Testosterone Levels in Men | The Ultimate Guide

Dr. Mike Jansen

Last Updated December 18, 2022

Dr. Mike Jansen

 December 18, 2022

What are healthy testosterone levels in men?

Inside this detailed guide, we’ll breakdown everything you MUST know about testosterone levels in men, including:

  • Normal testosterone levels
  • Free testosterone levels
  • Testosterone levels by age

…and so much more!…

Testosterone is one of the most important hormones in the human body.

If your testosterone levels are outside of the normal, healthy range then you may experience problems including reduced energy levels, impaired sexual function, reduced muscle mass, increased body fat, and even increased risk of cardiovascular disease.

Understanding and optimizing your own testosterone levels may be one of the most important things you can do to improve your health and overall quality of life.

Disclaimer: The contents of Testosterone.org are for informational and educational purposes. We do not provide legal advice. Likewise, we do not provide medical advice, diagnosis, or treatment. Please consult your physician prior to consuming any over-the-counter supplements, like a natural testosterone booster, and/or getting a prescription for a pharmaceutical medication. Your access to Testosterone.org is subject to our full disclaimer and terms of use.


What is Testosterone?

Testosterone is one of the most important hormones in the human body. It is known as the male sex hormone and is produced in the testicles in men. However, testosterone is also produced in smaller amounts in females.

Testosterone is responsible for regulating many different processes in the human body including muscle mass, body fat distribution, fertility, and red blood cell production. It is also responsible for giving males their secondary sexual characteristics including the development of facial hair and a deeper voice.

The truth is many men (and women) are suffering from low testosterone levels and they don’t even know it. Most men naturally start producing less testosterone around age 30.
This is sometimes called “menopause” and is a normal process of human aging. However, many men are now suffering from a condition called hypogonadism where the testes produce significantly less testosterone than they are supposed to.

Researchers have known for a while that men’s testosterone levels have been declining by about 1% per year every year sense the 1950s. One recent study showed that as much as 77% of men are suffering from some degree of hypogonadism [1]. Other studies show that hypogonadism is becoming more and more common with adult and even adolescent men [24]. This is a big deal because healthy testosterone levels are critical for optimal health.

Research has shown that there is a causal relationship between low testosterone levels and metabolic or cardiovascular disease [56]. This isn’t just an issue that is affecting sedentary individuals.

One recent study found that low testosterone levels in male firefighters was significantly associated with increased risk for cardiovascular disease and even liver disease [7]. Other problems with low testosterone levels include low bone density, reduced muscle mass and impaired sexual performance [811].

There are many different causes of low testosterone levels in men. Lifestyle factors, impaired hypothalamic function and testicular failure are three potential causes identified by researchers [1214]. The main takeaway here is that testosterone levels play a critical role in men’s (and women’s) overall health and well-being.

Low testosterone, or hypogonadism, is a serious medical condition that can lead to other health problems including metabolic disorders and cardiovascular disease. This is why it is so important to learn more about normal testosterone levels in men.


Testosterone Levels in Men


Normal Testosterone Levels in Men | Ultimate Guide

There are two main ways to measure testosterone in the human body: total testosterone and free testosterone. These two measurements are similar, but they also have some key differences that you must understand.

Your total testosterone level is the total amount of testosterone that is floating around in your bloodstream at any given time. Total testosterone is by far the most common way to measure someone’s testosterone levels. It gives you a very good idea of the amount of testosterone that is floating around in your body and exerting positive physiological effects.

So what are normal testosterone levels in men? Here is what you need to know:

The normal range for testosterone is about 300 – 1200 ng / dl, or nanograms per deciliter [1516]. Teenagers and adult men in their 20s and 30s usually fall in this range. However, most men start to produce less testosterone every year starting around age 30.

