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Low Testosterone
•Last Updated: August 14, 2023
Low testosterone results from a problem in the testicles or the brain and can cause low libido, muscle loss, and/or depressed mood. It is primarily treated with testosterone replacement therapy.
Low Testosterone falls under theMen’s HealthandHealthy Aging & Longevitycategories.
Last Updated:August 14, 2023
Testosterone is the best-known androgen (i.e., male sex hormone). It is secreted by the testicles and is responsible for the development and maintenance of secondary male characteristics (e.g., increased body and facial hair, enlarged larynx, deep voice, muscularity). Low testosterone (i.e., hypogonadism) results from the failure of the testicles (i.e., the gonads) to produce normal levels of testosterone due to a problem within the hypothalamic-pituitary-testicular (HPT) axis.[1]
- Low sex drive
- Erectile dysfunction (i.e., the inability to get or keep an erection)
- Low sperm count
- Reduced muscle mass and strength and increased fat mass
- Low bone density (i.e., osteoporosis)
- Loss of body hair
- Gynaecomastia (i.e., enlargement of breast tissue)
- Sleep disturbances
- Reduced energy, depressed mood, and trouble concentrating
Testosterone levels are assessed using a blood test. The cutoff for low testosterone differs between organizations, but most define it as a total testosterone level of <231–275 ng/dL.[2] Testosterone levels should be assessed early in the morning (between 7–11 a.m.) when peak levels occur, and in a fasted state. Two separate low testosterone measurements (preferably four weeks apart) along with clinical signs and symptoms of low testosterone are needed to be diagnosed with low testosterone.
Testosterone replacement therapy (TRT) is the primary treatment option for low testosterone and can be given as an oral pill, buccal tablet (which dissolves in the mouth), injection, nasal gel, topical gel, transdermal patch (worn on the skin), or implant.[1] TRT appears to be safe,[3] although there is limited data on long-term safety.
Each form of administration can cause unique adverse effects, but in general, TRT may cause erythrocytosis (as indicated by a hematocrit level > 54%), dyslipidemia, acne, oily skin, reduced sperm production, and/or growth of metastatic prostate cancer.[1][4] Additionally, TRT is contraindicated for certain populations (e.g., people with a recent history of heart attack or stroke, heart failure, or prostate cancer).[1]
A long list of supplements are marketed as testosterone boosters, but there is scant evidence to suggest that any of them affect testosterone levels.[5][6] Some of the more popular options include saw-palmetto, ashwagandha, tribulus-terrestris, fenugreek, d-aspartic-acid, maca, horny-goat-weed, and boron.
Supplementing with certain nutrients such as vitamin D, zinc, and magnesium can slightly increase testosterone levels if dietary intake and serum levels are inadequate.[7]
In many men low testosterone is caused by reversible conditions, such as excess body fat and chronic disease (e.g., type-2-diabetes, metabolic-syndrome). Consequently, a hypocaloric diet is very effective for increasing testosterone levels in this population,[8] whereas a hypocaloric diet seems to reduce testosterone levels in lean men.[9][10]
In addition, it’s worth paying attention to dietary fat levels, because limited evidence suggests that low-fat diets (≤25% of energy intake) decrease testosterone levels compared to higher-fat diets (about 40% of energy intake).[11]
Exercise — whether it’s aerobic exercise, high-intensity interval training, or resistance training — increases testosterone levels,[12] especially when it’s included as part of a lifestyle intervention to reduce body weight.[13] Exercise may also improve the effectiveness of TRT.[14] Bariatric surgery is another effective method for increasing testosterone levels in men with obesity.[15]
The cause of low testosterone is classified as either primary or secondary and further categorized as functional or organic. Primary hypogonadism originates from a problem in the testicles, while secondary hypogonadism indicates a problem in the hypothalamus or the pituitary gland, which are the parts of the brain that signal the testicles to produce testosterone.[1]
Functional hypogonadism is caused by factors that suppress testosterone levels (e.g., medications, obesity, type 2 diabetes, aging, excessive exercise, malnutrition) but are potentially reversible, while organic hypogonadism is caused by a congenital, structural, or destructive condition (e.g., Klinefelter syndrome, Kallmann syndrome, hemochromatosis, inflammatory disease, injury to the testicles, traumatic brain injury, chemotherapy or radiation) that results in largely irreversible hypothalamic, pituitary, or testicular dysfunction.[1]
Looking for a Supplement guide?
Our Supplement Guides give you unbiased research-based recommendations that you can immediately apply to improve your health. Low Testosterone is related to the following Supplement Guides:Research FeedRead all studies
When it comes to increasing your testosterone, quality sleep, physical activity, and weight management come first. A few supplements can help sustain healthy testosterone levels, but most supplements marketed as testosterone boosters don't work, though some can make you believe they do by boosting your libido.
Testosterone is an androgen, a male sex hormone, though women need it too. In men, low testosterone has been associated with low libido[59] and poor health outcomes, such as the development of metabolic syndrome.[60] In men and women, low testosterone has been associated with depression.[61][62]
Middle-aged[25] and older[26] men see their testosterone levels decrease by 0.4% to 1.6% per year, and many are the men who experience lower-than-average levels even in their 30s.[27] Fortunately, quality sleep, physical activity, weight management, magnesium, zinc, and vitamin D can all help sustain healthy testosterone levels.
