Testosterone Replacement Therapy (TRT) is one of the most widely used hormonal interventions for men globally, and one of the most misunderstood. It is genuinely life-changing for men with significant hypogonadism. But it is also frequently over-prescribed for men who would respond better to approaches that preserve natural function rather than replacing it.
This guide gives you the complete picture.
What Is TRT?
TRT refers to the administration of exogenous (externally sourced) testosterone to bring circulating testosterone levels back to the physiological range. The testosterone used is synthetic but bio-identical: the same molecular structure as testosterone naturally produced by the testes.
Delivery Formats
Intramuscular or subcutaneous injections: The most common format for clinical programs. Testosterone cypionate or enanthate is typically injected weekly or twice weekly to maintain stable blood levels.
Testosterone gels and creams: Applied daily to the skin. Lower compliance burden than injections but can transfer to partners and family members through skin contact.
Testosterone pellets: Implanted subcutaneously every three to six months. Provide very stable levels but require a minor procedure.
Testosterone patches: Applied to skin daily. Less commonly used due to skin reactions.
Who Is TRT Appropriate For?
TRT is most clearly indicated for men with:
- Confirmed low total testosterone (below 300 ng/dL) on two morning measurements
- Symptoms consistent with hypogonadism (reduced libido, fatigue, loss of muscle mass, mood changes)
- Primary hypogonadism (testicular failure) or severe secondary hypogonadism not responsive to natural stimulation protocols
TRT may also be appropriate for men with borderline levels and significant symptomatic burden, where quality of life is substantially impaired.
The Significant Consideration: Fertility
The most important caveat about TRT: exogenous testosterone suppresses the body's natural production via feedback to the hypothalamus and pituitary. Specifically, TRT suppresses FSH, which is required for sperm production.
Men who start TRT typically experience a significant reduction in sperm count within three to four months. For many, this becomes azoospermia (zero sperm). While fertility can often be restored after stopping TRT, this is not guaranteed and may take 6 to 24 months.
Men who want to preserve fertility should not start TRT without discussing fertility-sparing alternatives with a physician.
The Significant Consideration: Lifelong Commitment
Once started, TRT typically creates physiological dependence. The testes' natural production capacity may decline during exogenous testosterone use, sometimes permanently. Many men who start TRT find that stopping returns them to levels below their pre-treatment baseline.
This is not a reason to avoid TRT if it is the right intervention. But it is a reason to exhaust fertility-preserving and natural production options first, particularly for younger men.
Peptide Alternatives That Preserve Natural Testosterone Production
For men with secondary hypogonadism (pituitary or hypothalamic dysfunction) or borderline low levels with intact testicular function, several peptide approaches stimulate natural testosterone production without the suppression of TRT:
- Kisspeptin: Directly activates hypothalamic GnRH release, stimulating the full HPG axis and increasing LH, FSH, and testosterone naturally
- Enclomiphene: A selective oestrogen receptor modulator (SERM) that blocks oestrogen feedback at the hypothalamus, increasing LH and FSH and driving natural testosterone production
- Ipamorelin with CJC-1295: Growth hormone secretagogues that improve the GH-IGF-1 axis, indirectly supporting testosterone through improved metabolic function and body composition
These approaches preserve fertility and the body's own production capacity, making them particularly valuable for men under 45 who are not yet ready for lifelong TRT.
Monitoring During TRT
TRT requires regular monitoring to ensure:
- Testosterone levels are in the optimal (not supraphysiological) range
- Haematocrit does not exceed safe levels (TRT stimulates red blood cell production)
- Oestradiol is not elevated excessively (testosterone is partially converted to oestrogen via aromatase)
- PSA (prostate-specific antigen) is tracked annually in men over 45
At Longegra, monitoring panels are included in all testosterone programs at three-month intervals.
Frequently Asked Questions (FAQs)
The cardiovascular safety of TRT has been the subject of significant research. The TRAVERSE trial (2023) demonstrated that TRT in older men with hypogonadism and high cardiovascular risk did not increase the rate of major cardiovascular events. Long-term safety is considered acceptable under appropriate monitoring.
