure
- alcohol and drug abuse
- anabolic steroids
- various diseases like e.g. Addison’s disease
Young people also are not necessarily spared from testosterone deficiency. However, there is no need to worry. Low testosterone levels at very young age can occur if puberty and hormonal change starts late. The beginning of puberty varies from person to person. 
Use of anabolic steroids and its side effects
Anabolic steroids are substances which influence the body’s protein synthesis whereby growth processes in the body are accelerated. This can lead to increases muscle growth. However, the use of anabolic steroids is afflicted with harmful side effects: 
In men: Abuse of anabolic steroids decreases natural production of testosterone in testicles and adrenal cortex. After ending of the use of anabolic steroids, production of hormones not continues immediately. This leads to reduced sperm count, growth of the breast and testicular shrinkage.
In women: The use of anabolic steroids leads to so-called “masculinization” with male hair growth, disorders of the menstrual cycle and deep voice.
Further side effects: Due to the muscle building properties, all muscles of the body are growing which leads to the life-threatening enlargement of the heart. The influence of excess testosterone is also apparent in lipid metabolism. The lipids shift from the so-called “good” HDL cholesterol towards the “bad” LDL cholesterol. This can lead to arteriosclerotic deposits and its consequences (thrombosis, heart attacks, strokes and liver damages). Psychic changes and mental dependence are also possible results of anabolic steroid abuse. 
Good to know:
Due to enormous side effects of anabolic steroids, the Olympic Committee prohibited testosterone already in 1976. 
Anabolic steroids have a negative impact on hormone production which can lead to testosterone deficiency in men. Women, however, suffer from stronger body hair and complications in hormonal balance. The risk of cardiovascular heart diseases and mental illnesses in both genders increases as well. 
Testosterone deficiency – Therapy
Drug therapy of low testosterone levels which are caused by a primary disease must, of course, be done under doctor supervision. Continue reading to learn how you can raise your testosterone levels naturally.
10 Natural treatments for low testosterone levels
Testosterone levels cannot be raised by prescribed drugs alone. There are various other factors that can boost testosterone production:
1. Sports: Weight training stimulates testosterone production. Short interval training has a positive effect on testosterone production. Extremely long endurance sessions, however, lead to a decrease of testosterone levels. 
2. Sufficient sleep: During sleep, testosterone is produced and enough sleep reduces stress (cortisol). 
3. Reduce cortisol: The more stress hormones are present in the body, the less testosterone is available. Cortisol is the antagonist of testosterone. R
4. Reduce excessive weight: Overweight men often have low testosterone levels. Studies indicate the following: The thicker the stomach, the lower your testosterone level. Fatty tissue is active and produces hormones - however, the wrong ones!
5. Vitamin D: Studies show a correlation between vitamin D and testosterone production. After the intake of vitamin D, increased testosterone values were measured. 
6. Zinc: Various studies proved the increase of testosterone levels after improvement of zinc levels. Zinc lowers oestrogen levels which instead increases testosterone levels. Moreover, it reduces cortisol levels which also leads to more testosterone. 
7. Magnesium: According to several studies, the intake of magnesium also leads to increased testosterone levels. When you do sports on top, this further increases testosterone levels. 
8. Selenium: Optimize your selenium levels! Also here, studies show that the intake of selenium (in case of a deficiency) increases testosterone levels. 
What all three minerals and vitamin D have in common: Test first, then supplement!!
9. Avoid alcohol and nicotine: Alcohol increases cortisol levels. Smoking lowers testosterone levels. 
10. High-fiber diet: Too high insulin levels lead to reduced testosterone levels. Therefore, foods that cause the blood glucose levels to rise sharply should be eaten less. These include: white sugar, white bread, fruit juices and highly processed foods. Whereas complex carbohydrates are beneficial for a lower increase of blood sugar levels. These can among others be found in whole-grain products, legumes, high-fibre fruit and sweet potatoes. 