Lifestyle
To optimize your testosterone levels, you don’t only need the proper amounts of vitamins and minerals; you also need to sleep well, exercise, and keep a healthy weight.
1. Sleep
Lack of sleep causes numerous health issues. Notably, it decreases testosterone production[63][64][65][66][67] and facilitates fat gain[68] (and we’ll see that fat gain itself can impair testosterone production). Getting enough quality sleep is so important that we will be publishing an article on that soon.
2. Physical activity
Resistance training can raise testosterone levels for 15–30 minutes post-exercise.[16][17] More importantly, it can benefit testosterone production in the long run by improving body composition and reducing insulin resistance.[16]
Overtraining, however, is counterproductive. Prolonged endurance exercise especially can cause your testosterone to drop.[18][19] Ensuring adequate recovery time will help you receive the full benefits of physical activity.
3. Weight management
Weight gain and the associated chronic diseases, such as cardiovascular disease and type 2 diabetes,[21][22][23] are strongly linked to decreases in testosterone, particularly in middle-aged and older men.
If you gain weight (as fat), your testosterone production drops. Fortunately, if you lose weight, your testosterone production can climb back up.
Adapted from Grossmann and Matsumoto. J Clin Endocrinol Metab. 2017.[8]
As this figure shows, observational studies have seen consistent results: in people who are overweight or obese, the greater the weight loss, the greater the testosterone increase.[21]
These results have been echoed in clinical trials. A meta-analysis of 24 RCTs looked at weight loss caused by diet or bariatric surgery:[15] In the diet studies, the average 9.8% weight loss was linked to a testosterone increase of 2.9 nmol/L (84 ng/dL). In the bariatric-surgery studies, the average 32% weight loss was linked to a testosterone increase of 8.7 nmol/L (251 ng/dL).
You need not lose huge amounts of weight to see a bump in testosterone levels, either: a 5% loss in weight can increase total testosterone by 2 nmol/L (58 ng/dL).[24]
Quality sleep, physical activity, and weight management support healthy testosterone levels, and they’re synergistic: If you lack sleep, you find it harder to exercise and easier to gain fat. If you exercise, you find it easier to sleep and to keep a healthy weight. If your weight is healthy, you find it easier to exercise and easier to sleep.
If you want to know more about the lifestyle-testosterone connection, check out our infographic and article here.
Supplements
Only a few supplements have been shown to benefit testosterone production. Among those, the evidence mostly supports vitamin D and zinc, followed by magnesium. Two caveats should be kept in mind, however:
-
Supplementing with a vitamin or mineral is likely to help you only if you suffer from a deficiency or an insufficiency in this vitamin or mineral.
-
Correcting a deficiency or an insufficiency is more likely to raise your testosterone levels if they are low.
1. Vitamin D
Vitamin D helps regulate testosterone levels.[69][70] Ideally, you would produce all the vitamin D you need through sunlight exposure, but if you live far from the equator, have dark skin, or simply spend most of your time inside, you may need to complement your own production with the help of foods or supplements.
Serum 25(OH)D concentrations
In Canada and the United States, the Recommended Daily Allowance (RDA) for vitamin D falls between 400 and 800 IU (International Units).[71] These amounts, which have been criticized as too low by some,[72][73] are attainable from only a few food sources, which is why vitamin D has become a popular supplement.
| AGE | MALE | FEMALE | PREGNANT | LACTATING |
|---|---|---|---|---|
| 0–12 months | 400** | 400** | — | — |
| 1–13 years | 600 | 600 | — | — |
| 14–18 years | 600 | 600 | 600 | 600 |
| 19–50 years | 600 | 600 | 600 | 600 |
| 51–70 years | 600 | 600 | — | — |
| >70 years | 800 | 800 | — | — |
* 40 IU = 1 mcg | ** Adequate intake (AI)
Reference: Institute of Medicine. Dietary Reference Intakes for Adequacy: Calcium and Vitamin D (chapter 5 in Dietary Reference Intakes for Calcium and Vitamin D. The National Academies Press. 2011. DOI:10.17226/13050)
2. Zinc
Zinc deficiency can hinder testosterone production.[74][75] Like magnesium, zinc is lost through sweat,[76] so athletes and other people who sweat a lot are more likely to be deficient. Although dietary zinc is mostly found in animal products, zinc-rich foods include some grains and nuts.
| AGE | MALE | FEMALE | PREGNANT | LACTATING |
|---|---|---|---|---|
| 0–6 months | 2* | 2* | — | — |
| 7–12 months | 3 | 3 | — | — |
| 1–3 years | 3 | 3 | — | — |
| 4–8 years | 5 | 5 | — | — |
| 9–13 years | 8 | 8 | — | — |
| 14–18 years | 11 | 9 | 12 | 13 |
| 19+ years | 11 | 8 | 11 | 12 |
* Adequate Intake (AI) Reference: Institute of Medicine. Zinc (chapter 12 in Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. The National Academies Press. 2001. DOI:10.17226/10026)
Consuming much more than your RDA[77] can be harmful. In the short term, high doses can cause nausea[78] and vomiting.[79] In the long term, they can lead to a copper deficiency.[80][81]
3. Magnesium
In males with low magnesium levels and low testosterone levels, an increase in magnesium intake can translate into an increase in testosterone production,[82] both directly and (since one of magnesium’s functions in your body is to help convert vitamin D into its active form[83]) indirectly.
