Can single-use vials of testosterone (cypionate) be used multiple times?

Single-Use Testosterone Cypionate Vials Should Not Be Used Multiple Times

Single-use vials of testosterone cypionate should not be used multiple times due to risk of contamination and lack of preservatives designed for multiple entries. While the FDA label for testosterone cypionate indicates it comes in a "Multiple Dose Vial" with preservative (benzyl alcohol 0.9%) 1, this specifically refers to vials labeled as such, not single-use vials.

Understanding Testosterone Cypionate Formulations

Testosterone cypionate is commonly prescribed as an injectable testosterone replacement therapy with the following characteristics:

• Typically dosed at 100-200 mg every 2 weeks or 50 mg weekly via intramuscular injection 2
• Available in 100 mg/mL and 200 mg/mL concentrations 2
• Properly labeled multiple-dose vials contain preservatives (benzyl alcohol 0.9%) to prevent microbial growth 1

Single-Use vs. Multiple-Dose Vials

Single-Use Vials:

• Designed for one-time use only
• May lack adequate preservatives for multiple entries
• Risk of contamination increases with each entry
• Not validated by manufacturers for extended use

Multiple-Dose Vials:

• Specifically labeled as "Multiple Dose Vial" 1
• Contain appropriate preservatives (benzyl alcohol 0.9%) 1
• Designed to maintain sterility with multiple needle entries

Risks of Using Single-Use Vials Multiple Times

1. Contamination risk: Each needle entry increases the risk of introducing bacteria or other contaminants
2. Medication stability: Exposure to air and environmental factors may compromise medication potency
3. Safety concerns: Manufacturers have not validated single-use vials for multiple entries
4. Legal/liability issues: Using products contrary to labeling may create liability concerns

Proper Testosterone Cypionate Administration

For patients requiring testosterone cypionate therapy:

• Use only vials specifically labeled as "Multiple Dose Vial" for multiple entries 1
• Follow proper aseptic technique for all injections
• Store at 20°-25°C (68°-77°F) and protect from light 1
• Discard single-use vials after one use
• For multiple-dose vials, follow institutional policies on dating opened vials

Common Pitfalls to Avoid

• Cost-saving attempts: While testosterone cypionate can be relatively expensive, reusing single-use vials to save money poses infection risks
• Confusion between vial types: Always check labeling to confirm if a vial is designated for multiple use
• Improper storage: Even multiple-dose vials can become contaminated if not stored properly
• Extended use beyond recommendations: Even properly preserved multiple-dose vials should follow institutional policies for maximum duration of use after opening

While one older study found no contamination in properly handled multiple-dose medication vials used for extended periods 3, this does not validate the reuse of vials specifically labeled for single use. The safety profile established in that study applies only to properly designated multiple-dose vials with appropriate preservatives.