Drug Database
TE

testosterone (Fortigel / Tostrex / Fortesta)

✓ Approved

Kyowa Kirin Co., Ltd. · AR · Steroids

What is testosterone?

testosterone is a steroids developed by Kyowa Kirin Co., Ltd.. It is approved for therapeutic indications via topical or transdermal.

Drug Profile

Brand NamesFortigel, Tostrex, Fortesta
CompanyKyowa Kirin Co., Ltd.
Drug ClassSteroids, Small Molecule
Molecular TargetAR
RouteTopical, Transdermal
StatusApproved
Sources: ClinicalTrials.gov, Kyowa Kirin Co., Ltd.

Mechanism of Action

Molecular Targets

testosterone acts on 1 molecular target:

ARandrogen receptor (DHTR, AR8)
Want deeper analysis?Noah AI can explain complex mechanisms and compare to similar drugs.

Therapeutic Indications

testosterone is developed for 2 unique indications across 2 therapeutic areas.

Therapeutic AreaConditionPhase
Endocrine disordersHypogonadism✓ Approved
Reproductive system and breast disordersFemale sexual dysfunctionPreclinical

Related Research Articles

PubMedJournal of pediatric endocrinology & metabolism : JPEM2026-08-25

Clinical, hormonal, and genetic spectrum of cryptorchidism: a comprehensive evaluation of patients referred for pediatric endocrinological assessment.

Sütçü Zümrüt Kocabey ZK, Kaplan Emel Hatun Aytaç EHA, Önal Hasan H

Cryptorchidism is the most prevalent pediatric genital anomaly, yet its clinical significance often extends beyond simple anatomical maldescent. While surgical management is well-established, the necessity for holistic endocrine and genetic evaluation remains underexplored. We aimed to characterize the clinical, hormonal, and genetic landscapes of patients referred for pediatric endocrinological assessment following orchiopexy. We retrospectively analyzed 99 boys referred for postoperative evaluation. Clinical findings, basal and dynamic hormonal profiles, and genetic results - including karyotype and targeted DSD gene panels - were evaluated. Preterm birth was recorded in 23.2 % of the cohort, and bilateral involvement was present in 50.5 %. Significant clinical findings included testicular atrophy (34.3 %), scrotal hypoplasia (18.2 %), micropenis (12.1 %), and hypospadias (10.1 %). Hormonal profiling revealed a broad spectrum of FSH (up to 85.7 mIU/mL) and AMH (0.01-71.80 ng/mL) levels. Among patients undergoing hCG stimulation testing, 72.7 % exhibited an insufficient testosterone response. Targeted DSD panel testing in a selected high-risk subgroup yielded a diagnostic rate of 45.4 %, identifying variants in SRD5A2, PTPN11, NR0B1, RAF1, POR, LHX4, and AMHR2. The prevalence of nonisolated cryptorchidism was relatively high, affecting 44.4 % of the cohort. This multisystemic involvement comprised defined syndromic diagnoses (17.2 %) and chronic comorbidities (27.3 %), predominantly endocrine disorders such as congenital hypothyroidism and growth hormone deficiency. The high frequency of bilateral involvement, testicular atrophy, and genetic mutations suggests that many referred cases represent complex syndromic or endocrine conditions rather than isolated maldescent. Comprehensive endocrinological follow-up and targeted genetic testing are essential for early diagnosis and optimizing long-term fertility management.

PMID 42638530
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PubMedTranslational sports medicine2026-08-25

Reducing the Risk of Unintentional Doping From Supplements: A Practical Guide for Athletes and Support Teams.

Mancin Laura L, Close Graeme L GL, Jeukendrup Asker A, Freschi Marco M et al.

