In North America, the leaflet that comes with injectable testosterone says that T should only be injected intramuscularly, but a growing number of endocrinologists are recommending subcutaneous injections as a convenient, effective alternative.
What Are Subcutaneous Injections?
aka. SC, SQ, sub-cu, sub-Q or subcut.
The difference between sub-q and IM injections is basically the depth of the injection. A subcutaneous injection is administered into the layer of skin directly below the dermis and epidermis, with a depth of 4-8mm (0.15″-0.2″), while an IM injection is administered into muscle, with a depth of at least 2.5cm (1″.) Subcutaneous injection sites include belly, upper arms, and thighs.
Ryan Sallans has a helpful video demonstrating how to do a sub-q testosterone injection:
The Case for Sub-Q
In a study initiated by the well-known endocrinologist, Dr. Norman Spack, researchers sought to assess the safety and absorption of subcutaneous testosterone therapy in FTM trans men and hypogonadal cis gender men. They found subcutaneous administration of testosterone to be a safe, effective, and affordable alternative to IM injection.
T levels were well within the therapeutic range varying from 320-824 ng/dL (mean 608± 82SE). No adverse reactions at the site of injection or otherwise were reported or observed. The injections were easily self-administered except for one patient who was blind. Initial data from our study are promising regarding the SC administration of T. SC T was well tolerated and produced therapeutic serum concentrations at doses generally lower than required for IM injections. These data will provide a foundation for additional studies of pharmacokinetics, efficacy and safety to hopefully characterize SC T as a safe, convenient, and affordable alternative to IM injections.
– Evaluation of the efficacy of subcutaneous administration of testosterone in female to male transexuals and hypogonadal males. Endocr Rev, Vol. 34 (03_MeetingAbstracts): MON-594.
Benefits of Sub-Q
- Stable T levels often at doses lower than required for IM injections, reducing patient drug costs.
- Injections are more easily self-administered than IM injections. Not just a convenience, self-administered injections are also a money saver for those who have been paying to have injections administered at a clinic.
- Shorter needles used with subcutaneous injection are ideal for trans teens, with their smaller musculature.
- No build up of muscular scar tissue as with IM injections.
- No risk of sciatic nerve injury from dorsogluteal IM injections.
It’s likely that more and more trans guys will be employing sub-q administration of T, particularly those starting HRT as teens. However, more studies investigating absorption rate, half-life, conversion to Estriadol, and affect on DHT levels are still needed to solidify these latest findings.
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