Testosterone is an androgen hormone involved in male sexual development and studied in muscle, bone, body-composition, and libido-related outcomes 1 2 3 9 12. Human randomized trials have studied testosterone in hypogonadism, body composition, fracture outcomes, gender-affirming care, and selected prostate-cancer contexts. FDA-approved testosterone products exist by prescription, but not every research context discussed here is an FDA-approved indication. This guide summarizes evidence, safety, studied dosing information, and clinician-supervised access.
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See if you qualify →What it is
Testosterone is a steroid hormone in the androgen class. In plain English, androgens are hormones that help regulate male sexual development, reproductive function, muscle, bone, and other body systems; clinical trials in the retrieved evidence set have studied testosterone in hypogonadism, body composition, gender-affirming care, fracture outcomes, sexual desire, severe energy deficit, and prostate-cancer research contexts 1 2 3 6 8 9 10.
Common names include testosterone, testosterone cypionate, testosterone enanthate, testosterone undecanoate, and transdermal testosterone. The retrieved trial set specifically includes testosterone enanthate, testosterone undecanoate, oral testosterone undecanoate, and transdermal testosterone as studied forms 6 7 9 10.
Chia does not offer testosterone. If you are trying to understand possible low-testosterone symptoms, our education pages on TRT, symptoms of low testosterone in men, and testosterone deficiency can help you prepare for a clinician visit.
Evidence grade: A
This page assigns testosterone an evidence grade of A because the retrieved PubMed evidence set includes multiple human randomized controlled trials of testosterone in different populations and outcomes 1 2 3 6 8 9 10.
Evidence grade rubric
A — two or more human randomised controlled trials. B — one human randomised trial, or two or more human clinical trials. C — human research exists, none of it randomised. D — animal or in-vitro research only; no human studies indexed. E — no trial evidence indexed in PubMed. The grade describes the quantity and design of published evidence, not whether the substance works, and not whether it is safe.
Mechanism of action
Testosterone is generally understood as an androgen hormone that acts through androgen-receptor signaling. The retrieved evidence set supports that testosterone has been tested in human trials measuring outcomes tied to androgen biology, including muscle size and strength, body composition, hypogonadism outcomes, sexual desire, and prostate-cancer contexts, but these records do not by themselves provide a full receptor-level mechanism paper 1 2 8 9.
In body-composition research, testosterone dose-response and supraphysiologic-dose trials in men studied muscle size, strength, and related physiologic outcomes 1 2. A separate randomized trial in aging men reported effects on subcutaneous fat and adiponectin, a metabolic hormone made by fat tissue 12.
In severe energy deficit research, randomized trials studied testosterone enanthate and measured metabolomics and gut microbiota responses, showing that investigators have examined testosterone in metabolic-stress settings as well as classic hormone-deficiency settings 10 11.
For a real clinical decision, blood levels and symptoms both matter because trials are done in defined populations, such as healthy young men, aging men, men with hypogonadism, trans males, postmenopausal women, and prostate-cancer groups 1 3 6 8 9 12. A trial result from one group should not be treated as a personal answer for another group.
Evidence
Testosterone has evidence grade A in this retrieved set because multiple human randomized controlled trials are indexed for testosterone 1 2 3 6 8 9 10 11.
A — two or more human randomised controlled trials. B — one human randomised trial, or two or more human clinical trials. C — human research exists, none of it randomised. D — animal or in-vitro research only; no human studies indexed. E — no trial evidence indexed in PubMed. The grade describes the quantity and design of published evidence, not whether the substance works, and not whether it is safe.
Body composition and strength
Human randomized trials have studied testosterone dose-response relationships in healthy young men and the effects of supraphysiologic doses of testosterone on muscle size and strength in normal men 1 2. These studies are useful for understanding biology, but they do not mean that a person should use testosterone for body-composition goals without a clinician-led evaluation.
Aging-men research in the retrieved set also includes a randomized trial reporting that testosterone therapy decreased subcutaneous fat and adiponectin 12. That same finding should be read with safety context, because changes in fat or biomarkers do not prove overall health benefit for every person.
Hypogonadism and bone outcomes
In men with hypogonadism, a randomized trial studied testosterone treatment and fractures 3. This matters because bone outcomes are patient-important outcomes, not just lab values, but the details of fracture risk and benefit depend on the population studied and the person’s medical history.