While more common in the older population,[84] magnesium deficiency isn’t unknown in younger people (notably athletes,[85] since, link zinc, magnesium is lost through sweat[76][86][87]). Yet getting your RDA should be easy: magnesium-rich foods are numerous and can fit all kinds of diets.
| AGE | MALE | FEMALE | PREGNANT | LACTATING |
|---|---|---|---|---|
| 0–6 months | 30* | 30* | — | — |
| 7–12 months | 75* | 75* | — | — |
| 1–3 years | 80 | 80 | — | — |
| 4–8 years | 130 | 130 | — | — |
| 9–13 years | 240 | 240 | — | — |
| 14–18 years | 410 | 360 | 400 | 360 |
| 19-30 years | 400 | 310 | 350 | 310 |
| 31–50 years | 420 | 320 | 360 | 320 |
| >51 years | 420 | 320 | — | — |
* Adequate intake (AI)
Reference: Institute of Medicine. Magnesium (chapter 6 in Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academies Press. 1997. [88])
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,[89] and humans only 4% in another[90]) and can cause intestinal discomfort and diarrhea.
Overhyped supplements
Numerous products are advertised as testosterone boosters, but the vast majority don’t work, though some can make you believe they do by boosting your libido. Maca, for instance, can enhance libido without affecting testosterone.[91][92][93][94]
Maybe the most popular “testosterone booster” is D-aspartic acid (DAA, or D-aspartate). DAA did increase testosterone levels in two studies, one that used 2.66 g/day[95] and the other 3.12 g/day,[96] but two later studies found no increase with 3 g/day,[97][98] and the latest even noted a decrease with 6 g/day.[97]
Eat a healthy, balanced diet, so as to avoid nutritional deficiencies. If your testosterone levels are low, pay attention to your intakes of vitamin D, zinc, and magnesium. Be skeptical of supplements marketed as testosterone boosters; there’s a good chance the only thing these supplements will boost is their manufacturers’ bottom lines.
Bottom line
The interventions discussed in this article will work best for men with low testosterone, but they can also help men with normal testosterone to sustain their levels, year after year.
Supplements can help, but they can’t replace a healthy lifestyle. In order to optimize your testosterone production, make sure you get enough quality sleep on a daily basis, incorporate some resistance training into your workout program, and monitor your weight.
Try to get enough vitamin D, zinc, and magnesium through your diet. However, if dietary changes prove insufficient, supplementation can help make up the difference.
Not all testosterone deficiencies can be fixed through lifestyle or supplement interventions. It may be prudent to speak with your doctor if the options discussed above do not yield sufficient results.
- ^Shalender Bhasin, Juan P Brito, Glenn R Cunningham, Frances J Hayes, Howard N Hodis, Alvin M Matsumoto, Peter J Snyder, Ronald S Swerdloff, Frederick C Wu, Maria A YialamasTestosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice GuidelineJ Clin Endocrinol Metab.(2018 May 1)
- ^Kwong JCC, Krakowsky Y, Grober ETestosterone Deficiency: A Review and Comparison of Current Guidelines.J Sex Med.(2019-Jun)
- ^Diem SJ, Greer NL, MacDonald R, McKenzie LG, Dahm P, Ercan-Fang N, Estrada A, Hemmy LS, Rosebush CE, Fink HA, Wilt TJEfficacy and Safety of Testosterone Treatment in Men: An Evidence Report for a Clinical Practice Guideline by the American College of Physicians.Ann Intern Med.(2020-01-21)
- ^Chrysant SGControversies regarding the cardiovascular effects of testosterone replacement therapy in older men.Drugs Today (Barc).(2018-Jan)
- ^Balasubramanian A, Thirumavalavan N, Srivatsav A, Yu J, Lipshultz LI, Pastuszak AWTestosterone Imposters: An Analysis of Popular Online Testosterone Boosting Supplements.J Sex Med.(2019-02)
- ^Clemesha CG, Thaker H, Samplaski MK'Testosterone Boosting' Supplements Composition and Claims Are not Supported by the Academic Literature.World J Mens Health.(2020-Jan)
- ^Zamir A, Ben-Zeev T, Hoffman JRManipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations.Nutrients.(2021-Sep-25)
- ^Grossmann M, Matsumoto AMA Perspective on Middle-Aged and Older Men With Functional Hypogonadism: Focus on Holistic ManagementJ Clin Endocrinol Metab.(2017 Mar 1)
- ^Stephen J Smith, Shaun Y M Teo, Adrian L Lopresti, Brody Heritage, Timothy J FairchildExamining the effects of calorie restriction on testosterone concentrations in men: a systematic review and meta-analysisNutr Rev.(2021 Oct 6)