Increase testosterone levels by fasting – Intermittent fasting
Recent studies proved that intermittent fasting can increase the body’s testosterone production by 200 percent. Intermittent fasting is an umbrella term used for various diets that cycle between a period of fasting and non-fasting. The most popular method is the 16:8 method. This means you are fasting for 16 hours each day and only eat during the remaining 8 hours, typically on the same schedule each day. For example, you can eat between 12:00 noon and 8:00 p.m. Two meals are advised which at best correspond to the above recommendation. From 8:00 p.m. to 12:00 noon the next day you are fasting. Don’t worry, during this time you don’t die of thirst! Within these 16 hours you are allowed to drink - best water, unsweetened drinks, juice drinks or tea. Further positive effects are attributed to intermittent fasting. 
Normalizing testosterone levels in case of basic diseases
Basic diseases which are causing too low testosterone levels must, of course, be treated under doctor supervision. Testosterone levels are raised by anabolic steroids (= synthetic testosterone analogues).
One of the relevant basic diseases is the so-called hypogonadism, which occurs most often in older people. It is treated by hormones prescribed by a medical specialist in the form of tablets, injections or special patches. Synthetic testosterone analogues are chemically modified so that their effect as a sex hormone is reduced. 
If low testosterone levels are measured and natural treatment is insufficient, it is treated in the form of a testosterone cure. Mostly, a basic disease is the reason for it. The testosterone cure is prescribed and supervised by a doctor. Testosterone can be prescribed in the form of tablets or injections. Injections need to be administered by a doctor. Every two to four weeks, 200 mg are injected. Oral drugs have a lower dosage. Tablets contain about 20 mg testosterone. During therapy, testosterone levels should be controlled regularly to adapt the dosage accordingly. 
Testosterone – Tablets
The intake of testosterone as e.g. anabolic steroids can lead to excess testosterone. Side effects in both men and women are not to be underestimated. Long-term consequences of anabolic steroids cannot be excluded. In general, it is not advisable to supplement testosterone without diagnosis. Otherwise, there is an increased risk of strokes. Studies observed the following side effects in study participants that supplemented testosterone though their hormone levels were sufficient: Acne, enlarged prostate and sleep apnoea (a temporary suspension of breathing during sleep). [5, 20, 21]
Conclusion: Testosterone should only be supplemented if a too low testosterone level was diagnosed.
High testosterone levels – Symptoms
Both men and women have testosterone in their bodies. In both genders, excess testosterone leads to different symptoms.
High testosterone levels – Causes
Testosterone levels in men and women can be too high when testosterone is supplied ‘from outside’ i.e. in the form of tablets, injections etc. (for example through doping drugs) or in case of a tumor of the adrenal gland. Cushing’s disease - which causes increased cortisol levels - can be another cause. In women, ovarian cysts and ovarian tumors as well as congenital hormone disorders of the adrenal cortex (adrenogenitale syndrome); in men, active testicular tumors can raise testosterone levels.
The androgen receptors
Defective androgen receptors can be another reason for excess testosterone. Receptors are protein complexes that bind signalling molecules to start certain reactions. Androgen receptors bind androgens such as testosterone to start the necessary reactions which influence masculine appearance and behaviour. 
Elevated testosterone levels in women cause disorders of the menstrual cycle, involuntary childlessness and hirsutism (typical male body hair) with acne and hair loss as well as masculinization. In men, the symptoms correspond to those of abuse of anabolic steroids.
High testosterone levels – Therapy
As excess testosterone is mostly caused by a disease, the underlying disease has to be treated. These include among others Cushing’s disease and tumor diseases. Therapy is based on drugs such as glucocorticoids, which are used mainly for Cushing’s disease. Women with too high testosterone values mostly are prescribed birth control pills which inhibit the body’s testosterone production. 
Testosterone – Values
Testosterone levels are highest in young adults and slowly decrease as of the age of 30 which is a natural change of the blood levels. According to studies, the value decreases by one percent every year. Therefore, you should keep an eye on your testosterone levels and not take testosterone tablets just by chance. 
Athletes should aim at higher levels as testosterone improves performance and stimulates protein metabolism for muscle growth. 
Testosterone levels - Chart
Hormones are subject to natural fluctuations. Therefore, no fixed reference value can be given. Instead, the blood levels should stay within a natural range. The following table shows you the normal ranges of testosterone values. The span of the optimal range in men is much bigger than in women as men have a lot more testosterone in their bodies than women. 