Here is a breakdown of normal testosterone levels for men of different ages:

  • Teenage males: 300 – 1200 ng / dL
  • Young adult men: 300 – 1200 ng / dL
  • Men in their 40s: 252 – 916 ng / dL
  • Men in their 50s: 215 – 878 ng / dL
  • Men in their 60s: 196 – 859 ng / dL
  • Men in their 70s: 156 – 819 ng / dL

Many recent studies show that the “reference values,” or normal testosterone ranges, for teenagers and adult men is closer to 250-800 ng / dl [1718]. The important thing to understand here is these studies are showing what is common in different populations, not necessarily what is normal.

Traditionally men’s total testosterone levels have been in the 300-1200 range. These values have been decreasing in recent years due to different factors including poor sleep patterns, reduced quality of food, increased stress levels and environmental toxins.

300 – 1200 ng / dl is a very wide range. Research shows that optimal testosterone levels for most men is in the 700 – 1070 ng / dl range [1516]. Some men naturally produce up to 1200 ng / dl of testosterone. However, this is the absolute upper limit for “natural” testosterone levels in adult men.

The normal upper limit is in the 700 – 1070 range. Under normal circumstances the only way to have total testosterone levels greater than 1200 ng / dl is through steroids and other performance enhancing drugs.

Anabolic steroids come with significant side effects including increased risk for cardiovascular disease and are not recommended for recreational use [19]. The human body is just not designed to handle supraphysiological levels of testosterone above 1200 ng / dl and this often comes with severe health consequences.

Unfortunately, some men suffer form a condition called hypogonadism, where they do not produce enough testosterone for optimal health. Studies have shown that men with total testosterone levels below 300 ng / dl usually experience symptoms of sexual dysfunction and other negative health conditions [20].


Free Testosterone Levels vs. Total Testosterone

There are two main tests for measuring testosterone in the body: total testosterone and free testosterone. These two tests may sound similar, but they have some significant differences from each other that you should be aware of.

Total testosterone is a measure of the total amount of testosterone that is circulating in your bloodstream. As we discussed earlier, total testosterone tends to fall in the 300 – 1200 ng / dl range for young adult males and teenagers. However, total testosterone does not tell the entire story.

The truth is only a small amount of the testosterone floating in your bloodstream is interacting with the rest of the cells in your body. Approximately 98% of the testosterone in your bloodstream is bound to either sex-hormone binding globulin (SHBG), or albumin. Your free testosterone is the 2% of testosterone that is not bound to a protein.

Overall, your free testosterone is even more important than total testosterone for most men.

Here is a breakdown of normal free testosterone levels in adult men [1516]:

  • Teenage males: 4.5-25.0 ng / dL
  • Young adult males: 4.5-25.0 ng / dL
  • Men in their 40s: 4.26 – 17.1 ng / dL
  • Men in their 50s: 3.87 – 15.6 ng / dL
  • Men in their 60s: 3.47 – 13.9 ng / dL
  • Men in their 70s: 3.28 – 13.0 ng / dL

It is very important that you test your total testosterone and free testosterone levels. Some individuals have conditions that cause them to produce a larger than normal amount of SHBG, or sex hormone binding globulin. This has the potential to lower your free testosterone levels, even if your total testosterone levels fall in the normal range.


Signs of Low Testosterone in Men

Low testosterone, or hypogonadism, is a serious medical condition. Individuals with low testosterone levels are at increased risk for many diseases and often experience a reduced quality of life.

Here are some of the biggest signs of low testosterone in men:

  • Reduced muscle mass [2122]
  • Male infertility and reduced sexual performance [2324]
  • Depression [2526]
  • Cognitive function [2728]
  • Diabetes, metabolic health and obesity [2930]
  • Impaired cardiovascular health [3132]

Reduced muscle mass is one of the most common symptoms of low testosterone levels. Low levels of muscle mass, or sarcopenia, can be a serious medical condition. Many research studies show that low muscle mass is associated with a reduced lifespan and overall quality of life.

Another common sign of low testosterone levels is male infertility and reduced sexual performance. Men require healthy testosterone levels to achieve and maintain an erection during sex.