- ^Cangemi R, Friedmann AJ, Holloszy JO, Fontana LLong-term effects of calorie restriction on serum sex-hormone concentrations in men.Aging Cell.(2010-Apr)
- ^Joseph Whittaker, Kexin WuLow-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studiesJ Steroid Biochem Mol Biol.(2021 Jun)
- ^Zouhal H, Jayavel A, Parasuraman K, Hayes LD, Tourny C, Rhibi F, Laher I, Abderrahman AB, Hackney ACEffects of Exercise Training on Anabolic and Catabolic Hormones with Advanced Age: A Systematic Review.Sports Med.(2022-06)
- ^Corona G, Rastrelli G, Morelli A, Sarchielli E, Cipriani S, Vignozzi L, Maggi MTreatment of Functional Hypogonadism Besides Pharmacological Substitution.World J Mens Health.(2020-Jul)
- ^Cho DY, Yeo JK, Cho SI, Jung JE, Yang SJ, Kong DH, Ha JK, Kim JG, Park MGExercise improves the effects of testosterone replacement therapy and the durability of response after cessation of treatment: a pilot randomized controlled trial.Asian J Androl.(2017)
- ^Corona G, Rastrelli G, Monami M, Saad F, Luconi M, Lucchese M, Facchiano E, Sforza A, Forti G, Mannucci E, Maggi MBody weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysisEur J Endocrinol.(2013 May 2)
- ^O'Leary CB, Hackney ACAcute and chronic effects of resistance exercise on the testosterone and cortisol responses in obese males: a systematic reviewPhysiol Res.(2014)
- ^Kraemer WJ, Ratamess NAHormonal responses and adaptations to resistance exercise and trainingSports Med.(2005)
- ^Daly W, Seegers CA, Rubin DA, Dobridge JD, Hackney ACRelationship between stress hormones and testosterone with prolonged endurance exerciseEur J Appl Physiol.(2005 Jan)
- ^Hackney AC, Aggon EChronic Low Testosterone Levels in Endurance Trained Men: The Exercise- Hypogonadal Male ConditionJ Biochem Physiol.(2018)
- ^Vingren JL, Kraemer WJ, Ratamess NA, Anderson JM, Volek JS, Maresh CMTestosterone physiology in resistance exercise and training: the up-stream regulatory elementsSports Med.(2010 Dec 1)
- ^Grossmann MLow testosterone in men with type 2 diabetes: significance and treatmentJ Clin Endocrinol Metab.(2011 Aug)
- ^Tajar A, Forti G, O'Neill TW, Lee DM, Silman AJ, Finn JD, Bartfai G, Boonen S, Casanueva FF, Giwercman A, Han TS, Kula K, Labrie F, Lean ME, Pendleton N, Punab M, Vanderschueren D, Huhtaniemi IT, Wu FC, EMAS GroupCharacteristics of secondary, primary, and compensated hypogonadism in aging men: evidence from the European Male Ageing StudyJ Clin Endocrinol Metab.(2010 Apr)
- ^Hall SA, Esche GR, Araujo AB, Travison TG, Clark RV, Williams RE, McKinlay JBCorrelates of low testosterone and symptomatic androgen deficiency in a population-based sampleJ Clin Endocrinol Metab.(2008 Oct)
- ^Camacho EM, Huhtaniemi IT, O'Neill TW, Finn JD, Pye SR, Lee DM, Tajar A, Bartfai G, Boonen S, Casanueva FF, Forti G, Giwercman A, Han TS, Kula K, Keevil B, Lean ME, Pendleton N, Punab M, Vanderschueren D, Wu FC, EMAS GroupAge-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing StudyEur J Endocrinol.(2013 Feb 20)
- ^Feldman HA, Longcope C, Derby CA, Johannes CB, Araujo AB, Coviello AD, Bremner WJ, McKinlay JBAge trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts male aging studyJ Clin Endocrinol Metab.(2002 Feb)
- ^Wu FC, Tajar A, Pye SR, Silman AJ, Finn JD, O'Neill TW, Bartfai G, Casanueva F, Forti G, Giwercman A, Huhtaniemi IT, Kula K, Punab M, Boonen S, Vanderschueren D, European Male Aging Study GroupHypothalamic-pituitary-testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging StudyJ Clin Endocrinol Metab.(2008 Jul)
- ^Handelsman DJ, Yeap B, Flicker L, Martin S, Wittert GA, Ly LPAge-specific population centiles for androgen status in menEur J Endocrinol.(2015 Dec)
- ^Anna L Goldman, Shalender Bhasin, Frederick C W Wu, Meenakshi Krishna, Alvin M Matsumoto, Ravi JasujaA Reappraisal of Testosterone's Binding in Circulation: Physiological and Clinical ImplicationsEndocr Rev.(2017 Aug 1)
- ^van der Merwe J, Brooks NE, Myburgh KHThree weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby playersClin J Sport Med.(2009 Sep)
- ^Vatani DS, Faraji H, Soori R, Mogharnasi RThe Effects of Creatine Supplementation on Performance and Hormonal Response in Amateur SwimmersScience and Sports.(2011 Nov)
- ^Arazi H, Rahmaninia F, Hosseini K, Asadi AEffects of short term creatine supplementation and resistance exercises on resting hormonal and cardiovascular responsesScience and Sports.(2015 Apr)
