What volume (in milliliters (ml)) of a 200mg per 1ml testosterone vial is needed to administer 75mg of testosterone?

Testosterone Dose Calculation

To administer 75mg of testosterone from a 200mg/1mL vial, you need to inject 0.375 mL (or approximately 0.38 mL).

Calculation Method

The calculation is straightforward using the concentration provided on the FDA label 1:

• Concentration: 200mg per 1mL 1
• Desired dose: 75mg
• Formula: (Desired dose ÷ Concentration) = Volume needed
• Calculation: 75mg ÷ 200mg/mL = 0.375mL

Practical Administration Considerations

Syringe selection matters for accurate dosing:

• Use a 1mL syringe (tuberculin syringe) for the most accurate measurement of 0.375mL, as 3mL syringes have larger increments that make precise measurement of smaller volumes more difficult 2
• Draw with an 18-gauge needle and inject with a 21-23 gauge, 1-1.5 inch needle for intramuscular administration 2

Clinical Context for 75mg Dosing

This 75mg dose falls within evidence-based testosterone replacement ranges:

• Weekly dosing of 50-100mg provides more stable testosterone levels compared to biweekly administration 2
• A 75mg weekly dose was used as a starting point in a 52-week subcutaneous testosterone enanthate study, with dose adjustments made based on week 6 testosterone levels 3
• The 100mg weekly regimen shows significantly lower risk of hematocrit elevation above 54% (1% vs 8%) compared to 200mg biweekly dosing 4

Common Pitfalls to Avoid

• Measurement error: Using a 3mL syringe for small volumes like 0.375mL increases the risk of dosing inaccuracy; always use a 1mL syringe for doses under 1mL 2
• Air bubbles: Ensure all air is expelled from the syringe before measuring the final volume, as air bubbles can lead to underdosing 2