Total testosterone levels below 300 ng / dL make this much more difficult to achieve. Many men also experience difficulty conceiving a child when their total testosterone levels are too low [2324]. Depression and reduced cognitive function are also quite common with reduced testosterone levels [2528]. Men with low testosterone levels often report feeling unmotivated in their life and in their work.

Finally, low testosterone levels are also associated with many chronic health conditions including diabetes, metabolic syndrome, obesity and even impaired cardiovascular health [2730]. In fact, men with low testosterone levels are at increased risk for heart attacks and strokes [3132].


How to Test Testosterone Levels

The only way to get an accurate measure of your current testosterone levels is to perform a blood test. There are many ways to do this: you can order a blood test through your doctor, or you can purchase a blood test through one of many online companies such as “Let’s Get Checked.”

You still have to visit a clinic to have your blood drawn but they save you the hassle of talking to your doctor to see if a blood test is appropriate for you. It is very important to pick the right blood test when you are trying to test your testosterone levels.

Here are the most important tests to include:

  • Total testosterone
  • Free testosterone
  • Estradiol

There are many other tests that you may want to include as part of your blood test to get a better idea of your overall health. Here are some of the most common tests that are included when testing testosterone levels:

  • Complete blood count
  • Comprehensive metabolic profile
  • Lipid profile
  • Thyroid profile

These tests will give you a better understanding of some different factors that may be influencing your testosterone levels.

For example, some people have a normal total testosterone but a reduced free testosterone. In these situations, additional testing may be required to better understand what may be causing your lower free testosterone levels.

Most online companies offer a simple men’s hormonal profile test that you can take. Of course, we recommend that you consult with your doctor or a qualified medical professional before testing your testosterone levels.

Get your hormone levels tested ASAP...


How to Increase Testosterone Levels Naturally

The truth is there are many ways to boost your testosterone levels naturally. Some of the most common recommendations include losing weight, exercising, and eating a well-balanced diet. However, there are some lesser-known strategies that you can use right now to start boosting your testosterone levels:

  • Sexual activity
  • Sleep
  • Vitamin D
  • Ecdysterone

According to research, one of the most effective strategies is to engage in sexual activity. Research shows that testosterone levels in men rise significantly following sex [33]. Other studies show that men’s testosterone levels can increase just by talking to a member of the opposite sex!

Another underrated strategy is to improve your sleep hygiene. Research shows that your testosterone plummets after just one night of reduced sleep [34]! This is something to keep in mind the next time you stay up past 2 am on a Friday night!

Of course, your nutrient status also plays a critical role in the amount of testosterone that your body naturally produces. Research shows there is a causal relationship between vitamin D levels and testosterone levels in men [35]. In other words, men with vitamin D levels in the higher end of the normal range produce significantly more testosterone than men who are deficient in this vital nutrient.

Finally, there are many natural substances that you can use to boost testosterone levels. One of the most popular natural testosterone boosters on the market today is called ecdysterone. This natural substance has been proven in numerous research studies to have a positive effect on testosterone levels and protein synthesis levels [3637].

Many users are reporting increased strength gains in the gym as well as rapid improvements in body composition. Here at Testosterone.org we recommend the ecdysterone supplement sold by Huge Supplements. Their ecdysterone product is manufactured in the United States under FDA regulated facilities so you know the quality of the product is high.


How to Increase Testosterone Levels with TRT

Testosterone replacement therapy is one of the most effective treatment options for men suffering from hypogonadism, or low testosterone levels. Testosterone therapy is designed to raise your total testosterone levels to the high end of the normal range (300 – 1200 ng / dL) so you an get all of the health and energy boosting benefits of optimal hormone levels.

With testosterone therapy you supplement the testosterone your body naturally produces with an external source of the hormone. Two of the most common delivery methods include injectable testosterone and testosterone gels that you rub directly on your skin.