- ^Cooke MB, Brabham B, Buford TW, Shelmadine BD, McPheeters M, Hudson GM, Stathis C, Greenwood M, Kreider R, Willoughby DSCreatine supplementation post-exercise does not enhance training-induced adaptations in middle to older aged malesEur J Appl Physiol.(2014 Jun)
- ^Cook CJ, Crewther BT, Kilduff LP, Drawer S, Gaviglio CMSkill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trialJ Int Soc Sports Nutr.(2011 Feb 16)
- ^Crowe MJ, O'Connor DM, Lukins JEThe effects of beta-hydroxy-beta-methylbutyrate (HMB) and HMB/creatine supplementation on indices of health in highly trained athletesInt J Sport Nutr Exerc Metab.(2003 Jun)
- ^Hoffman J, Ratamess N, Kang J, Mangine G, Faigenbaum A, Stout JEffect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletesInt J Sport Nutr Exerc Metab.(2006 Aug)
- ^Eijnde BO, Hespel PShort-term creatine supplementation does not alter the hormonal response to resistance trainingMed Sci Sports Exerc.(2001 Mar)
- ^Volek JS, Ratamess NA, Rubin MR, Gómez AL, French DN, McGuigan MM, Scheett TP, Sharman MJ, Häkkinen K, Kraemer WJThe effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreachingEur J Appl Physiol.(2004 May)
- ^Faraji H, Arazi H, Vatani D, Hakimi MThe effects of creatine supplementation on sprint running performance and selected hormonal responsesSAJRSPER.(2010)
- ^Rahimi R, Faraji H, Vatani DS, Qaderi MCreatine supplementation alters the hormonal response to resistance exerciseKinesiology.(2010)
- ^Volek JS, Boetes M, Bush JA, Putukian M, Sebastianelli W, Wayne J, Kraemer, WJResponse of Testosterone and Cortisol Concentrations to High-Intensity Resistance Exercise Following Creatine SupplementationJSCR.(1997 Ayg)
- ^Zahra Kiasalari, Mohsen Khalili, Mahbobeh AghaeiEffect of withania somnifera on levels of sex hormones in the diabetic male ratsInternational Journal of Reproductive Biomed.(2009)
- ^Ahmad MK, Mahdi AA, Shukla KK, Islam N, Rajender S, Madhukar D, Shankhwar SN, Ahmad SWithania somnifera improves semen quality by regulating reproductive hormone levels and oxidative stress in seminal plasma of infertile malesFertil Steril.(2010 Aug)
- ^Abbas Ali Mahdi, Kamla Kant Shukla, Mohammad Kaleem Ahmad, Singh Rajender, Satya Narain Shankhwar, Vishwajeet Singh, Deepansh DalelaWithania somnifera Improves Semen Quality in Stress-Related Male FertilityEvid Based Complement Alternat Med.(2009 Sep 29)
- ^Wankhede S, Langade D, Joshi K, Sinha SR, Bhattacharyya SExamining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trialJ Int Soc Sports Nutr.(2015 Nov 25)
- ^Exton MS, Krüger TH, Bursch N, Haake P, Knapp W, Schedlowski M, Hartmann UEndocrine response to masturbation-induced orgasm in healthy men following a 3-week sexual abstinenceWorld J Urol.(2001 Nov)
- ^Jiang M, Xin J, Zou Q, Shen JWA research on the relationship between ejaculation and serum testosterone level in menJ Zhejiang Univ Sci.(2003 Mar-Apr)
- ^Krüger T, Exton MS, Pawlak C, von zur Mühlen A, Hartmann U, Schedlowski MNeuroendocrine and cardiovascular response to sexual arousal and orgasm in menPsychoneuroendocrinology.(1998 May)
- ^Krüger TH, Haake P, Chereath D, Knapp W, Janssen OE, Exton MS, Schedlowski M, Hartmann USpecificity of the neuroendocrine response to orgasm during sexual arousal in menJ Endocrinol.(2003 Apr)
- ^Krüger TH, Haake P, Haverkamp J, Krämer M, Exton MS, Saller B, Leygraf N, Hartmann U, Schedlowski MEffects of acute prolactin manipulation on sexual drive and function in malesJ Endocrinol.(2003 Dec)
- ^Krüger TH, Haake P, Hartmann U, Schedlowski M, Exton MSOrgasm-induced prolactin secretion: feedback control of sexual driveNeurosci Biobehav Rev.(2002 Jan)
- ^Stahl SMThe psychopharmacology of sex, Part 1: Neurotransmitters and the 3 phases of the human sexual responseJ Clin Psychiatry.(2001 Feb)
- ^Motofei IG, Rowland DLNeurophysiology of the ejaculatory process: developing perspectivesBJU Int.(2005 Dec)
- ^Pharmacotherapy for Premature Ejaculation
- ^Assessment of erectogenic properties of apomorphine and yohimbine in man
- ^McMahon CGTreatment of premature ejaculation with sertraline hydrochloride: a single-blind placebo controlled crossover studyJ Urol.(1998 Jun)
- ^McMahon CG, Samali RPharmacological treatment of premature ejaculationCurr Opin Urol.(1999 Nov)
- ^Krüger TH, Hartmann U, Schedlowski MProlactinergic and dopaminergic mechanisms underlying sexual arousal and orgasm in humansWorld J Urol.(2005 Jun)
