hCG and Testosterone Replacement Therapy
Human chorionic gonadotropin (hCG) is a hormone that mimics luteinising hormone (LH) in the body and is sometimes used alongside testosterone replacement therapy (TRT).
While TRT can help restore testosterone levels, it can also suppress the body's natural testosterone production and reduce fertility. A specialist may consider hCG to support testicular testosterone production in selected men, but adding it to TRT does not guarantee preserved sperm production or fertility.
Why is hCG used with TRT?
Testosterone replacement therapy can interfere with the body's feedback loop that regulates hormone production. When external testosterone is introduced, the body reduces or stops its own production, including suppressing luteinising hormone (LH) and follicle-stimulating hormone (FSH). This can lead to:
- Testicular atrophy: The testicles may shrink due to lack of stimulation.
- Infertility: Sperm production may significantly decline or stop altogether.
- Reduced intratesticular testosterone: TRT increases serum testosterone but can reduce levels within the testicles, which are essential for sperm development.
hCG acts like LH and stimulates testosterone production within the testicles. Sperm production also depends on FSH and other factors. Treatment for infertility may require a different hormone plan, semen analysis and specialist care; continuing TRT with hCG does not reliably prevent infertility.
How is hCG used in TRT?
hCG is given by injection under an individual treatment plan. The product supplied may change, so its strength, route, preparation, storage and use-by period must be checked against the exact pack and dispensing instructions. Do not copy mixing or dosing instructions from another brand or an online TRT schedule.
- During TRT: A specialist may consider hCG for selected patients after discussing the limitations of evidence and fertility goals.
- When trying to conceive: Treatment may need to change, including whether testosterone should be continued. Semen analysis helps assess sperm production.
- After stopping testosterone: Recovery varies. Any hormone treatment should follow a specialist plan rather than a self-directed “post-cycle” regimen.
Benefits of using hCG with TRT
Combining hCG with TRT can offer several benefits, particularly for men looking to maintain reproductive function:
- Testicular testosterone production: hCG can stimulate this in appropriately selected patients.
- Testicular size: Changes may improve in some men, but the response varies.
- Fertility treatment: hCG may be part of a specialist treatment plan for some causes of male infertility; it does not guarantee pregnancy or preserve fertility during TRT.
- Well-being: Improvements in mood or other symptoms are not assured and should be assessed during follow-up.
Side effects of hCG
Like any medication, hCG can cause side effects, although it is generally well tolerated. Possible side effects include:
- Injection site reactions: Redness, swelling, or irritation at the injection site.
- Headache or fatigue: Some people experience general tiredness or headaches.
- Gynaecomastia (breast tissue development): Increased oestrogen levels from excess testosterone conversion may lead to breast tissue growth in some men.
- Increased mood swings or irritability: Hormonal fluctuations may affect mood in sensitive individuals.
- In rare cases: Water retention, acne, or elevated blood pressure may occur.
Is hCG right for me?
Discuss plans for children before starting or continuing TRT. A specialist can review the cause of low testosterone, assess sperm production and explain suitable options. The licensing status and licensed indications depend on the hCG product supplied; use alongside TRT may be off-label, and an imported product may not hold a UK marketing authorisation. The pharmacy should explain the status and instructions for your actual pack.
Sources and further information
- AUA/ASRM: Diagnosis and Treatment of Infertility in Men guideline (checked 8 September 2026)
- Endocrine Society: Testosterone Therapy in Men With Hypogonadism clinical practice guideline (checked 8 September 2026)
- MHRA: Supply unlicensed medicinal products (specials) (checked 8 September 2026)
