How to Determine Your Starting Dose of Testosterone for TRT (With Free Dosage Calculator)

Last Updated On March 31, 2025

Starting your testosterone replacement therapy (TRT) journey can feel overwhelming, especially when determining the right dose. Many patients wonder, “What testosterone dose is right for me?” While your healthcare provider will typically recommend your dosage, understanding how dosing works can help you become a more informed patient and have more productive conversations about your treatment.

This beginner-friendly guide explains how to understand TRT dosing calculations, ensuring you’re well-informed about your protocol.

Our free TRT Dosage Calculator Tool can help you estimate typical weekly doses for TRT.

Understanding Dosage Basics

What is a Starting Dose?

A starting dose is the initial amount of testosterone prescribed to begin your TRT protocol. It’s typically adjusted over time based on symptoms, bloodwork, and individual needs. A common starting range is 100-200 mg per week, with many providers beginning at around 125-150 mg weekly. Some physicians use a weight-based approach of approximately 1–2 mg of testosterone per kilogram of body weight per week.

Why Concentration Matters

Testosterone vials are labeled with their concentration, typically 200mg/ml or 250mg/ml in the US. This tells you how much testosterone is present in 1 milliliter (ml) of liquid. Understanding this is critical for determining how much to inject.

How to Calculate Your Dose

Step 1: Understand Your Prescribed Dose

Your doctor will prescribe a specific weekly dose. Common examples include:

• 125 mg per week
• 150 mg per week
• 200 mg per week

Step 2: Check Your Vial Concentration

The concentration ensures accurate measurement. For example:

• A vial labeled 200mg/ml contains 200 mg of testosterone in 1 ml of liquid.
• A vial labeled 250mg/ml contains 250 mg of testosterone in 1 ml of liquid.

Step 3: Calculate Your Injection Volume

To determine how much to draw into your syringe:

Injection volume (ml) = Prescribed dose (mg) ÷ Concentration (mg/ml)

Step 4: Divide the Dose (If Recommended)

Many TRT protocols split the weekly dose into smaller injections for better absorption and stable blood levels.

Injection Frequency

Frequent, smaller doses help maintain steady testosterone levels and minimize side effects. Common approaches include:

• Once weekly: Simplest approach, but may lead to more fluctuations
• Twice weekly: Most common frequency, balancing convenience and stability
• Every other day (EOD): Provides very stable levels but requires more frequent injections

Simple Calculation Examples

Example 1: Most Common Protocol (125mg weekly from 250mg/ml)

• Prescribed dose: 125 mg per week
• Vial concentration: 250 mg/ml
• Simple calculation: 125 ÷ 250 = 0.5 ml per week
• This means you draw up exactly half (0.5ml) of a standard 1ml syringe

If splitting into two injections per week:

• 0.5ml ÷ 2 = 0.25ml per injection
• This means you draw up exactly one-quarter (0.25ml) of a standard 1ml syringe, twice per week

Example 2: Standard Protocol (200mg weekly from 200mg/ml)

• Prescribed dose: 200 mg per week
• Vial concentration: 200 mg/ml
• Simple calculation: 200 ÷ 200 = 1.0 ml per week
• This means you draw up exactly one full 1ml syringe

If splitting into two injections per week:

• 1.0ml ÷ 2 = 0.5ml per injection
• This means you draw up exactly half (0.5ml) of a standard 1ml syringe, twice per week

Example 3: Lower Dose Protocol (100mg weekly from 200mg/ml)

• Prescribed dose: 100 mg per week
• Vial concentration: 200 mg/ml
• Simple calculation: 100 ÷ 200 = 0.5 ml per week
• This means you draw up exactly half (0.5ml) of a standard 1ml syringe

Safety Guidelines

• Follow Your Provider’s Instructions: Always adhere to the dosage prescribed by your healthcare provider.
• Adjust Only Under Supervision: Changes to your protocol should be made in consultation with your doctor.
• Use Bloodwork as a Guide: Regular testing of Total Testosterone, Free Testosterone, and SHBG levels helps refine your dose.
• Monitor Side Effects: Watch for symptoms such as mood swings, acne, or water retention, which may indicate the need for adjustments.

For Self-Managed TRT

If you’re considering or currently practicing self-managed TRT, additional precautions apply:

• Start Low: Begin with a conservative dose of 100-125 mg per week.
• Adjust Slowly: If necessary, adjust by no more than 10-25 mg (roughly 10% of your starting dose) after at least 6-8 weeks.
• More Frequent Testing: Test blood levels more regularly until you achieve stability.

Dosage Calculator

Use our free TRT Dosage Calculator Tool to help you calculate your weekly injection volumes based on your prescribed dose.

Key Takeaways

• Understanding your TRT dosage calculation helps you become a more informed patient.
• Weekly doses are typically split into 2-3 injections to stabilize testosterone levels.
• Regular bloodwork is essential for optimizing your protocol.
• Working with a knowledgeable healthcare provider ensures the safest and most effective approach.

By understanding these dosing principles, you can have more productive conversations with your healthcare provider and better monitor your TRT progress.