- ^Passie T, Hartmann U, Schneider U, Emrich HM, Krüger THEcstasy (MDMA) mimics the post-orgasmic state: impairment of sexual drive and function during acute MDMA-effects may be due to increased prolactin secretionMed Hypotheses.(2005)
- ^Travison TG, Morley JE, Araujo AB, O'Donnell AB, McKinlay JBThe relationship between libido and testosterone levels in aging menJ Clin Endocrinol Metab.(2006 Jul)
- ^Chrysohoou C, Panagiotakos D, Pitsavos C, Siasos G, Oikonomou E, Varlas J, Patialiakas A, Lazaros G, Psaltopoulou T, Zaromitidou M, Kourkouti P, Tousoulis D, Stefanadis CLow total testosterone levels are associated with the metabolic syndrome in elderly men: the role of body weight, lipids, insulin resistance, and inflammation; the Ikaria studyRev Diabet Stud.(2013 Spring)
- ^Westley CJ, Amdur RL, Irwig MSHigh Rates of Depression and Depressive Symptoms among Men Referred for Borderline Testosterone LevelsJ Sex Med.(2015 Aug)
- ^Giltay EJ, Enter D, Zitman FG, Penninx BW, van Pelt J, Spinhoven P, Roelofs KSalivary testosterone: associations with depression, anxiety disorders, and antidepressant use in a large cohort studyJ Psychosom Res.(2012 Mar)
- ^Cote KA, McCormick CM, Geniole SN, Renn RP, MacAulay SDSleep deprivation lowers reactive aggression and testosterone in menBiol Psychol.(2013 Feb)
- ^Leproult R, Van Cauter EEffect of 1 week of sleep restriction on testosterone levels in young healthy menJAMA.(2011 Jun 1)
- ^Penev PDAssociation between sleep and morning testosterone levels in older menSleep.(2007 Apr)
- ^González-Santos MR, Gajá-Rodríguez OV, Alonso-Uriarte R, Sojo-Aranda I, Cortés-Gallegos VSleep deprivation and adaptive hormonal responses of healthy menArch Androl.(1989)
- ^Cortés-Gallegos V, Castañeda G, Alonso R, Sojo I, Carranco A, Cervantes C, Parra ASleep deprivation reduces circulating androgens in healthy menArch Androl.(1983 Mar)
- ^Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, Penev PDInsufficient sleep undermines dietary efforts to reduce adiposityAnn Intern Med.(2010 Oct 5)
- ^Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann AEffect of vitamin D supplementation on testosterone levels in menHorm Metab Res.(2011 Mar)
- ^Wehr E, Pilz S, Boehm BO, März W, Obermayer-Pietsch BAssociation of vitamin D status with serum androgen levels in menClin Endocrinol (Oxf).(2010 Aug)
- ^Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, A Catharine Ross, Christine L Taylor, Ann L Yaktine, Heather B Del ValleDietary Reference Intakes for Calcium and Vitamin D
- ^Heaney R, Garland C, Baggerly C, French C, Gorham ELetter to Veugelers, P.J. and Ekwaru, J.P., A statistical error in the estimation of the recommended dietary allowance for vitamin D. Nutrients 2014, 6, 4472-4475; doi:10.3390/nu6104472Nutrients.(2015 Mar 10)
- ^Veugelers PJ, Ekwaru JPA statistical error in the estimation of the recommended dietary allowance for vitamin DNutrients.(2014 Oct 20)
- ^Netter A, Hartoma R, Nahoul KEffect of zinc administration on plasma testosterone, dihydrotestosterone, and sperm countArch Androl.(1981 Aug)
- ^Chang CS, Choi JB, Kim HJ, Park SBCorrelation between serum testosterone level and concentrations of copper and zinc in hair tissueBiol Trace Elem Res.(2011 Dec)
- ^Tang YM, Wang DG, Li J, Li XH, Wang Q, Liu N, Liu WT, Li YXRelationships between micronutrient losses in sweat and blood pressure among heat-exposed steelworkersInd Health.(2016 Jun 10)
- ^Institute of Medicine (US) Panel on MicronutrientsDietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
- ^Singh M, Das RRZinc for the common coldCochrane Database Syst Rev.(2011 Feb 16)
- ^Valentiner-Branth P, Shrestha PS, Chandyo RK, Mathisen M, Basnet S, Bhandari N, Adhikari RK, Sommerfelt H, Strand TAA randomized controlled trial of the effect of zinc as adjuvant therapy in children 2-35 mo of age with severe or nonsevere pneumonia in Bhaktapur, NepalAm J Clin Nutr.(2010 Jun)
- ^Willis MS, Monaghan SA, Miller ML, McKenna RW, Perkins WD, Levinson BS, Bhushan V, Kroft SHZinc-induced copper deficiency: a report of three cases initially recognized on bone marrow examinationAm J Clin Pathol.(2005 Jan)
- ^Afrin LBFatal copper deficiency from excessive use of zinc-based denture adhesiveAm J Med Sci.(2010 Aug)
- ^Maggio M, De Vita F, Lauretani F, Nouvenne A, Meschi T, Ticinesi A, Dominguez LJ, Barbagallo M, Dall'aglio E, Ceda GPThe Interplay between Magnesium and Testosterone in Modulating Physical Function in MenInt J Endocrinol.(2014)