Numerous meta-analyses have shown that testosterone replacement therapy is extremely safe when performed under the supervision of a doctor. In fact, testosterone therapy has been shown to have a positive impact on many health conditions including cardiovascular disease, type 2 diabetes and metabolic syndrome [3839].

Testosterone therapy is also extremely effective at raising low testosterone levels. This has been confirmed in many recent studies [4042]. Testosterone replacement therapy is a treatment option that can be considered by anyone who has been diagnosed with hypogonadism, or low testosterone levels.

Research shows that sexual function can be impaired when men’s total testosterone levels drop below 300 ng / dL. However, it is important to talk to your doctor to talk about whether testosterone therapy is the right choice for you.


Testosterone Levels in Men


The BEST Online TRT Clinic

Testosterone replacement therapy is one of the most popular treatment options for men with low testosterone levels. In fact, it is becoming more and more popular over time as testosterone levels continue to decline in the general population.

Some people are interested in testosterone replacement therapy, but do not like the idea of driving to a clinic and waiting in line to speak with their doctor. If this describes you then you may be interested in working with an online TRT clinic. The advantage of an online TRT clinic is you can talk to your doctor from your own home.

Your doctor will give you the chance to discuss the signs and symptoms that you are experiencing. If they agree that you may be suffering from low testosterone levels, then they will schedule an appointment for you with a lab test company.

Next your doctor will review the results of your test with you and explain the different treatment options that are available. One of our favorite online TRT clinics is called Fountain TRT. This company was founded Dr. Doron Stember, a board-certified urologist. Dr. Stember has treated thousands of men improve their lives with testosterone replacement therapy.

He uses a simple three-step process with all his patients:

  • Step #1: Take a free Low T assessment to see if you have symptoms of low testosterone
  • Step #2: Take a blood test with one of their partnered labs to determine your exact testosterone levels
  • Step #3: Talk to your telehealth doctor to talk about the treatment options that are available to address your Low T

If you and your Fountain TRT doctor decide that testosterone replacement therapy is right for you, then a prescription will be written, and your testosterone medication will be delivered right to your door.

Unlike other telehealth TRT providers, Fountain TRT exclusively uses a testosterone cream that you rub onto your shoulders. Testosterone creams are a great choice for anyone who does not want to deal with the pain or hassle of medical needles that are necessary with injectable forms of testosterone.

Get hormone therapy today with Fountain TRT...


Testosterone Levels in Men | Overall

Testosterone is one of the most important hormones in the human body. It plays a huge role in your overall health. Unfortunately, many men are suffering from low testosterone levels, and they don’t even know it.

Some of the unwanted side effects of low testosterone levels include reduced energy, reduced sexual function, depression, decreased muscle mass, increased body fat and even increased risk of cardiovascular disease.

There are two ways to measure testosterone levels: total testosterone and free testosterone. The normal range for total testosterone is 300 – 1200 ng / dL while the normal range for free testosterone is 4.5-25.0 ng / dL.

There are many ways to raise your testosterone levels, from “natural” strategies like optimizing your sleep to medical strategies like testosterone replacement therapy. For many people, an online TRT provider like Fountain TRT is a good option for addressing low testosterone levels.


 