Guide: We created the following table as a guide. It shows the values measured in healthy German men:
Testosterone values change with age as the hormone production decreased as of the age of 30. Therefore, the range of measured values decreases from age group to age group.
Testosterone – Test
As of the age of 30, it is advisable for men to test their testosterone levels. As mentioned before, the body’s own production decreases with age: The risk of testosterone deficiency increases and various symptoms occur, which complicate everyday life. The female gender is also not spared from testosterone deficiency. Also in women, deficiency of the male sex hormone can lead to specific symptoms.
Good to know:
It is not recommended to measure your testosterone levels simply out of fear of deficiency. Excess testosterone can lead to health problems and mostly indicates an underlying disease.
What’s a testosterone test?
A testosterone test is used to determine your current testosterone levels. Testosterone is bound to certain proteins in blood and unbound (= active form) in saliva. Depending on the test, testosterone is either measured in your saliva or blood. It makes more sense to measure the active testosterone in saliva. The active form can be used completely by the whole body in contrast to the bound testosterone.
Some drugs (hormone preparations) influence the result, which must be taken into account for the measurement. The following graphics show a list of drugs which should be paused latest 4 days prior to the test execution. Please consult your physician first.
The cerascreen® Testosterone Test
The cerascreen® Testosterone Test is suitable for both men and women. The test measures the active form of testosterone in saliva. The test kit includes the equipment necessary for testing. For the analysis of your testosterone levels, you only need to fill three tubes with a small amount of saliva after getting up. Then you send the samples to our certified laboratory. After analysis, you receive a result report with comprehensive information and individual recommendations.
Use the test to achieve clarity about your testosterone levels and to protect your cardiovascular system.
How long does the testosterone test take?
The testosterone test is neither time-consuming nor complex. The cerascreen® Testosterone Test requires three saliva samples:
- right after getting up
- 30 minutes after getting up
- 1 hour after getting up
The saliva samples are sent to our specialist laboratory and evaluated by experts. Just a few days later, you receive the result report with comprehensive information.
The cerascreen® Testosterone Test in brief:
- determination of the level of free testosterone in your saliva
- sample taking from the comfort of your home
- analysis of free testosterone in saliva is a meaningful parameter
- three saliva samples are needed
- you receive a comprehensive result report with individual recommendations
Which doctors can do a testosterone test?
Should you be interested in an analysis of your testosterone levels by a doctor, please consult your family doctor. Apart from family doctors, you can also consult medical specialists such as urologists, endocrinologists or andrologists. Andrologists deal with male health, particularly relating to the problems of the male reproductive system, in which testosterone plays an essential role.
A personal interview about your medical history helps to clarify whether certain drugs are taken which influence testosterone metabolism. Furthermore, you are checked for the presence of acne, hair loss, body weight change and they examine your breast tissue. Women are checked for the presence of strong body hair. On the basis of your symptoms, the doctor normally takes a blood sample for analysis of your testosterone levels.
Testosterone and weight reduction
A multitude of studies currently evaluate hormones which play a role in weight reduction. One of the hormones, testosterone, also seems to play a major role in carbohydrate, fat and protein metabolism.
In protein metabolism, testosterone assures the production of proteins from the different amino acids. This confirms the role of this steroid hormone in muscle growth. Furthermore, testosterone in carbohydrate metabolism assures sugar (glucose) metabolism. In lipid metabolism, the hormone is contributing to the energy supply from fatty acids. 
Especially overweight people often suffer from testosterone deficiency. With increasing overweight, the risk of deficiency rises to up to 75 %. Studies show that hormone therapy in testosterone deficient patients - no matter which overweight rate they have - leads to weight loss WITHOUT yo-yo effect. Apart from weight reduction, the hip circumference was also reduced. [24–26]
Conclusion: In summary, it can be said that overweight people are a risk group for testosterone deficiency. It makes sense to rebalance testosterone values to reduce weight. It is not advisable to take testosterone supplements out of pure suspicion. Arbitrary supplementation may lead to a surplus. Hormonal balance reacts very sensitively to fluctuations which is why the surplus of a single hormone leads to further discrepancies in the entire system. Currently, a correlation between too high testosterone levels and high blood pressure, heart attacks and strokes is being discussed. In order to avoid wrong supplementation, the testosterone test can be used to provide evidence on the actual testosterone levels.