- ^Uwitonze AM, Razzaque MSRole of Magnesium in Vitamin D Activation and FunctionJ Am Osteopath Assoc.(2018 Mar 1)
- ^Costello RB, Moser-Veillon PBA review of magnesium intake in the elderly. A cause for concern?Magnes Res.(1992 Mar)
- ^Nielsen FH, Lukaski HCUpdate on the relationship between magnesium and exerciseMagnes Res.(2006 Sep)
- ^Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Washington (DC)Nutritional Needs in Hot Environments, “Influence of Exercise and Heat on Magnesium Metabolism”National Academies Press (US).(1993)
- ^Consolazio CF, Matoush LO, Nelson RA, Harding RS, Canham JEExcretion of sodium, potassium, magnesium and iron in human sweat and the relation of each to balance and requirementsJ Nutr.(1963 Apr)
- ^Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference IntakesDietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride
- ^Yoshimura Y, Fujisaki K, Yamamoto T, Shinohara YPharmacokinetic Studies of Orally Administered Magnesium Oxide in RatsYakugaku Zasshi.(2017 May 1)
- ^Firoz M, Graber MBioavailability of US commercial magnesium preparationsMagnes Res.(2001 Dec)
- ^Gonzales-Arimborgo C, Yupanqui I, Montero E, Alarcón-Yaquetto DE, Zevallos-Concha A, Caballero L, Gasco M, Zhao J, Khan IA, Gonzales GFAcceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii) in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled StudyPharmaceuticals (Basel).(2016 Aug 18)
- ^Zenico T, Cicero AF, Valmorri L, Mercuriali M, Bercovich ESubjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trialAndrologia.(2009 Apr)
- ^Gonzales GF, Córdova A, Vega K, Chung A, Villena A, Góñez C, Castillo SEffect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy menAndrologia.(2002 Dec)
- ^Dording CM, Schettler PJ, Dalton ED, Parkin SR, Walker RS, Fehling KB, Fava M, Mischoulon DA double-blind placebo-controlled trial of maca root as treatment for antidepressant-induced sexual dysfunction in womenEvid Based Complement Alternat Med.(2015)
- ^G. D’Aniello, S. Ronsini, T. Notari, N. Grieco, V. Infante, N. D’Angel, F. Mascia, M. Fiore, G. Fisher and A. D’AnielloD-asparate, a key element for the improvement of sperm qualityAdvances in Sexual Medicine.(2012 Oct)
- ^Topo E, Soricelli A, D'Aniello A, Ronsini S, D'Aniello GThe role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and ratsReprod Biol Endocrinol.(2009 Oct 27)
- ^Melville GW, Siegler JC, Marshall PWThree and six grams supplementation of d-aspartic acid in resistance trained menJ Int Soc Sports Nutr.(2015 Apr 1)
- ^Willoughby DS, Leutholtz BD-aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained menNutr Res.(2013 Oct)
- Sperm Quality - Ahmad MK, Mahdi AA, Shukla KK, Islam N, Rajender S, Madhukar D, Shankhwar SN, Ahmad SWithania somnifera improves semen quality by regulating reproductive hormone levels and oxidative stress in seminal plasma of infertile malesFertil Steril.(2010 Aug)
- Testosterone - Lopresti AL, Smith SJ, Malvi H, Kodgule RAn investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled studyMedicine (Baltimore).(2019 Sep)
- Sperm Quality - Roaiah MF, Elkhayat YI, Saleh SF, Abd El Salam MAProspective Analysis on the Effect of Botanical Medicine (Tribulus terrestris) on Serum Testosterone Level and Semen Parameters in Males with Unexplained InfertilityJ Diet Suppl.(2016 Jun 23)
- Luteinizing Hormone - Roaiah MF, El Khayat YI, GamalEl Din SF, Abd El Salam MAPilot Study on the Effect of Botanical Medicine (Tribulus terrestris) on Serum Testosterone Level and Erectile Function in Aging Males With Partial Androgen Deficiency (PADAM)J Sex Marital Ther.(2016 May 18)
- Testosterone - Saudan C, Baume N, Emery C, Strahm E, Saugy MShort term impact of Tribulus terrestris intake on doping control analysis of endogenous steroidsForensic Sci Int.(2008 Jun 10)
- Erections - GamalEl Din SF, Abdel Salam MA, Mohamed MS, Ahmed AR, Motawaa AT, Saadeldin OA, Elnabarway RRTribulus terrestris versus placebo in the treatment of erectile dysfunction and lower urinary tract symptoms in patients with late-onset hypogonadism: A placebo-controlled studyUrologia.(2018 Sep 25)
- Sperm Quality - Safarinejad MREfficacy of coenzyme Q10 on semen parameters, sperm function and reproductive hormones in infertile menJ Urol.(2009 Jul)