References

  1. Millar AC, Lau ANC, Tomlinson G, Kraguljac A, Simel DL, Detsky AS, Lipscombe LL. Predicting low testosterone in aging men: a systematic review. CMAJ. 2016 Sep 20;188(13):E321-E330. doi: 10.1503/cmaj.150262. Epub 2016 Jun 20. PMID: 27325129; PMCID: PMC5026531.
  2. Liu YJ, Shen XB, Yu N, et al. Prevalence of late-onset hypogonadism among middle-aged and elderly males in China: results from a national survey. Asian J Androl. 2021;23(2):170-177. doi:10.4103/aja.aja_59_20
  3. Braga PC, Pereira SC, Ribeiro JC, Sousa M, Monteiro MP, Oliveira PF, Alves MG. Late-onset hypogonadism and lifestyle-related metabolic disorders. Andrology. 2020 Nov;8(6):1530-1538. doi: 10.1111/andr.12765. Epub 2020 Feb 16. PMID: 31991053.
  4. Cohen J, Nassau DE, Patel P, Ramasamy R. Low Testosterone in Adolescents & Young Adults [published correction appears in Front Endocrinol (Lausanne). 2020 Jul 14;11:449]. Front Endocrinol (Lausanne). 2020;10:916. Published 2020 Jan 10. doi:10.3389/fendo.2019.00916
  5. Peterson MD, Belakovskiy A, McGrath R, Yarrow JF. Testosterone Deficiency, Weakness, and Multimorbidity in Men. Sci Rep. 2018;8(1):5897. Published 2018 Apr 12. doi:10.1038/s41598-018-24347-6
  6. Saad F, Röhrig G, von Haehling S, Traish A. Testosterone Deficiency and Testosterone Treatment in Older Men. Gerontology. 2017;63(2):144-156. doi: 10.1159/000452499. Epub 2016 Nov 18. PMID: 27855417.
  7. Ranadive, S.M., Lofrano-Porto, A., Soares, E.M.K.V.K. et al. Low testosterone and cardiometabolic risks in a real-world study of US male firefighters. Sci Rep 11, 14189 (2021). https://doi.org/10.1038/s41598-021-93603-z
  8. Wong R.M.Y., Wong H., Zhang N., Chow S.K.H., Chau W.W., Wang J., Chim Y.N., Leung K.S., Cheung W.H. The relationship between sarcopenia and fragility fracture-a systematic review. Osteoporos. Int. 2019;30:541–553. doi: 10.1007/s00198-018-04828-0. – DOI – PubMed
  9. Harada N (2018) Role of androgens in energy metabolism affecting on body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity: lessons from a meta-analysis and rodent studies. Biosci Biotechnol Biochem 82(10):1667–1682.
  10. Naoki Harada, Role of androgens in energy metabolism affecting on body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity: lessons from a meta-analysis and rodent studies, Bioscience, Biotechnology, and Biochemistry, Volume 82, Issue 10, 3 October 2018, Pages 1667–1682, https://doi.org/10.1080/09168451.2018.1490172
  11. Liu ZY, Yang Y, Wen CY, Rong LM. Serum Osteocalcin and Testosterone Concentrations in Adult Males with or without Primary Osteoporosis: A Meta-Analysis. Biomed Res Int. 2017;2017:9892048. doi:10.1155/2017/9892048
  12. Swee DS, Gan EH. Late-Onset Hypogonadism as Primary Testicular Failure. Front Endocrinol (Lausanne). 2019;10:372. Published 2019 Jun 12. doi:10.3389/fendo.2019.00372
  13. Millar AC, Lau AN, Tomlinson G, et al. Predicting low testosterone in aging men: a systematic review. CMAJ 2016;188:E321–30.
  14. Golan R, Scovell JM, Ramasamy R. Age-related testosterone decline is due to waning of both testicular and hypothalamic-pituitary function. Aging Male. 2015;18(3):201-4. doi: 10.3109/13685538.2015.1052392. Epub 2015 Jun 15. PMID: 26075536; PMCID: PMC4816459.
