Dr. Kumar’s Take
This retrospective cohort study looked at 63 female-to-male transgender adults who chose subcutaneous testosterone, and every one of them reached serum testosterone in the normal male range. That is a straightforward result: the shot does not have to go deep into muscle to work. The preference data is what interests me clinically. Of the 22 patients who had been on intramuscular therapy and switched, all 22 preferred the subcutaneous route and none wanted to go back. For anyone facing years of injections, comfort is not a small thing. It drives whether people stay on therapy at all.
Key Takeaways
✔ All 63 patients reached serum testosterone within the normal male range.
✔ Doses ranged from 50 to 150 mg weekly, with a median of 75/80 mg.
✔ Of 22 patients who switched from intramuscular, all 22 preferred subcutaneous; none preferred intramuscular.
✔ Local reactions were minor and transient, reported in 9 of 63 patients.
Actionable Tip
If you are on testosterone and find intramuscular shots painful or hard to arrange, ask your doctor whether subcutaneous injection is an option for you. In this cohort, the starting dose was 50 mg weekly, adjusted as needed to bring serum total testosterone into the normal male range.
Study Snapshot: What the JCEM Study Examined
A retrospective cohort study published in the Journal of Clinical Endocrinology and Metabolism reviewed subcutaneous testosterone as an alternative to intramuscular injection. The setting was an outpatient reproductive endocrinology clinic at an academic medical center. Sixty-three female-to-male transgender patients over age 18 who elected subcutaneous testosterone for sex transition were included, 53 of them premenopausal. Patients received testosterone cypionate or enanthate weekly, starting at 50 mg, with the dose adjusted if needed to reach serum total testosterone in the normal male range. The investigators tracked free and total testosterone, total estradiol, masculinization, and injection site reactions.
Results: Testosterone Levels, Safety, and Preference
- Target levels achieved: Serum testosterone within the normal male range was reached in all 63 patients, on doses of 50 to 150 mg (median 75/80 mg).
- Worked across body sizes: Therapy was effective across a body mass index range of 19.0 to 49.9 kg/m2.
- Hormonal effects: Among the 53 premenopausal patients, 51 achieved amenorrhea and 35 achieved serum estradiol below 50 pg/mL.
- Patient preference: Twenty-two patients switched from intramuscular to subcutaneous. Two had a mild preference and 20 had a marked preference for subcutaneous. None preferred intramuscular.
- Safety: Minor and transient local reactions were reported in 9 of 63 patients.
Why Subcutaneous Testosterone Makes Sense
The practical argument is in the abstract itself. Intramuscular injections can involve significant discomfort and may require arranging for someone else to give them. A subcutaneous injection is easier to self-administer, and in this cohort it still moved serum testosterone into the normal male range in every patient, across a wide span of body mass index. When effectiveness holds and burden drops, the burden is worth taking seriously.
Clinical Fit and Practical Notes
- Who this evidence covers: Adult female-to-male transgender patients electing subcutaneous testosterone in an outpatient endocrinology clinic. That is the population studied, and it is worth keeping in mind when applying the findings.
- Monitoring: In this study, serum total testosterone guided dose adjustment, and free testosterone and total estradiol were also measured. Your clinician decides the monitoring plan for your situation.
- Dosing: Weekly injection starting at 50 mg, titrated within the 50 to 150 mg range to bring levels into the normal male range.
Related Studies and Research
Podcast: Testosterone Replacement Therapy Explained: Anchor episode on dosing, monitoring, and therapy choices.
Muscular Responses to Testosterone Differ by Route: Which routes provide the greatest muscle and strength benefit.
Harmonized Testosterone Reference Ranges: Standardized cutoffs for diagnosing low testosterone.
TRT and Sexual Function in Hypogonadism: Clinical data on restoring sexual health and reducing symptoms.
Frequently Asked Questions
Did subcutaneous testosterone reach male-range levels?
Yes. All 63 patients achieved serum testosterone within the normal male range on doses of 50 to 150 mg weekly.
Did patients prefer it to intramuscular injection?
Among the 22 patients who switched from intramuscular to subcutaneous, all 22 preferred subcutaneous: 2 mildly and 20 markedly. None preferred intramuscular.
Were there injection site problems?
Minor and transient local reactions were reported in 9 of the 63 patients.
Does it work if you carry more weight?
Therapy was effective across a body mass index range of 19.0 to 49.9 kg/m2 in this cohort.
Conclusion
This was a retrospective cohort study, not a randomized trial, so it shows what happened in one clinic’s practice rather than proving one route superior to the other. Within that limit, the signal is consistent: subcutaneous testosterone brought every patient into the normal male range, local reactions were minor and transient, and everyone who had tried both routes preferred the subcutaneous one. The authors concluded that subcutaneous injection is an effective, safe, and well-accepted alternative to intramuscular. I find that a reasonable read of the data.
