Initial Treatment for Adult Hypogonadism
The initial treatment for adult hypogonadism should begin with lifestyle modifications (weight loss and exercise) in obese/metabolic patients, followed by testosterone therapy (TTh) as first-line medical treatment in symptomatic men with confirmed low testosterone, using transdermal formulations or long-acting injectables as preferred options 1.
Treatment Algorithm
Step 1: Address Reversible Causes First
Before initiating medical therapy, the 2025 EAU guidelines emphasize:
- Eliminate interfering medications/substances that suppress the hypothalamic-pituitary axis
- Modify metabolic conditions: obesity, underweight, or metabolic disturbances
- Lifestyle interventions are essential but provide only modest testosterone increases (1-2 nmol/L) 1
Step 2: Determine Fertility Status (Critical Decision Point)
This fundamentally changes your treatment approach:
If fertility is desired:
- Testosterone therapy is absolutely contraindicated 1
- For secondary hypogonadism: Use gonadotropin therapy (hCG + FSH combination) as standard treatment 1
- This maintains testosterone levels while preserving spermatogenesis
If fertility is NOT desired:
- Proceed to testosterone replacement therapy (see below)
Step 3: Testosterone Therapy Selection
The 2025 EAU guidelines recommend multiple formulations based on patient characteristics 1:
Preferred first-line options:
- Transdermal testosterone gels - recommended for treatment initiation 2
- Long-acting injectable testosterone (testosterone undecanoate) - best efficacy/safety profile 3
Alternative formulations:
- Injectable testosterone enanthate or cypionate
- Transdermal patches
- Buccal tablets
- Testosterone pellets
- Oral testosterone undecanoate
The 2018 Endocrine Society guidelines recommend maintaining serum testosterone in the mid-normal range for healthy young men 4.
Key Clinical Considerations
Combining Lifestyle and Medical Therapy
The evidence suggests that combining lifestyle modifications with testosterone therapy yields better outcomes than either alone in symptomatic patients 1. Don't wait for lifestyle changes to fail completely before initiating TTh in symptomatic men with confirmed hypogonadism.
Absolute Contraindications to Testosterone Therapy
- Men seeking fertility 1
- Active or treated male breast cancer 1
- Untreated prostate cancer 2
- Severe heart failure 2
Relative Contraindications
Initial Monitoring Protocol
The 2018 Endocrine Society provides specific monitoring timelines 4:
- First evaluation: 3-6 months after initiation (depending on formulation)
- Measure testosterone and hematocrit
- Assess symptom response and adverse effects
- Annual monitoring thereafter: testosterone, hematocrit, PSA (if chosen for prostate monitoring)
Expected Outcomes with Strong Evidence
The 2025 EAU guidelines provide strength ratings for TTh outcomes 1:
- Sexual function improvement (particularly mild ED) - Strong recommendation
- Body composition improvement (reduced fat mass, increased lean mass) - Well-established 3
- Bone mineral density improvement (particularly lumbar spine) - Established benefit 3
Outcomes with Weak/Conflicting Evidence
- Weight reduction and cardiometabolic status - NOT recommended as primary indication 1
- Cognition, vitality, physical strength in aging men - NOT recommended 1
- Glycemic control in diabetes - conflicting evidence 3
Common Pitfalls to Avoid
- Starting TTh without confirming fertility intentions - This is irreversible suppression of spermatogenesis with long-acting formulations
- Using TTh in eugonadal men - Strong recommendation against this 1
- Failing to address lifestyle factors - These should be initiated concurrently, not sequentially
- Inadequate pre-treatment screening - PSA and DRE should be performed in men >40 years before initiating TTh 2
- Not monitoring hematocrit - Stop therapy if hematocrit >54% and evaluate for hypoxia/sleep apnea 4
The strength of this algorithmic approach is based on the most recent 2025 EAU guidelines 1, which represent the highest quality and most current evidence available, supported by the 2018 Endocrine Society guidelines 4 for specific monitoring protocols.