  15. Bhasin S, Zhang A, Coviello A, Jasuja R, Ulloor J, Singh R, Vesper H, Vasan RS. The impact of assay quality and reference ranges on clinical decision making in the diagnosis of androgen disorders. Steroids. 2008 Dec 12;73(13):1311-7. doi: 10.1016/j.steroids.2008.07.003. Epub 2008 Jul 17. PMID: 18687348.
  16. Solberg HE, PetitClerc C. Approved recommendation (1988) on the theory of reference values. Part 3. Preparation of individuals and collection of specimens for the production of reference values. Clin Chim Acta. 1988 Oct 31;177(3):S3-11. doi: 10.1016/0009-8981(88)90074-5. PMID: 3233768.
  17. Snyder PJ, Bhasin S, Cunningham GR, Matsumoto AM, Stephens-Shields AJ, Cauley JA, Gill TM, Barrett-Connor E, Swerdloff RS, Wang C, Ensrud KE, Lewis CE, Farrar JT, Cella D, Rosen RC, Pahor M, Crandall JP, Molitch ME, Cifelli D, Dougar D, Fluharty L, Resnick SM, Storer TW, Anton S, Basaria S, Diem SJ, Hou X, Mohler ER 3rd, Parsons JK, Wenger NK, Zeldow B, Landis JR, Ellenberg SS; Testosterone Trials Investigators. Effects of Testosterone Treatment in Older Men. N Engl J Med. 2016 Feb 18;374(7):611-24. doi: 10.1056/NEJMoa1506119. PMID: 26886521; PMCID: PMC5209754.
  18. Basaria S, Harman SM, Travison TG, Hodis H, Tsitouras P, Budoff M, Pencina KM, Vita J, Dzekov C, Mazer NA, Coviello AD, Knapp PE, Hally K, Pinjic E, Yan M, Storer TW, Bhasin S. Effects of Testosterone Administration for 3 Years on Subclinical Atherosclerosis Progression in Older Men With Low or Low-Normal Testosterone Levels: A Randomized Clinical Trial. JAMA. 2015 Aug 11;314(6):570-81. doi: 10.1001/jama.2015.8881. PMID: 26262795.
  19. Albano GD, Amico F, Cocimano G, et al. Adverse Effects of Anabolic-Androgenic Steroids: A Literature Review. Healthcare (Basel). 2021;9(1):97. Published 2021 Jan 19. doi:10.3390/healthcare9010097
  20. https://www.health.harvard.edu/newsletter_article/testosterone_aging_and_the_mind
  21. Wong R.M.Y., Wong H., Zhang N., Chow S.K.H., Chau W.W., Wang J., Chim Y.N., Leung K.S., Cheung W.H. The relationship between sarcopenia and fragility fracture-a systematic review. Osteoporos. Int. 2019;30:541–553. doi: 10.1007/s00198-018-04828-0. – DOI – PubMed
  22. Harada N (2018) Role of androgens in energy metabolism affecting on body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity: lessons from a meta-analysis and rodent studies. Biosci Biotechnol Biochem 82(10):1667–1682.
  23. Leslie SW, Siref LE, Soon-Sutton TL, et al. Male Infertility. [Updated 2022 Feb 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562258/
  24. https://www.uptodate.com/contents/epidemiology-and-etiologies-of-male-sexual-dysfunction
  25. JBI Database of Systematic Reviews and Implementation Reports: September 2019 – Volume 17 – Issue 9 – p 1894-1900. doi: 10.11124/JBISRIR-2017-004035
  26. Zarrouf FA, Artz S, Griffith J, Sirbu C, Kommor M. Testosterone and depression: systematic review and meta-analysis. J Psychiatr Pract. 2009;15:289–305.
  27. Corona G, Guaraldi F, Rastrelli G, Sforza A, Maggi M. Testosterone Deficiency and Risk of Cognitive Disorders in Aging Males. World J Mens Health. 2021 Jan;39(1):9-18. doi: 10.5534/wjmh.200017. Epub 2020 Apr 1. PMID: 32378366; PMCID: PMC7752509.
  28. McHugh DJ, Root JC, Nelson CJ, Morris MJ. Androgen-deprivation therapy, dementia, and cognitive dysfunction in men with prostate cancer: How much smoke and how much fire?. Cancer. 2018;124(7):1326-1334. doi:10.1002/cncr.31153
