Pediatric Testosterone Therapy FDA Approvals, Evidence Gaps, and Care Standards

Pediatric Testosterone Therapy FDA Approvals, Evidence Gaps, and Care Standards

Which testosterone treatments are actually FDA-approved for adolescents, and why most others are adult-only. Understand growth plate risks, monitoring, and where new studies may lead.

Estimated reading time: 8 minutes

Key takeaways

• Only testosterone enanthate injections and subcutaneous pellets carry FDA indications related to delayed puberty in carefully selected males or for hypogonadism occurring before puberty; most modern TRT products are adult-only.
• These pediatric indications predate current trial standards and would not meet today’s evidentiary expectations.
• Labels warn of accelerated bone age and premature epiphyseal closure; bone-age X-rays about every six months are recommended when used in adolescents.
• Kyzatrex (oral testosterone undecanoate) has an FDA postmarketing requirement to study pediatric males 12 to <18—an effort to fill evidence gaps.
• Clinicians and families should confirm the narrow FDA-recognized indications, involve pediatric endocrinology, monitor growth plates, and avoid off-label pediatric use of other formulations.

Testosterone therapy in adolescents sits at a careful intersection of endocrinology, growth, and regulation. The FDA does allow select testosterone formulations for pediatric use—but only in narrow circumstances and based largely on historical approvals that would not meet today’s evidentiary standards. This article reviews what’s actually FDA‑approved for delayed puberty or pediatric hypogonadism, why the evidence base looks different from modern trials, the specific risks relevant to adolescents, and what to watch as new pediatric studies are required for newer products.

What the FDA Actually Approves for Pediatric Use Today

Despite the broad public conversation about testosterone therapy, pediatric approvals are narrow:

• Testosterone enanthate (TE) injections and subcutaneous testosterone pellets have FDA labeling that permits use “for stimulating puberty in carefully selected males with clear evidence of delayed puberty,” or for hypogonadism occurring prior to puberty.
• The labels emphasize cautious patient selection and monitoring. They recommend bone‑age (hand/wrist) radiographs about every six months during treatment to watch for accelerated bone maturation.
• In contrast, nearly all other testosterone replacement therapy (TRT) products—transdermal gels and patches, short‑acting nasal formulations, injectable testosterone undecanoate, and oral testosterone undecanoate—explicitly state that safety and efficacy have not been established in males younger than 18 years. In other words, they’re adult‑only, with pediatric use not supported by current labeling.

This matters because clinical practice and direct‑to‑consumer marketing for adult hypogonadism can be mistaken for a green light in adolescents. It isn’t. For pediatric patients, FDA‑recognized options are limited to TE injections and pellets, and even those require vigilant growth monitoring and specialist oversight.

Why These Legacy Pediatric Approvals Don’t Look Like Modern Trials

The TE and pellet approvals trace back to an earlier regulatory era. Historically, the concept was straightforward: if a child has hypogonadism or markedly delayed puberty, androgen replacement can stimulate the development of secondary sexual characteristics. That principle underpinned the approvals—without the type of well‑controlled, adequately powered pediatric efficacy and safety trials that the FDA typically expects today.

Key context:

• Many testosterone products were introduced before the Drug Efficacy Study Implementation (DESI) modernized standards for proof of efficacy. As a result, historical approvals leaned more on pharmacology and clinical experience than on contemporary randomized trial designs.
• Modern adult TRT approvals tend to rely on pharmacokinetic (PK) “normalization”—showing that a product achieves serum testosterone levels within adult reference ranges—rather than on hard clinical outcomes. In pediatrics, however, growth, maturation timing, bone health, and long‑term development carry different stakes and require dedicated study.
• Because the original pediatric approvals didn’t go through today’s trial rigor, we lack robust, contemporary data on long‑term growth outcomes, optimal regimens across hypogonadism subtypes, or comparative effectiveness among formulations in adolescents.

In short, the existence of a pediatric indication for TE and pellets reflects regulatory history, not a comprehensive modern evidence base.

Risks Unique to Adolescents: Bone Age Acceleration and Growth Plates

The clearest label warning for adolescent testosterone exposure is the risk of accelerated bone maturation leading to premature epiphyseal closure. In practical terms, the growth plates in long bones can fuse earlier than they otherwise would, potentially limiting final adult height.

What this means for care:

• Monitoring is not optional. Bone‑age X‑rays roughly every six months are part of responsible care when using TE injections or pellets in adolescents. Radiographic evidence of advancement beyond expected maturity may prompt reassessment.
• “Improper use” is a real concern. Initiating therapy in the absence of clear hypogonadism or carefully selected delayed puberty—or using supraphysiologic amounts—raises the risk of rapid skeletal maturation without proportional linear growth.
• Individual variation matters. Adolescents are in a dynamic developmental window with evolving endocrine, skeletal, and psychosocial trajectories. Decisions about whether and when to start or adjust therapy require pediatric endocrinology expertise and careful discussion of benefits, risks, and uncertainties.

Other androgen‑related adverse effects (like acne, mood changes, or hematologic shifts) may occur, but the growth plate risk is uniquely consequential for lifelong stature and underpins the strict monitoring recommendations.

