Testosterone
Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Testosterone replacement therapy (TRT) is indicated for male hypogonadism when low testosterone levels are confirmed by laboratory testing with consistent signs and symptoms. The Testosterone Trials (TTrials) demonstrated improvements in sexual function, mood, bone density, and anemia in men over 65 with low testosterone. Available formulations include topical gels, intramuscular injections, transdermal patches, and nasal gel.
Exploratory record, not a reviewed medical publication.
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This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Testosterone replacement therapy (TRT) is indicated for male hypogonadism when low testosterone levels are confirmed by laboratory testing with consistent signs and symptoms. NutriStack rates the supporting evidence as strong. Common adult dosing is Topical gel: 50–100 mg daily; IM injection (cypionate/enanthate): 100–200 mg every 1–2 weeks; Aveed: 750 mg IM every 10 weeks (as prescribed by your physician), though a prescriber sets the actual dose. This profile indexes 10 sources.
- Polycythemia (elevated hematocrit/hemoglobin)
- Acne and oily skin
- Gynecomastia
- Breast cancer in men
- Known or suspected prostate cancer
The bottom line
Evidence rating strong. Most-documented uses: restores libido and sexual function in hypogonadal men, improves bone mineral density, increases lean muscle mass and strength. 10 sources indexed (2024–2025), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Exogenous testosterone replaces or supplements endogenous androgen production. Testosterone binds to androgen receptors in target tissues, translocates to the nucleus, and regulates gene transcription for proteins involved in male sexual development, muscle mass and strength, bone mineral density, erythropoiesis, fat distribution, and mood. Testosterone is also converted to dihydrotestosterone (DHT) by 5-alpha-reductase and to estradiol by aromatase, mediating additional effects.1,2
Dosing & protocol.
Topical gel: Apply to clean, dry skin (shoulders, upper arms, or abdomen depending on product). Allow to dry before dressing. Wash hands thoroughly. Avoid skin-to-skin contact with women and children at application site.
Full safety detail.
Side effects
- Polycythemia (elevated hematocrit/hemoglobin)
- Acne and oily skin
- Gynecomastia
- Testicular atrophy and reduced sperm production
- Sleep apnea worsening
- Edema
- Mood changes (irritability, aggression)
- Skin irritation at application site (topical)
Contraindications
- Breast cancer in men
- Known or suspected prostate cancer
- Pregnancy or women who may become pregnant (teratogenic)9
- Severe untreated sleep apnea
- Uncontrolled heart failure
- Polycythemia (hematocrit >54%)
- Desire for fertility (suppresses spermatogenesis)
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
5- 1Impact of Testosterone on Male Health: A Systematic ReviewPMIDRojas-Zambrano JG, Rojas-Zambrano A, Rojas-Zambrano AF · Cureus · 2025
Rojas-Zambrano JG, Rojas-Zambrano A, Rojas-Zambrano AF. Impact of Testosterone on Male Health: A Systematic Review. Cureus. 2025
- 2Cardiovascular safety of testosterone replacement therapy in men: an updated systematic review and meta-analysisPMIDCorona G, Rastrelli G, Sparano C et al. · Expert opinion on drug safety · 2024
Corona G, Rastrelli G, Sparano C et al.. Cardiovascular safety of testosterone replacement therapy in men: an updated systematic review and meta-analysis. Expert opinion on drug safety. 2024
- 3Do "testosterone boosters" really increase serum total testosterone? A systematic reviewPMIDMorgado A, Tsampoukas G, Sokolakis I et al. · International journal of impotence research · 2024
Morgado A, Tsampoukas G, Sokolakis I et al.. Do "testosterone boosters" really increase serum total testosterone? A systematic review. International journal of impotence research. 2024
- 4Testosterone replacement therapy and vascular thromboembolic events: a systematic review and meta-analysisPMIDCannarella R, Gusmano C, Leanza C et al. · Asian journal of andrology · 2024
Cannarella R, Gusmano C, Leanza C et al.. Testosterone replacement therapy and vascular thromboembolic events: a systematic review and meta-analysis. Asian journal of andrology. 2024
- 5Do statins decrease testosterone in men? Systematic review and meta-analysisPMIDGlina FPA, Lopes L, E Silva RS et al. · International braz j urol : official journal of the Brazilian Society of Urology · 2024
Glina FPA, Lopes L, E Silva RS et al.. Do statins decrease testosterone in men? Systematic review and meta-analysis. International braz j urol : official journal of the Brazilian Society of Urology. 2024
Reference material
5- 6Snyder PJ et al. Effects of testosterone treatment in older men (Testosterone Trials). N Engl J Med. 2016;374(7):611-624.Source linkedPMID
- 7Bhasin S et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744.Source linkedPMID
- 8Lincoff AM et al. Cardiovascular safety of testosterone-replacement therapy (TRAVERSE). N Engl J Med. 2023;389(2):107-117.Source linkedPMID
- 9Islam RM, Bell RJ, Green S et al.. Safety and efficacy of testosterone for women: a systematic review and meta-analysis of randomised controlled trial data. The lancet. Diabetes & endocrinology. 2019Source linkedPMID
- 10Te L, Liu J, Ma J et al.. Correlation between serum zinc and testosterone: A systematic review. Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2023Source linkedPMID
Common questions.
Quick answers about Testosterone, drawn from the data on this page.
What is Testosterone?
Testosterone replacement therapy (TRT) is indicated for male hypogonadism when low testosterone levels are confirmed by laboratory testing with consistent signs and symptoms. The Testosterone Trials (TTrials) demonstrated improvements in sexual function, mood, bone density, and anemia in men over 65 with low testosterone. Available formulations include topical gels, intramuscular injections, transdermal patches, and nasal gel.
What is Testosterone used for?
Commonly cited benefits of Testosterone include: Restores libido and sexual function in hypogonadal men; Improves bone mineral density; Increases lean muscle mass and strength; Improves mood, energy, and sense of well-being; Corrects testosterone-deficiency anemia. NutriStack rates the overall evidence as strong.
What is a typical dose of Testosterone?
A typical adult dose of Testosterone is Topical gel: 50–100 mg daily; IM injection (cypionate/enanthate): 100–200 mg every 1–2 weeks; Aveed: 750 mg IM every 10 weeks (as prescribed by your physician). The commonly recommended form is Topical gel (most common), intramuscular injection, or transdermal patch. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Testosterone?
Reported side effects include polycythemia (elevated hematocrit/hemoglobin), acne and oily skin, gynecomastia, testicular atrophy and reduced sperm production, sleep apnea worsening, edema. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Testosterone?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Testosterone in NutriStack.
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