  29. Wondimeneh Shibabaw Shiferaw, Tadesse Yirga Akalu, Pammla Margaret Petrucka, Habtamu Abera Areri, Yared Asmare Aynalem, Risk factors of erectile dysfunction among diabetes patients in Africa: A systematic review and meta-analysis, Journal of Clinical & Translational Endocrinology, 10.1016/j.jcte.2020.100232, 21, (100232), (2020).
  30. Lei Chen, Guang-rui Shi, Dan-dan Huang, Yang Li, Chen-chao Ma, Min Shi, Bin-xiao Su, Guang-jiang Shi, Male sexual dysfunction: A review of literature on its pathological mechanisms, potential risk factors, and herbal drug intervention, Biomedicine & Pharmacotherapy, 10.1016/j.biopha.2019.01.046, 112, (108585), (2019).
  31. Corona G, Rastrelli G, Di Pasquale G, Sforza A, Mannucci E, Maggi M. Endogenous Testosterone Levels and Cardiovascular Risk: Meta-Analysis of Observational Studies. J Sex Med. 2018 Sep;15(9):1260-1271. doi: 10.1016/j.jsxm.2018.06.012. Epub 2018 Aug 23. PMID: 30145097.
  32. Goodale T, Sadhu A, Petak S, Robbins R. Testosterone and the Heart. Methodist Debakey Cardiovasc J. 2017 Apr-Jun;13(2):68-72. doi: 10.14797/mdcj-13-2-68. PMID: 28740585; PMCID: PMC5512682.
  33. Vignozzi L, Corona G, Petrone L, Filippi S, Morelli AM, Forti G, Maggi M. Testosterone and sexual activity. J Endocrinol Invest. 2005;28(3 Suppl):39-44. PMID: 16042359.
  34. Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305(21):2173-2174. doi:10.1001/jama.2011.710
  35. Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann A. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 Mar;43(3):223-5. doi: 10.1055/s-0030-1269854. Epub 2010 Dec 10. PMID: 21154195.
  36. Isenmann E, Ambrosio G, Joseph JF, Mazzarino M, de la Torre X, Zimmer P, Kazlauskas R, Goebel C, Botrè F, Diel P, Parr MK. Ecdysteroids as non-conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans. Arch Toxicol. 2019 Jul;93(7):1807-1816. doi: 10.1007/s00204-019-02490-x. Epub 2019 May 23. PMID: 31123801.
  37. Parr MK, Botrè F, Naß A, Hengevoss J, Diel P, Wolber G. Ecdysteroids: A novel class of anabolic agents?. Biol Sport. 2015;32(2):169-173. doi:10.5604/20831862.1144420
  38. Bhasin S. Testosterone replacement in aging men: an evidence-based patient-centric perspective. J Clin Invest. 2021 Feb 15;131(4):e146607. doi: 10.1172/JCI146607. PMID: 33586676; PMCID: PMC7880314.
  39. Park HJ, Ahn ST, Moon DG. Evolution of Guidelines for Testosterone Replacement Therapy. J Clin Med. 2019 Mar 25;8(3):410. doi: 10.3390/jcm8030410. PMID: 30934591; PMCID: PMC6462962.
  40. Al-Zoubi RM, Yassin AA, Alwani M, Al-Qudimat A, Aboumarzouk OM, Zarour A, Al Ansari A. A systematic review on the latest developments in testosterone therapy: Innovations, advances, and paradigm shifts. Arab J Urol. 2021 Aug 8;19(3):370-375. doi: 10.1080/2090598X.2021.1959260. PMID: 34552788; PMCID: PMC8451690.
  41. Kim SH, Park JJ, Kim KH, Yang HJ, Kim DS, Lee CH, Jeon YS, Shim SR, Kim JH. Efficacy of testosterone replacement therapy for treating metabolic disturbances in late-onset hypogonadism: a systematic review and meta-analysis. Int Urol Nephrol. 2021 Sep;53(9):1733-1746. doi: 10.1007/s11255-021-02876-w. Epub 2021 Jun 5. PMID: 34089171.
  42. Lunenfeld B, Mskhalaya G, Zitzmann M, et al. Recommendations on the diagnosis, treatment and monitoring of hypogonadism in men. Aging Male. 2015;18(1):5-15. doi:10.3109/13685538.2015.100404
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