Kyzatrex’s Pediatric PMR: A Modern Study to Close a Long‑Standing Gap

Kyzatrex (oral testosterone undecanoate) was approved by the FDA in 2022 for adult hypogonadism. Importantly for pediatrics, its approval includes a postmarketing requirement to conduct a pediatric trial in males ages 12 to <18 with primary or secondary hypogonadism. The PMR milestones specified at approval were:

• Study protocol submission: June 2023
• Trial completion: December 2023
• Final report submission: March 2024

Why this matters:

• It’s a deliberate move by the FDA to generate modern pediatric data where little currently exists, particularly for oral testosterone formulations.
• A dedicated pediatric study—if well designed and completed—could clarify dosing strategies, safety signals (including growth plate impacts), PK targets appropriate for adolescents, and short‑term clinical effects (e.g., Tanner staging progress).
• Even with new data, a pediatric indication is not guaranteed. The FDA could conclude that safety/efficacy remain insufficient, that benefits apply only to specific subgroups, or that additional studies are needed.

As of the 2022 approval, results were not available. Families and clinicians should check the latest FDA communications to confirm whether the PMR has been completed, what it found, and whether it changes labeling or recommendations.

Practical Implications for Clinicians and Families

Given the tight regulatory framework and evidence gaps, a conservative, standards‑based approach is warranted.

If a pediatric patient is being evaluated for delayed puberty or suspected hypogonadism:

• Confirm the diagnosis with a pediatric endocrinologist. The differential for delayed puberty is broad, and timing of maturation varies. Specialist input helps determine whether observation, non‑androgen strategies, or androgen therapy is appropriate.
• Verify the FDA‑approved pediatric options. As of now, only TE injections and subcutaneous pellets have pediatric‑relevant indications for stimulating puberty in carefully selected cases. Most other TRT formulations explicitly lack pediatric safety/efficacy data.
• Discuss growth plate monitoring upfront. Bone‑age radiographs about every six months are part of the label recommendations to mitigate the risk of premature epiphyseal closure.
• Align expectations with uncertainties. Short‑term progression of secondary sexual characteristics may be achievable, but the long‑term impact on adult height, cardiometabolic health, fertility, and psychosocial outcomes remains under‑studied by modern standards.
• Approach off‑label pediatric use of adult‑only products with caution. The absence of established safety and efficacy is meaningful; approval in adults does not imply suitability for adolescents.
• Reassess regularly. Adolescence is a moving target. Periodic review of growth velocity, bone age, Tanner staging, labs, and psychosocial factors supports course corrections as needed.

Questions families can bring to a pediatric endocrinology visit:

• Is my child’s presentation consistent with constitutional delay, or is there evidence of primary/secondary hypogonadism?
• If testosterone is considered, why TE injections or pellets versus other formulations? What’s FDA‑approved for pediatric use?
• How will bone maturation and growth be monitored? What would trigger a change in plan?
• What short‑term benefits should we expect, and what are the known and unknown risks?
• How does the plan align with my child’s developmental, social, and athletic life?
• If newer data (e.g., from required pediatric studies) become available, how would that impact the treatment approach?

For adult‑focused TRT clinics, including services like Taurus Meds, the practical boundary is clear: pediatric therapy requires pediatric endocrinology expertise, pediatric‑specific monitoring, and adherence to FDA‑recognized indications. Adult TRT workflows and formulations shouldn’t be repurposed for adolescents.

How Modern Standards May Evolve

Two regulatory dynamics will shape the future of pediatric TRT:

• Pediatric research requirements and incentives: For newer products approved in adults, the FDA can require pediatric assessments or studies if a therapy might be relevant to children. That’s the case with Kyzatrex. As more data emerge, labeling could expand—or remain restricted—based on benefits and risks demonstrated in adolescents.
• Outcome expectations: Pediatric trials increasingly emphasize clinically meaningful outcomes—growth trajectories, bone age progression relative to chronological age, pubertal staging, safety signals—rather than PK alone. This could raise the evidentiary bar for future pediatric indications across formulations.

Key open questions:

• Will modern pediatric trials confirm safe, effective regimens that preserve adult height potential?
• Are certain hypogonadism subtypes better suited to specific formulations or schedules?
• Can findings from adult PK‑normalization translate safely to adolescents, or do youth‑specific targets and endpoints need to be defined?
• What is the long‑term safety profile of contemporary formulations started during adolescence?

A Balanced Conclusion

Pediatric TRT is not a simple extension of adult practice. Today, only testosterone enanthate injections and testosterone pellets hold FDA indications relevant to delayed puberty in carefully selected cases, and those approvals stem from an earlier regulatory era. The label‑mandated focus on bone‑age monitoring reflects a real and potentially irreversible risk: premature closure of the growth plates.

Newer products approved for adults—like Kyzatrex—are now carrying postmarketing pediatric study requirements, which is a welcome step toward an evidence base aligned with modern standards. Until high‑quality pediatric data are available and acted upon through updated labeling, clinicians and families should stay within the narrow FDA‑recognized indications, avoid off‑label pediatric use of adult‑only formulations, and partner closely with pediatric endocrinologists.

For families exploring care options, the safest path is a measured one—grounded in diagnosis, respectful of growth biology, and responsive to new data as it emerges.

Disclaimer

This article is for informational purposes only and is not a substitute for professional medical advice. Testosterone therapy in adolescents should be managed by qualified healthcare professionals—ideally pediatric endocrinologists—based on individual clinical circumstances and current FDA‑approved labeling.

Sources

• FDA Testosterone Information
• Kyzatrex (testosterone undecanoate) NDA Summary Review (2022)
• FDA Androgen-Related Safety Communication (PDF)