Dietary supplements are widely used across all levels of sport. While the 'food first but not food only' approach remains central to sports nutrition, selected supplements may support performance, recovery or health when used appropriately. However, variable regulation, product contamination, mislabelling and inappropriate decision-making may expose athletes to inadvertent antidoping rule violations (ADRVs). This structured narrative review searched PubMed and Scopus for literature published between January 2000 and December 2025. Evidence from primary studies, randomised controlled trials, systematic reviews, meta-analyses, mechanistic studies, contamination analyses, behavioural research, consensus statements and official guidance documents from major sports and antidoping organisations was critically evaluated and synthesised. A PRISMA-style literature identification and evidence-selection diagram is provided as Supporting Table S1; the review was not designed as a systematic review or meta-analysis. Narrative clinical review. Level V for the overall narrative framework, with supplement-specific strength of recommendation reported separately. Evidence supporting supplementation varies substantially across categories. Creatine and caffeine have the most consistent evidence for selected performance outcomes, whereas beta-alanine, dietary nitrate and sodium bicarbonate show context-specific benefits. Iron and vitamin D have clearer clinical indications when deficiency is present, but limited evidence supports routine use in replete athletes. Many recovery- or health-oriented supplements rely on smaller, heterogeneous studies or indirect outcomes. Contamination risk is also heterogeneous and is highest for multi-ingredient products, preworkout supplements, weight-loss products, muscle-building products, 'testosterone boosters', selective androgen receptor modulators (SARMs) and other substances positioned as supplements despite pharmacological or prohibited profiles. Effective risk reduction requires individual nutritional assessment, evidence-based selection, third-party certification, product verification, education of athletes and Athlete Support Personnel, and systematic documentation. Supplement use in athletes should be considered a controlled, individualised and documented intervention rather than routine practice. The proposed framework integrates efficacy, evidence quality, mechanisms of action, contamination pathways, behavioural determinants, strict liability and antidoping risk to support safer supplementation decisions. Protecting athlete health and the integrity of clean sport requires a shift from performance-driven to risk-aware supplementation.Strength-of-Recommendation Taxonomy (SORT): Overall framework: B/C, based on consensus statements, position stands, limited controlled studies and expert-informed synthesis. Supplement-specific ratings are provided in Table 2.

PMID 42639281
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PubMedJournal of the Endocrine Society2026-08-24

Hormonal profiles of men with highly elevated SHBG and primary testicular dysfunction support free hormone hypothesis.

Gagliano-Jucá Thiago T, Puri Ishika I, Ramirez-Rivera Gabriel G, Shekhar Skand S et al.

Free hormone hypothesis (FHH) posits that free testosterone crosses plasma membrane to activate intracellular signaling and is biologically active fraction of circulating testosterone. Widely accepted in other fields, FHH has been debated in andrology. To disentangle the roles of free and total testosterone, we studied men with greatly elevated sex hormone-binding globulin (SHBG) levels and primary hypogonadism, who had marked divergence in total and free testosterone concentrations, in whom elevated gonadotropins provided independent evidence of primary testicular insufficiency. Prospective hormonal evaluation of men with greatly elevated SHBG. Total and free testosterone, LH, FSH, symptom ascertainment. Among 20 men with SHBG>100 nmol/L, 15 met Endocrine Society's criteria for primary hypogonadism: low free testosterone, one or more symptoms/signs, elevated LH and/or FSH. Among 15 men with elevated LH and/or FSH and unequivocally low free testosterone who met the criteria for primary hypogonadism, 4 had total testosterone that exceeded the reference range (>916 ng/dL) and 8 had total testosterone >450 ng/dL, substantially above the lower normal limit. In men with markedly elevated SHBG, in whom total and free testosterone diverged substantially, low free testosterone was associated with elevated gonadotropins, providing independent evidence of primary testicular insufficiency even when total testosterone levels were above the reference range or substantially above the lower normal limit. Although sample size was small, these illustrative "n-of-1" observations in uncommon patients are consistent with the primacy of free testosterone over total testosterone in the hypothalamic-pituitary-testicular feedback loop to regulate LH and FSH, and support the FHH.

PMID 42634762
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PubMedTheScientificWorldJournal2026-08-24

Evaluation of Oxidative Stress and Its Impact on Sperm DNA Fragmentation and Semen Parameters in Infertile Men.

Berrada Kenza K, Touhamia Yasmine Y, Serbouti Asmaa A, Aamiri Abderrahmane A et al.