Gender-affirming hormone therapy
A randomized controlled trial compared testosterone enanthate and testosterone undecanoate as gender-affirming hormonal therapy in trans males 6. This supports that testosterone has been studied in gender-affirming care, while the right treatment plan still depends on an individual’s goals, labs, anatomy, fertility plans, and risk factors.
Sexual desire and reproductive-hormone research
A placebo-controlled randomized clinical trial studied transdermal testosterone for postmenopausal sexual desire 9. Another randomized trial studied the relationship between ejaculation and serum testosterone level in men, showing that not all testosterone studies are treatment trials 13.
Prostate-cancer contexts
The retrieved evidence includes a randomized clinical trial of testosterone treatment in prostate-cancer survivors with hypogonadism and an open-label phase II trial of bipolar androgen therapy in men with metastatic castration-resistant prostate cancer 8 5. These are specialized research contexts and should not be generalized to people with a prostate-cancer history without specialist care.
The retrieved evidence also includes a phase 3 prostate-cancer study comparing testosterone recovery after relugolix versus leuprolide in men with advanced prostate cancer 4. That kind of study is about testosterone recovery in a cancer-treatment setting, not routine hormone self-treatment.
Evidence limits
The main limit is not a lack of human trials; it is that the trials ask different questions in different groups. Healthy young men, aging men, men with hypogonadism, trans males, postmenopausal women, and prostate-cancer populations are not interchangeable 1 3 6 8 9 12.
What studies exist
| Year | Design | Study | Journal | Record |
|---|---|---|---|---|
| 2001 | Randomised controlled trial | Testosterone dose-response relationships in healthy young men | American journal of physiology. Endocrinology and metabolism | PMID 11701431 |
| 1996 | Randomised controlled trial | The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men | The New England journal of medicine | PMID 8637535 |
| 2024 | Randomised controlled trial | Testosterone Treatment and Fractures in Men with Hypogonadism | The New England journal of medicine | PMID 38231621 |
| 2024 | Randomised controlled trial | Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study | European urology oncology | PMID 38143206 |
| 2021 | Clinical trial | A Multicohort Open-label Phase II Trial of Bipolar Androgen Therapy in Men with Metastatic Castration-resistant Prostate Cancer (RESTORE): A Comparison of Post-abiraterone Versus P | European urology | PMID 32624280 |
| 2025 | Randomised controlled trial | A Randomized Controlled Trial Comparing Testosterone Enanthate and Testosterone Undecanoate as a Gender Affirming Hormonal Therapy in Trans Males | Clinical endocrinology | PMID 40012162 |
| 2025 | Randomised controlled trial | Safety, efficacy, and pharmacokinetics of oral testosterone undecanoate in males with hypogonadism | Andrology | PMID 39252657 |
| 2026 | Randomised controlled trial | Testosterone administration partially modulates gut microbiota responses to severe energy deficit | American journal of physiology. Endocrinology and metabolism | PMID 41874457 |
| 2026 | Randomised controlled trial | Testosterone Treatment in Prostate Cancer Survivors With Hypogonadism: A Randomized Clinical Trial | JAMA internal medicine | PMID 42113507 |
| 2026 | Randomised controlled trial | Effect of transdermal testosterone on postmenopausal sexual desire: placebo-controlled randomized clinical trial | European journal of obstetrics, gynecology, and reproductive biology | PMID 42302467 |
| 2022 | Randomised controlled trial | Metabolomics of testosterone enanthate administration during severe-energy deficit | Metabolomics : Official journal of the Metabolomic Society | PMID 36450940 |
| 2025 | Randomised controlled trial | Testosterone Effects on Short-term Physical, Hormonal, and Neurodevelopmental Outcomes (TESTO) in Infants With 47,XXY | The Journal of clinical endocrinology and metabolism | PMID 40177735 |
| Registration | Phase | Status | Enrolment | Title |
|---|---|---|---|---|
| NCT02248467 | N/A | COMPLETED | 100 | Study of the Effect of Testosterone Treatment on Metabolic Parameters and Urinary Symptoms in Bariatric Patients |