Testosterone and sports
In sport, various training goals can be pursued. Weight loss, endurance, muscle building and muscle definition are only some of the key factors to take into account in training. The anabolic hormone testosterone helps to increase your personal performance and to reach your goals. In conclusion, deficiency of this hormone can hamper the attainment of these objectives.
Testosterone and its muscle building effects
Testosterone is an anabolic steroid hormone. This means that it contributes to anabolic processes such as muscle growth. The steroid hormone stimulates the formation of muscle fibres and the production of proteins. Protein formation - thus the linking of several amino acids - is among others controlled by testosterone. 
During strength training, more testosterone is produced. Therefore, athletes mostly have higher testosterone levels than non-athletes. Moreover, it was found that testosterone levels in men increase sharper if their opponents radiate confidence of victory. This stimulates ambition which in turn increases hormone levels. 
Conclusion: You should carefully examine your testosterone levels to achieve your goals and to optimize performance. Sports can also contribute as it is raising testosterone levels. However, only strength exercise helps, whereas endurance sport has opposite effect.
Testosterone and cardiovascular diseases
With increasing age, the risk of cardiovascular diseases rises. Testosterone levels also change. This is why scientists assume a correlation between testosterone levels and cardiovascular diseases.  Below, we are explaining in how far testosterone and diseases of the cardiovascular system are correlating.
There are several risk factors for the occurrence of cardiovascular diseases. These include smoking, elevated blood lipids (cholesterol), high blood pressure and diabetes mellitus. These factors cause an increased deposition of plaques on the vascular walls (arteriosclerosis). The thicker they get, the more the blood vessel gets clogged up until they are finally blocked completely. This may result in heart attacks or strokes.
Newest state of knowledge
Testosterone is proven to have an effect on the heartbeat, for example by influencing muscle growth. Studies determined decreased blood pressure in case of optimal testosterone levels which in turn reduces the risk of heart attacks. 
In a study conducted in 2014, scientists also determined improved blood sugar and cholesterol values through optimization of testosterone levels. 
Conclusion: Optimal testosterone values can help to reduce three out of four risk factors for cardiovascular diseases.
Testosterone and hair loss
Men with bald head or constant hair loss which affects women can be caused by increased testosterone levels. Testosterone is transformed in the prostate and is present in skin, hair roots and prostate. The so-called dihydrotestosterone is, above all, associated with hair loss. However, genetics is paramount with regard to hair loss. If the hair roots are sensitive due to genetic disposition, dihydrotestosterone has an aggressive effect on the hair roots. This leads to severe hair loss. 
Conclusion: Hair loss occurs if the hair roots are sensitive to dihydrotestosterone
Testosterone and prostate cancer
According to recent studies, testosterone therapy does not increase the risk of prostate cancer and that relevant fears are unjustified. 
Testosterone therapy can, however, lead to prostate enlargement which above all affects the bladder. The enlargement is not equivalent to a cancerous disease. 
Conclusion: A therapy which includes large quantities of testosterone, does not increase the risk to develop prostate cancer.
- Testosterone is THE male sex hormone. However, women also have testosterone in their bodies.
- Testosterone is an anabolic steroid hormone which has building up effects and is above all produced in considerable quantities during puberty.
- Its functions include the appearance of visible gender characteristics, sperm formation, development of physique and muscles.
- As of the age of 30, testosterone production decreases.
Symptoms of testosterone deficiency are:
Lethargy, depression, decreased libido, osteoporosis, acne and hair loss.
Deficiency reasons can be:
Chronic diseases, inflammations, overweight and drug abuse.
Testosterone levels can be raised by:
Medicines, sports, weight reduction, vitamin D supplementation and a balanced diet rich in fibres, magnesium, zinc and selenium.
- Testosterone supplementation should not take place without medical supervision and authorization!
- Excess testosterone can be caused by doping, Cushing’s disease as well as tumor diseases and can lead to symptoms such as infertility, enlarged sex organs, hair loss, severe body hair, acne and mood swings.
- Optimal testosterone levels have positive effects on the risk of cardiovascular diseases and athletic performance.
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