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

PubMedReproduction & fertility2026-10-20

Testosterone as part of hormone replacement therapy in menopausal women - what do we know so far? A Narrative Review.

Mishra Ishita I, Robinson Lynne L

Testosterone, widely known as the male hormone, is also produced naturally in women and plays an important role throughout their lifespan. There has been a growing use of testosterone for a range of symptoms in menopausal women, including low sexual desire, low mood, fatigue, poor memory, and heart and bone health. This review brings together the current evidence and guidelines on testosterone as part of hormone replacement therapy (HRT) in menopausal women, including its impact on reproductive and non-reproductive tissues; when it is indicated to be prescribed and in what forms; safety and gaps in existing evidence. We found that there is high-quality evidence to support the use of testosterone for low sexual desire where conventional HRT has not helped. Transdermal preparations are recommended with no serious side effects at testosterone levels normally found in women. There is insufficient evidence to support its use for brain, heart and bone health. This represents an area of focus for future research.

PMID 42900600
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PubMedMolecular human reproduction2026-10-20

The ovaries of transgender men indicate effects of testosterone treatment on the ovarian stroma without changes in non-growing follicle density.

Bailie Emily E, Grosbois Johanne J, Hawthorn Robert R, Jack Stuart S et al.

The ovarian stroma surrounds ovarian follicles and provides a supportive microenvironment during follicle quiescence and subsequent growth. In this study, we investigated the effect of testosterone exposure on human ovarian stromal composition, specifically collagen and elastin content and stromal cell density (SCD), and its relationship with non-growing follicle density (NGFD). Whole ovaries were obtained from transgender men receiving long-term testosterone therapy (mean age 27.6 ± 1.7 years, n = 8) at oophorectomy and compared with ovarian cortical biopsies from age-matched healthy women obtained at caesarean section (mean age 31.8 ± 1.5 years, n = 8). Testosterone-exposed ovarian tissue demonstrated a more fibrotic stromal composition, characterised by increased collagen and reduced elastin, resulting in a higher collagen-elastin ratio indicative of increased intrinsic tissue rigidity. SCD was significantly higher in testosterone-exposed tissue, consistent with stromal cell hyperplasia, whereas NGFD was comparable to controls. These findings indicate that elevated circulating testosterone alters ovarian stromal composition and cellularity without reducing the non-growing follicle pool. Although interpretation is limited by the use of pregnancy-derived control tissue, these findings provide insight into the effects of testosterone on the ovarian microenvironment and warrant further investigation of their functional significance for transgender men considering pregnancy or fertility preservation.

PMID 42900507
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PubMedAutonomic neuroscience : basic & clinical2026-10-20

Exogenous testosterone use in cisgender heterosexual females with postural orthostatic tachycardia syndrome: A dual case report.

Boris Jeffrey R JR

Exogenous testosterone has been previously reported to have given clinical improvement in symptoms of postural orthostatic tachycardia syndrome (POTS) in reported cases of transgender patients during their transition from female to male. Herein is presented two case reports of cisgender heterosexual female patients with POTS who have used testosterone for the management of concurrent gynecologic problems, but who also found that symptoms of both POTS and joint hypermobility improved after its administration.

PMID 42900975
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PubMedAddiction & health2026-10-20

A Comparison of the Long-Term Effects of Opium Tincture and Methadone Syrup on Testicular and Prostate Histology in Male Rats.

Shabani Asma A, Sanjari Ali A, Namaei Mohammad Hasan MH, Hassanzadeh-Taheri Mohammad Mehdi MM et al.