| NCT04104893 | PHASE2 | ACTIVE_NOT_RECRUITING | 40 | A Study of CHeckpoint Inhibitors in Men With prOgressive Metastatic Castrate Resistant Prostate Cancer Characterized by a Mismatch Repair Deficiency or Biallelic CDK12 Inactivation |
| NCT04895306 | PHASE2 | COMPLETED | 36 | Testosterone Replacement to Alleviate Pain in Postmenopausal Women (TRAPP Trial) |
| NCT03568604 | PHASE4 | COMPLETED | 18 | Changes to Vulva, Vestibule, Urethral Meatus and Vagina 20 Weeks Post Daily Prasterone in Women With Dyspareunia |
| NCT01107067 | PHASE4 | COMPLETED | 32 | Testosterone Replacement Therapy Decreases Plasma Paraoxonase 1 Enzyme Activity In Male Patients With Hypogonadism |
| NCT07085715 | N/A | NOT_YET_RECRUITING | 500 | Pan-Viral Screening and Linkage to Care Among GBMSM and Trans Women in Spain |
| NCT07649421 | PHASE2 | NOT_YET_RECRUITING | 254 | PSMA PET/CT-Guided SBRT Plus Darolutamide in mHSPC |
| NCT00675714 | PHASE2, PHASE3 | TERMINATED | 1126 | Assessment of the Treatment of Severely Burned With Anabolic Agents on Clinical Outcomes, Recovery and Rehabilitation |
This table is retrieved from PubMed and ClinicalTrials.gov rather than assembled by hand, so it shows what is indexed — including the absences. Last retrieved 2026-09-07.
Reported dosing ranges
Testosterone dosing is not something to copy from a study table. The retrieved records identify studied forms and populations, but the source excerpts available here do not provide extractable numeric dosing ranges for each study; for that reason, this section reports what was studied, not personal dose instructions.
| Form or context | What the retrieved source studied | Dose information available in this evidence set | Source |
|---|---|---|---|
| Testosterone dose-response study | Dose-response relationships in healthy young men | Numeric dosing range not available in the retrieved record excerpt | Bhasin et al., 2001 1 |
| Supraphysiologic testosterone | Effects on muscle size and strength in normal men | Numeric dosing range not available in the retrieved record excerpt | Bhasin et al., 1996 2 |
| Testosterone treatment in hypogonadism | Fracture outcomes in men with hypogonadism | Numeric dosing range not available in the retrieved record excerpt | Snyder et al., 2024 3 |
| Testosterone enanthate and testosterone undecanoate | Gender-affirming hormonal therapy in trans males | Numeric dosing range not available in the retrieved record excerpt | Sinju et al., 2025 6 |
| Oral testosterone undecanoate | Safety, efficacy, and pharmacokinetics in males with hypogonadism | Numeric dosing range not available in the retrieved record excerpt | Miner et al., 2025 7 |
| Transdermal testosterone | Postmenopausal sexual desire in a placebo-controlled randomized clinical trial | Numeric dosing range not available in the retrieved record excerpt | Ceccatto Andrade et al., 2026 9 |
| Testosterone enanthate during severe energy deficit | Metabolomics outcomes during severe energy deficit | Numeric dosing range not available in the retrieved record excerpt | Stein et al., 2022 10 |
Monitoring and adjustment belong with a clinician because trials measure specific outcomes under study protocols, while patient care must account for symptoms, labs, medical history, fertility goals, and risks. The safety trials and prostate-cancer-context trials in this evidence set show why medical context matters 3 4 5 8.
Legal status
| Date | Action | What it means | Source | Evidence |
|---|---|---|---|---|
| 2026-09-02 | FDA-approved labelling containing Testosterone is on file with DailyMed (verified 2026-09-02) | An FDA-approved product with this active ingredient is available by prescription. | DailyMed (NLM) | FDA / Federal Register |
This section is generated from a dated log of federal actions rather than written by hand, and it is re-checked daily against the Federal Register and FDA sources. Last checked 2026-09-07. See the full legal-status tracker for every compound we follow.
Safety
Testosterone safety depends on the person, the reason it is being considered, the form, and the monitoring plan. The retrieved evidence includes randomized and clinical trials in hypogonadism, prostate-cancer survivors, advanced prostate cancer, gender-affirming care, postmenopausal sexual desire, and severe energy deficit, which means safety cannot be reduced to one simple rule 3 4 5 6 8 9 10 11.
