What is the recommended protocol for subcutaneous (subcu) injection of testosterone cypionate, including type of needles and syringes?

Subcutaneous Testosterone Cypionate Injection Protocol

For subcutaneous testosterone cypionate injections, use a 25-27 gauge needle with a 5/8-inch or 1/2-inch length on a 1 mL insulin syringe, injecting into the abdomen, thigh, or posterior aspect of the upper arm with the skin pinched to ensure proper subcutaneous placement.

Injection Equipment

• Syringe: 1 mL insulin or tuberculin syringe 1
• Needle: 25-27 gauge with 5/8-inch or 1/2-inch length 1, 2
• Non-removable needle preferred for safety and accuracy 1

Injection Sites

Several appropriate sites can be used for subcutaneous testosterone administration:

1. Abdomen:

   • Within 1 cm above symphysis pubis
   • Within 1 cm below lowest rib
   • At least 2 fingerbreadths away from umbilicus
   • Laterally at the flanks 1

2. Thigh:

   • Upper third anterior lateral aspect 1

3. Upper Arm:

   • Middle third posterior aspect 1

4. Buttocks/Flanks:

   • Posterior lateral aspect of upper buttocks 1

Injection Technique

1. Preparation:

   • Clean injection site with alcohol swab in circular motion from center outward 1
   • Allow site to dry completely before injection
   • Draw exact prescribed dose of testosterone cypionate into syringe

2. Administration:

   • Pinch skin to lift it away from muscle 1
   • Insert needle at 90° angle through skin 1
   • Aspirate syringe to check for blood return (optional safety step) 1
   • If blood appears, remove needle, discard syringe, and prepare new dose
   • Inject medication slowly 1
   • Remove needle and apply light pressure to injection site for about 1 minute 1

Dosing Considerations

• Typical starting dose: 50-75 mg weekly 2, 3
• Dose can be adjusted between 50-150 mg based on serum testosterone levels 2
• Weekly administration provides more stable testosterone levels than biweekly or monthly injections 2, 4

Advantages of Subcutaneous vs. Intramuscular

• Less painful than intramuscular injections 2, 4
• Easier self-administration 2
• Similar pharmacokinetic profile to IM injections 5, 4
• Patients report lower pre-injection anxiety and post-injection pain 4

Potential Complications and Management

• Minor local reactions may occur in approximately 14% of patients but are typically transient 2
• Proper rotation of injection sites helps prevent lipohypertrophy 1
• Avoid injecting into areas with visible veins, lesions, scars, or bruises 1

Site Rotation

• Document and rotate injection sites systematically
• Allow at least 1 inch between successive injection sites
• Establish a rotation pattern (e.g., clockwise around abdomen) to prevent tissue damage 1

Storage and Handling

• Store testosterone cypionate vials at room temperature
• Check expiration date before each use
• Mark opening date on multidose vials
• Discard needles in appropriate sharps container

This protocol provides a safe and effective method for subcutaneous testosterone administration, with evidence showing comparable efficacy to traditional intramuscular injections but with improved patient comfort and satisfaction.