TRT in Australia: Injections vs Gels — Which Is Right for You?
Key Takeaways
A clinician-reviewed comparison of testosterone injections and gels available in Australia — covering PBS eligibility, pharmacokinetics, transfer risk, haematocrit, and how to choose the right delivery method.
TGA-Approved Testosterone Preparations in Australia
The Therapeutic Goods Administration has approved the following:
- Testosterone undecanoate injection (Reandron 1000®) — long-acting, every 10–14 weeks
- Testosterone enanthate injection (Primoteston Depot®) — shorter-acting, every 2–4 weeks
- Testosterone gel (Testogel®, Axiron®) — applied daily
- Compounded testosterone cream — private script from compounding pharmacy
Testosterone Injections
Reandron (Testosterone Undecanoate)
With a half-life of approximately 21 days, Reandron is administered every 10–14 weeks after a 6-week loading injection. This produces stable, consistent blood levels with minimal peaks and troughs — four clinic visits per year total. It's the most commonly prescribed TRT in Australian clinical practice.
PBS status: PBS-listed for hypogonadism when total testosterone ≤5 nmol/L on two morning tests. General patient co-payment approximately $31 per script.
Haematocrit note: Injections are more likely to elevate haematocrit than gels. Haematocrit monitoring is mandatory.
Primoteston (Testosterone Enanthate)
Half-life of 4–7 days. When administered every 2–3 weeks per product labelling, produces a supraphysiological peak followed by a trough — creating hormonal fluctuation some men find symptomatic. Also PBS-listed under the same criteria.
Testosterone Gels
Testogel and Axiron
Applied daily to skin (shoulders, upper arms, inner thighs). Serum testosterone rises within hours and returns to baseline within 24 hours if a dose is missed. Daily application provides more consistent levels than infrequent injections.
PBS status: Testogel 50mg sachets are PBS-listed under the same criteria as injectables.
Transfer risk: Gel must dry completely before skin-to-skin contact. Partners and children must avoid contact with application areas — a genuine clinical concern requiring patient education.
Haematocrit advantage: Gels produce lower erythropoietic effects than injections — preferable for men with borderline haematocrit at baseline.
Head-to-Head Comparison
| Factor | Reandron (Injection) | Primoteston (Injection) | Testogel (Gel) |
|---|---|---|---|
| Frequency | Every 10–14 weeks | Every 2–4 weeks | Daily |
| Administration | Clinic (IM) | Self or clinic | Self (topical) |
| Hormonal stability | High | Moderate | High |
| PBS listed | Yes | Yes | Yes |
| Transfer risk | None | None | Yes |
| Haematocrit effect | Higher | Higher | Lower |
| Needle required | Yes | Yes | No |
| Treatment burden | Very low | Low–moderate | Daily |
What Most Australian GPs Prescribe
Based on the national Australian TRT prescribing analysis (PMC, 2021), injections comprise approximately 50% of all TRT scripts — Reandron being the dominant choice due to its low treatment burden, PBS listing, and stable pharmacokinetics.
The Endocrine Society of Australia (MJA, 2016) and Australian Prescriber both support a patient-centred choice based on individual clinical profile, lifestyle, and preference.
References
- TGA — Medicines scheduling.
- NPS MedicineWise — Reandron 1000.
- NPS MedicineWise — Testogel 50mg.
- Katz DJ, et al. A National Analysis of Temporal Changes in Prescribing of TRT. J Urol. 2021.
- Endocrine Society of Australia — MJA position statement.
- Australian Prescriber — Low testosterone in men.
- Healthdirect Australia — Testosterone.
Ready to speak with an Australian GP about TRT?
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