Subcutaneous (SQ) vs Intramuscular (IM) Injection

While testosterone has many forms of delivery such as transdermal (cream, patches), oral (lozenges), and even nasal sprays, the gold standard is via injection. Since the 1930’s IM injection (like the flu shot) has been the most common method of administration but as more research is being done SQ (like insulin) has been proven to achieve steady states of testosterone. Additional benefits of SQ administration include less discomfort due to using a smaller needle, steadier states of testosterone (due to improved toleration of more frequent injections), and less chance of venipuncture. With IM administration the medication is usually drawn up with an 18–22 gauge needle and then injected with a 22–23 gauge needle into the thigh or hip. With SQ administration a 25-27 gauge needle is used to draw up and inject the medication into the abdominal fat or thigh. 

Testosterone is dissolved in oil most commonly grapeseed or cottonseed oil. Grapeseed oil often has a lower viscosity and is much easier to inject through a smaller needle making it a preferred choice for SQ injection. While the ease of SQ injection makes “micro-dosing” a preferred option for TRT some experts recommend that the maximum volume for SQ injection is approximately 1.5 mL and larger volumes are considered to be associated with injection pain and adverse events at the injection site. It is recommended by many TRT specialists that SQ injections of less than 0.4 ml be given at one site. Ultimately, testosterone can be given via either route and whether you choose SQ or IM comes down to personal preference. 

Steel City Men’s Health and Testosterone is a clinic that provides safe and affordable testosterone replacement therapy (TRT) to men in Pueblo, Colorado. If you have any questions or would like to schedule an appointment to discuss treatment don't hesitate to call, text, or email at [email protected] or (719) 669-4223. 

Studies:

Testosterone Therapy With Subcutaneous Injections: A Safe, Practical, and Reasonable Option

"Although studies directly comparing the safety of SC vs IM administration of testosterone esters are desirable, clinicians should consider discussing the SC route with their patients because it is easier to self-administer and has the potential to improve patient adherence."

Subcutaneous Injection Volume of Biopharmaceuticals—Pushing the Boundaries

"We conclude that injection volumes higher than 3.5 mL are worth exploring if required for the development of efficacious drug treatments."

Subcutaneous administration of testosterone A pilot study report 

"Therapy with weekly subcutaneous testosterone produced serum levels that were within the

normal range in 100% of patients for both peak and trough levels. This is the first report, which demonstrated the efficacy of delivering weekly testosterone using this cheap, safe, and less painful subcutaneous route."