How often can a male on testosterone replacement therapy (TRT) take anastrozole (aromatase inhibitor) per week?

Anastrozole Dosing for Males on Testosterone Replacement Therapy

For males on testosterone replacement therapy (TRT), anastrozole should be administered at 0.5 mg three times per week when estradiol levels are elevated (>40-60 pg/mL with symptoms or >60 pg/mL regardless of symptoms) 1.

When to Use Anastrozole with TRT

Anastrozole is indicated in men on TRT who develop:

• Estradiol levels >60 pg/mL regardless of symptoms
• Estradiol levels between 40-60 pg/mL with symptoms such as:
  • Gynecomastia
  • Fluid retention
  • Mood changes
  • Sexual dysfunction related to high estradiol

Dosing Protocol

The most effective and evidence-based dosing regimen for anastrozole in men on TRT is:

• Starting dose: 0.5 mg three times per week 1
• Alternative dosing: 1 mg twice weekly 2
• For severe cases: 1 mg daily (though this higher dose is rarely needed) 2

Monitoring and Adjustment

1. Measure baseline estradiol levels before starting anastrozole
2. Recheck estradiol levels 4-6 weeks after initiating therapy
3. Target estradiol range: 20-30 pg/mL (not too low to maintain bone health)
4. Monitor testosterone levels to ensure they remain in therapeutic range

Clinical Efficacy

Research shows that anastrozole effectively:

• Reduces estradiol levels from median 65 pg/mL to 22 pg/mL 1
• Maintains therapeutic testosterone levels 3
• Extends the duration between testosterone pellet insertions from 128 days to 198 days when used in combination 3
• Increases endogenous testosterone production in hypogonadal men 2

Potential Benefits

• Prevents estrogen-related side effects of TRT
• Maintains stable testosterone levels
• May improve semen parameters in subfertile men 4
• Does not adversely affect lipid profiles or cardiovascular risk markers 5

Cautions and Considerations

• Avoid reducing estradiol levels too much (<10 pg/mL) as this may negatively impact bone health
• Monitor bone mineral density if using long-term
• Not recommended for men trying to conceive in the near term 6
• Use with caution in men with osteoporosis or significant bone loss 7

Algorithm for Anastrozole Use in TRT

1. Start TRT without anastrozole
2. Check estradiol levels after 2-3 months of TRT
3. If estradiol >60 pg/mL or 40-60 pg/mL with symptoms:
   • Start anastrozole 0.5 mg three times weekly
4. Recheck estradiol after 4-6 weeks
5. Adjust dose:
   • If estradiol still >40 pg/mL: Increase to 1 mg twice weekly
   • If estradiol <15 pg/mL: Decrease to 0.5 mg twice weekly
   • If estradiol 15-30 pg/mL: Maintain current dose

By following this protocol, you can effectively manage estradiol levels while maintaining the benefits of testosterone replacement therapy.