A common way to treat opioid dependence is the consumption of opioids, particularly opium and methadone. However, there is little information about its long-term effects on male reproductive health. In this study, rats› male reproductive system›s hormonal and histological parameters were examined in relation to the long-term oral effects of methadone syrup and opium tincture. 42 male adult Wistar rats were randomly divided into six equal groups and administered orally with methadone (dose escalation to 50 mg/kg) or opium tincture (dose escalation to 200 mg/kg) for 4 or 8 weeks. At the conclusion of treatment, serum testosterone, the relative weights of the prostate and testes, Johnson's score, and histomorphometric indices such as seminiferous tubule area, germinal epithelium area, and prostatic epithelial height were measured. Chronic opium tincture treatment significantly decreased serum testosterone, relative testicular and prostatic weights, and testicular histological indicators (P<0.05). Methadone also damaged certain histology measurements but had a lower impact on testosterone. Prostatic epithelial height increased significantly in the 8-week methadone group, whereas all opium groups exhibited notable decreases (P<0.05). Prolonged oral opium tincture causes more detrimental effects on male reproductive function than methadone, whereas extended methadone exposure may lead to prostate-specific structural changes. These findings highlight the need for careful selection and administration of opioid substitution treatments to diminish the risks of reproduction in dependent individuals.

PMID 42898480
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PubMedFrontiers in endocrinology2026-10-20

INSL3: an informative testis biomarker for assessing the HPG axis in men.

Anand-Ivell Ravinder R, Yang Xinyuan X, Tulumcu Bilal B, Ivell Richard R

The male hypothalamo-pituitary-gonadal (HPG) axis is an integrated endocrine system linking hypothalamic GnRH secretion, pituitary gonadotropins (LH and FSH), Leydig cell steroidogenesis, Sertoli cell function, and spermatogenesis. While conventional parameters such as testosterone or LH may be subject to high biological variance due to their pulsatile mode of secretion and multiple stress-related or environmental influences, the Leydig-cell-secreted peptide insulin-like peptide 3 (INSL3) offers a robust and constitutive alternative reflecting Leydig cell number, differentiation status, and long-term functional capacity. This narrative review considers INSL3 across the male life course in relation to other components of the HPG axis, including in fetal development, minipuberty, pubertal development, and male aging. It shows how measuring INSL3 offers important granularity in understanding issues such as the effects of environmental endocrine disruption, childhood, and lifestyle influences on pubertal development as well as on adult Leydig cell capacity, hypogonadism, and age-related morbidity. The presented evidence suggests that INSL3 will prove to be a useful biomarker for the HPG axis in adult life, though the reference range in healthy adults is quite large for yet unknown reasons; associations with BMI as well as early childhood and adolescent influences are described. While INSL3 reflects the GnRH-LH-testosterone arm of the HPG axis and is normally not directly linked to the spermatogenic compartment and male fertility, some studies do suggest a supportive relationship which merits further research. Similarly, other functions of INSL3 in men also remain underexplored.

PMID 42899007
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PubMedReproductive sciences (Thousand Oaks, Calif.)2026-10-20

Roles and Biological Effects of Polysaccharides in Polycystic Ovary Syndrome: A Narrative Review.

Ding Ning N, Sun Chang C, Wang Haotian H, Lv Yingchun Y et al.

Polycystic ovary syndrome (PCOS) represents a prevalent and clinically significant reproductive-endocrine disorder among women of childbearing age. While dietary interventions, regular physical activity, and targeted lifestyle modifications have been validated to confer therapeutic benefits for PCOS management, polysaccharides key bioactive components of higher plants with extensive distribution throughout the plant and animal kingdoms exhibit distinct pleiotropic bioactivities, including anti-inflammatory, immunomodulatory, hypoglycemic, lipid-lowering, and anti-obesogenic properties. In the context of PCOS treatment, these natural macromolecules hold considerable promise for alleviating clinical manifestations, ameliorating insulin resistance and obesity, attenuating inflammatory responses, and restoring sex hormone homeostasis. Cumulative evidence from preclinical and clinical studies has demonstrated that polysaccharides can improve menstrual irregularities, reduce body weight, lower blood glucose and serum testosterone levels, and suppress aberrant inflammation. The present review systematically summarizes the multifaceted effects of diverse polysaccharide compounds on PCOS, aiming to provide insights into their potential as complementary therapeutic agents for this complex disorder.

PMID 42900350
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