Bone safety deserves special care because a randomized trial specifically studied testosterone treatment and fractures in men with hypogonadism 3. A treatment that changes hormone levels can affect more than symptoms, so fracture outcomes, labs, and medical history all matter.
Prostate-cancer history also changes the safety conversation. The retrieved evidence includes testosterone treatment in prostate-cancer survivors with hypogonadism, bipolar androgen therapy in metastatic castration-resistant prostate cancer, and testosterone recovery after prostate-cancer hormone therapies 4 5 8.
Supply quality is a separate safety issue. Products sold as “research use only” are not made as patient medications, and a buyer may not have reliable assurance about sterility, identity, or impurities; that is why a clinician-reviewed process and a licensed pharmacy matter.
Interactions
Testosterone decisions can interact with a person’s conditions, goals, and current therapies. The retrieved evidence set includes prostate-cancer contexts, hypogonadism, gender-affirming care, postmenopausal sexual desire, bariatric-metabolic research, and severe energy deficit, which are different clinical situations rather than one shared use case 3 4 5 6 8 9 10 11.
| Situation | Why it matters | Evidence source |
|---|---|---|
| Prostate cancer history or active prostate-cancer treatment | Trials in the retrieved set studied testosterone treatment, testosterone recovery, or androgen-based strategies in prostate-cancer contexts; these are specialist settings. | Tutrone et al., 2024; Markowski et al., 2021; Bhasin et al., 2026 4 5 8 |
| Hypogonadism | Trials studied testosterone in men with hypogonadism, including fracture outcomes and oral testosterone undecanoate research. | Snyder et al., 2024; Miner et al., 2025 3 7 |
| Gender-affirming hormone therapy | A randomized trial compared testosterone enanthate and testosterone undecanoate in trans males. | Sinju et al., 2025 6 |
| Postmenopausal sexual desire | A placebo-controlled randomized trial studied transdermal testosterone in this context. | Ceccatto Andrade et al., 2026 9 |
| Severe energy deficit or metabolic stress | Randomized trials studied testosterone enanthate with metabolomics and gut microbiota outcomes during severe energy deficit. | Stein et al., 2022; Mohr et al., 2026 10 11 |
This evidence set does not provide a complete drug-interaction database for testosterone. That absence is not proof of no interactions; it means medication lists, supplements, diagnoses, and lab results need clinician review.
How to obtain it legally
The right process starts with symptoms, health history, and appropriate lab testing. Because testosterone has been studied in very different populations, including hypogonadism, gender-affirming care, postmenopausal sexual desire, severe energy deficit, and prostate-cancer contexts, the first question is not “which product,” but “what problem are we evaluating?” 3 6 8 9 10.
Chia does not offer testosterone. We do offer education on related hormone-health questions, including what TRT is, how to increase testosterone, and what to know about testosterone boosters.
A clinician-reviewed process is different from buying from a gray-market or “research chemical” vendor. In clinical care, a clinician reviews history, symptoms, labs, medications, and risks; if treatment is considered, follow-up monitoring is part of the plan.
If your real question is whether symptoms could be hormonal, start with testing and a medical visit rather than self-treatment. Our guide to peptides vs steroids may also help if you are comparing testosterone, peptides, and other performance or longevity compounds.
| Option people compare | What it is | Main caution |
|---|---|---|
| Clinician-evaluated testosterone care | A medical process based on symptoms, labs, history, and monitoring. | Trial data do not replace individual evaluation. |
| Over-the-counter testosterone boosters | Supplements marketed for testosterone support. | Marketing claims may not match a diagnosed hormone problem; consider reading Chia’s testosterone booster guide. |
| Peptides | Short chains of amino acids studied or used for many different goals. | Peptides and testosterone are not the same class; see peptides vs steroids. |
| Lifestyle changes | Sleep, nutrition, resistance training, weight management, and alcohol moderation are common general-health steps. | Symptoms still deserve testing when they are persistent or severe. |
Grade A means the retrieved PubMed evidence set includes two or more human randomized controlled trials. It describes the quantity and design of evidence, not whether testosterone is right or safe for a specific person.
Testosterone is the hormone. Testosterone cypionate, testosterone enanthate, and testosterone undecanoate are forms or esters used in different treatment and research contexts.