- Luteinizing Hormone - Decio Armanini, Mee Jung Mattarello, Cristina Fiore, Guglielmo Bonanni, Carla Scaroni, Paola Sartorato, Mario PalermoLicorice reduces serum testosterone in healthy womenSteroids.(Oct-Nov 2004)
- Luteinizing Hormone - Mendelson JH, Sholar MB, Mutschler NH, Jaszyna-Gasior M, Goletiani NV, Siegel AJ, Mello NKEffects of intravenous cocaine and cigarette smoking on luteinizing hormone, testosterone, and prolactin in menJ Pharmacol Exp Ther.(2003 Oct)
- Luteinizing Hormone - Gonzales GF, Córdova A, Vega K, Chung A, Villena A, Góñez CEffect of Lepidium meyenii (Maca), a root with aphrodisiac and fertility-enhancing properties, on serum reproductive hormone levels in adult healthy menJ Endocrinol.(2003 Jan)
- Luteinizing Hormone - Brown GA, Vukovich MD, Sharp RL, Reifenrath TA, Parsons KA, King DSEffect of oral DHEA on serum testosterone and adaptations to resistance training in young menJ Appl Physiol.(1999 Dec)
- Testosterone - Morales A, Black A, Emerson L, Barkin J, Kuzmarov I, Day AAndrogens and sexual function: a placebo-controlled, randomized, double-blind study of testosterone vs. dehydroepiandrosterone in men with sexual dysfunction and androgen deficiencyAging Male.(2009 Dec)
- Luteinizing Hormone - E J Cone, R E Johnson, J D Moore, J D RoacheAcute effects of smoking marijuana on hormones, subjective effects and performance in male human subjectsPharmacol Biochem Behav.(1986 Jun)
- Luteinizing Hormone - Chan KQ, Stewart C, Chester N, Hamzah SH, Yusof AThe effect of Eurycoma Longifolia on the regulation of reproductive hormones in young males.Andrologia.(2021-May)
- Testosterone - Sasikala M Chinnappan, Annie George, Pragya Pandey, Govinda Narke, Yogendra Kumar ChoudharyEffect of Eurycoma longifolia standardised aqueous root extract-Physta ® on testosterone levels and quality of life in ageing male subjects: a randomised, double-blind, placebo-controlled multicentre studyFood Nutr Res.(2021 May 19)
- Testosterone - M I B M Tambi, M K Imran, R R HenkelStandardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism?Andrologia.(2012 May)
- Testosterone - Leisegang K, Finelli R, Sikka SC, Panner Selvam MK (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials.Medicina (Kaunas).(2022-Aug-04)
- Strength - Alice Erwig Leitão, Melissa de Carvalho Souza Vieira, Diogo Almeida Gomes, Leonessa Boing, Andreia Pelegrini, Edson Luiz, Adriana Coutinho de Azevedo GuimarãesExercise associated or not to the intake of Eurycoma longifolia improves strength and cardiorespiratory fitness in men with androgen deficiencyComplement Ther Clin Pract.(2021 Feb)
- Testosterone - Gambelunghe C, Rossi R, Sommavilla M, Ferranti C, Rossi R, Ciculi C, Gizzi S, Micheletti A, Rufini SEffects of chrysin on urinary testosterone levels in human malesJ Med Food.(2003 Winter)
- Testosterone - W R Phipps, S E Lukas, J H Mendelson, J Ellingboe, S L Palmieri, I SchiffAcute ethanol administration enhances plasma testosterone levels following gonadotropin stimulation in menPsychoneuroendocrinology.(1987)
- Testosterone - Sarkola T, Fukunaga T, Mäkisalo H, Peter Eriksson CJAcute effect of alcohol on androgens in premenopausal womenAlcohol Alcohol.(2000 Jan)
- Testosterone - Godard MP, Johnson BA, Richmond SRBody composition and hormonal adaptations associated with forskolin consumption in overweight and obese menObes Res.(2005 Aug)
- Testosterone - Strauch G, Perles P, Vergult G, Gabriel M, Gibelin B, Cummings S, Malbecq W, Malice MPComparison of finasteride (Proscar) and Serenoa repens (Permixon) in the inhibition of 5-alpha reductase in healthy male volunteersEur Urol.(1994)
- Testosterone - Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann AEffect of vitamin D supplementation on testosterone levels in menHorm Metab Res.(2011 Mar)
- Testosterone - Nielsen FH, Hunt CD, Mullen LM, Hunt JREffect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal womenFASEB J.(1987 Nov)
- Testosterone - Hayamizu K, Tomi H, Kaneko I, Shen M, Soni MG, Yoshino GEffects of Garcinia cambogia extract on serum sex hormones in overweight subjectsFitoterapia.(2008 Jun)
- Testosterone - Kilic MEffect of fatiguing bicycle exercise on thyroid hormone and testosterone levels in sedentary males supplemented with oral zincNeuro Endocrinol Lett.(2007 Oct)
- Testosterone - Cook C, Beaven CM, Kilduff LP, Drawer SAcute caffeine ingestion increases voluntarily chosen resistance training load following limited sleepInt J Sport Nutr Exerc Metab.(2012 Feb 15)