Oxidative stress, defined as an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays a central role in the pathophysiology of male infertility and has been reported in approximately 30%-80% of infertile men. Excessive ROS production promotes lipid peroxidation, DNA damage, and mitochondrial dysfunction, ultimately compromising sperm quality. The aim of our study was to evaluate oxidative stress biomarkers in seminal plasma, including malondialdehyde (MDA) as a marker of lipid peroxidation and key enzymatic antioxidants superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and to assess their impact on sperm DNA fragmentation, semen parameters, and serum total testosterone levels. Semen samples were collected from a total of 150 participants, including 120 infertile men (30 oligozoospermic, 30 teratozoospermic, 30 asthenozoospermic, and 30 necrozoospermic) and 30 fertile controls. Semen analysis was performed according to WHO 2021 criteria. Sperm DNA fragmentation index (DFI) was assessed using the TUNEL assay. Seminal antioxidant enzyme activities (SOD, CAT, and GPx) and lipid peroxidation levels were measured in seminal plasma using spectrophotometric methods. Serum total testosterone levels were measured using an electrochemiluminescence immunoassay. The results showed that DFI and MDA levels were significantly higher in infertile men compared with controls. Conversely, seminal antioxidant enzyme activities and serum testosterone levels were significantly lower in the infertile groups (p < 0.05). DFI was positively correlated with MDA (r = 0.63, p < 0.001). In contrast, reduced seminal antioxidant enzyme activities and lower testosterone levels were negatively associated with higher DFI and MDA (p < 0.001). Additionally, both DFI and MDA showed negative correlations with semen parameters. Our findings highlight the potential value of oxidative stress biomarkers and sperm DNA fragmentation assessment in the evaluation of male infertility, emphasizing the central role of oxidative stress in sperm dysfunction.

PMID 42635260
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PubMedThe Journal of urology2026-08-24

TESTOSTERONE THERAPY IN MEN ON ACTIVE SURVEILLANCE FOR PROSTATE CANCER IS NOT ASSOCIATED WITH INCREASED RISK OF DISEASE PROGRESSION.

Flores Jose M JM, Kim Daniel D, Yu Rebecca R, Vertosick Emily A EA et al.

Testosterone therapy (TTH) in men with prostate cancer (PC) remains controversial, with limited data on cancer specific outcomes for patients on TTH available, particularly for those on Active Surveillance (AS). This study aimed to assess the safety of TTh in men on AS for PC. The records of patients with Grade Group (GG) 1 and 2 PC on AS were reviewed, including a subset who were concurrently treated with TTH. Institutional protocols for AS consisted of lab work and exam every 6 months, MRI every 18 months, and biopsy every 36 months. Men on TTH had total testosterone and PSA labs drawn within 2-4 weeks of TTH initiation and every 6 months when stable on dosing. The primary outcome was time to progression, defined as a rise in GG on biopsy. A secondary outcome used an alternative definition of progression to definitive treatment. The study included 3,324 AS patients, with 79 on TTH. 1,256 (38%) patients had progression on biopsy. On multivariable analysis, TTH did not significantly impact the risk of disease progression (HR 0.99; 95% CI: 0.67,1.48; p>0.9), with adjusted survival curves failing to demonstrate clinically meaningful differences in event rates. Similarly, TTH did not impact progression to definitive treatment (HR 0.94; 95% CI: 0.64, 1.38; p=0.8). While TTh can be used in patients on active surveillance, careful monitoring is indicated and further research necessary to confirm oncologic safety with larger and more mature cohorts.

PMID 42636428
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PubMedSexual medicine reviews2026-08-24

A critical analysis of the quality of testosterone therapy randomized controlled trials.

Furtado Thiago P TP, Novaes Luis F LF, Flores Jose M JM, Mulhall John P JP

In recent years, the utilization of testosterone (T)s testing and prescriptions has experienced a significant surge. As a result, the market for testosterone therapy (TTh) has increased dramatically with the surge of T products undergoing trials. Our aim was to undertake a critical analysis of randomized controlled trials (RCTs) that focused on TTh, specifically with an emphasis on the quality of the trials and their delineation of adverse events (AE). A literature review of PubMed was conducted to identify RCTs using TTh, excluding non-English, animal, or female-based studies. Trials were assessed for sample size, duration, pre-, and post-treatment T levels, adverse event definitions. We also assessed the reported rates of polycythemia (PCT), gynecomastia (GYN), major adverse cardiovascular events (MACE), and obstructive sleep apnea (OSA). Thirty RCTs met the inclusion criteria, with a median study sample size of 76 and median follow-up of 8 months. The present analysis reveals that TTh trials are highly heterogeneous in both reporting of definitions and rates of AEs, such as PCT, GYN, and MACE. Among the included trials, 83% measured hematocrit (HCT) levels, but only 23% reported baseline values, with a median baseline HCT of 43% and an on-treatment median of 45%. GYN was reported in 17% of the RCTs, though none detailed the grade of GYN. MACE were reported in only 20% of the trials, with varying definitions. OSA was mentioned as an AE in 33% of trials, but only three reported incidence rates. This analysis highlights the suboptimal reporting of AE outcomes in TTh RCTs. These findings underscore the need for a greater level of standardization in such trials.

PMID 42636349
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