Normal ranges vary by lab, age, timing of the blood draw, and clinical context. A clinician should interpret the number along with symptoms and medical history.
Lifestyle steps such as sleep, resistance training, enough calories and protein, weight management, and limiting heavy alcohol use are general-health considerations, but persistent symptoms should prompt testing instead of guessing; this retrieved testosterone trial set includes severe-energy-deficit research rather than a complete lifestyle-treatment guide 10 11.
No single food reliably fixes a hormone problem. A balanced diet that supports healthy weight, enough protein, micronutrients, and stable energy intake is a better goal.
No. Chia does not offer testosterone. Our testosterone content is education-only, and we encourage clinician evaluation and appropriate lab testing for hormone concerns.
References
- 1.PMID 11701431 [randomised controlled trial] Bhasin S, Woodhouse L, Casaburi R, et al. Testosterone dose-response relationships in healthy young men. American journal of physiology. Endocrinology and metabolism. 2001.
- 2.PMID 8637535 [randomised controlled trial] Bhasin S, Storer TW, Berman N, et al. The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. The New England journal of medicine. 1996.
- 3.PMID 38231621 [randomised controlled trial] Snyder PJ, Bauer DC, Ellenberg SS, et al. Testosterone Treatment and Fractures in Men with Hypogonadism. The New England journal of medicine. 2024.
- 4.PMID 38143206 [randomised controlled trial] Tutrone R, Saad F, George DJ, et al. Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study. European urology oncology. 2024.
- 5.PMID 32624280 [clinical trial] Markowski MC, Wang H, Sullivan R, et al. A Multicohort Open-label Phase II Trial of Bipolar Androgen Therapy in Men with Metastatic Castration-resistant Prostate Cancer (RESTORE): A Comparison of Post-abiraterone Versus Post-enzalutamide Cohorts. European urology. 2021.
- 6.PMID 40012162 [randomised controlled trial] Sinju S, Sridhar S, Sreenivasan P, et al. A Randomized Controlled Trial Comparing Testosterone Enanthate and Testosterone Undecanoate as a Gender Affirming Hormonal Therapy in Trans Males. Clinical endocrinology. 2025.
- 7.PMID 39252657 [randomised controlled trial] Miner M, Wang C, Kaminetsky J, et al. Safety, efficacy, and pharmacokinetics of oral testosterone undecanoate in males with hypogonadism. Andrology. 2025.
- 8.PMID 42113507 [randomised controlled trial] Bhasin S, Burnett AL, Gagliano-Jucá T, et al. Testosterone Treatment in Prostate Cancer Survivors With Hypogonadism: A Randomized Clinical Trial. JAMA internal medicine. 2026.
- 9.PMID 42302467 [randomised controlled trial] Ceccatto Andrade VP, Araujo Júnior E, Callado GY, et al. Effect of transdermal testosterone on postmenopausal sexual desire: placebo-controlled randomized clinical trial. European journal of obstetrics, gynecology, and reproductive biology. 2026.
- 10.PMID 36450940 [randomised controlled trial] Stein JA, Karl JP, Berryman CE, et al. Metabolomics of testosterone enanthate administration during severe-energy deficit. Metabolomics : Official journal of the Metabolomic Society. 2022.
- 11.PMID 41874457 [randomised controlled trial] Mohr AE, Berryman CE, Harris MN, et al. Testosterone administration partially modulates gut microbiota responses to severe energy deficit. American journal of physiology. Endocrinology and metabolism. 2026.
- 12.PMID 22190001 [randomised controlled trial] Frederiksen L, Højlund K, Hougaard DM, et al. Testosterone therapy decreases subcutaneous fat and adiponectin in aging men. European journal of endocrinology. 2012.
- 13.PMID 12659241 [randomised controlled trial] Jiang M, Xin J, Zou Q, et al. A research on the relationship between ejaculation and serum testosterone level in men. Journal of Zhejiang University. Science. 2003.
About this article
Chia Health Editorial Team — Evidence-reviewed health education
This article is for educational purposes only and is not a substitute for individualized medical advice. Talk to a licensed clinician before starting, stopping, or changing any prescription.
AI tools may assist with research and drafting. Chia's editorial team reviews source use, clarity, treatment information, and safety framing before publication. A clinician is named only after explicit sign-off. Read our editorial standards.
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