IM Vs SubQ Testosterone Injections Compared For TRT

When men compare IM vs SubQ testosterone injections, both methods can raise testosterone in men with diagnosed deficiency, and available evidence suggests they work comparably (Figueiredo et al., 2022). The differences are practical. They come down to needle size, how often you inject, and how steady your levels stay between doses. Subcutaneous shots use a shorter, thinner needle and produce smaller swings. Intramuscular shots go deeper and can push testosterone higher right after a dose. Neither route is better on its own. The right one depends on your lab work, your symptoms, and what you and a clinician decide together. Marek Health is a telehealth provider treating low testosterone, and its testosterone therapy programs use both routes depending on the patient.

What's the difference between IM and SubQ testosterone injections?

IM testosterone is injected into deep muscle, usually the glute or thigh. SubQ testosterone goes into the fat layer just under the skin, often the abdomen. Both deliver the same medication. The route changes needle depth, how often you inject, and how high testosterone climbs between doses.

Intramuscular has been the standard for decades. Subcutaneous is newer in routine use and has grown because patients find it easier to do at home. One subcutaneous testosterone enanthate autoinjector is designed to produce smaller peaks and troughs than a typical intramuscular cycle (Choi et al., 2022). Because testosterone is a controlled medication, a licensed clinician confirms the diagnosis and sets the route.

Intramuscular (IM) injections and their trade-offs

IM testosterone tends to give predictable absorption and is the route most prescribers know best. It is also typically the least expensive injectable option (Figueiredo et al., 2022). The trade-off is a longer needle, a larger injection volume, and bigger swings for some men: a higher peak after the shot and a lower trough before the next.

That peak is not only a comfort issue. Larger hormone swings may contribute to side effects in some men, which is one reason TRT lab work and ongoing monitoring matter (Choi et al., 2022).

Subcutaneous (SubQ) injections and their trade-offs

SubQ testosterone uses a shorter, thinner needle into the fat layer, so most men find it more comfortable and easier to self-administer at home (Figueiredo et al., 2022). It usually means more frequent injections, and a few men notice mild redness at the site.

The draw for many patients is steadier levels. In one study, the subcutaneous route was associated with a more favorable side-effect profile than the intramuscular route, though this is limited, single-study evidence and results vary (Choi et al., 2022).

How do IM vs SubQ testosterone injections compare?

Held to the same measures, the two routes line up like this.

The research backs the table. In one comparison, intramuscular and subcutaneous testosterone were studied head-to-head; both raised testosterone, and the subcutaneous route was associated with a more favorable side-effect profile, though this is limited, single-study evidence (Choi et al., 2022). A review in The Journal of Clinical Endocrinology and Metabolism found that limited evidence suggests subcutaneous dosing performs comparably, with easier self-administration (Figueiredo et al., 2022). Both can work well, and the subcutaneous route may offer fewer side effects for some men.

How testosterone therapy is prescribed and monitored

A clinical evaluation comes before any injection. Diagnosing low testosterone generally relies on more than one morning blood test plus related symptoms, interpreted by a clinician (Mulhall et al., 2018). Testosterone is a Schedule III controlled substance, so the prescription follows that evaluation and is issued only when medically appropriate. A federal allowance lets clinicians prescribe by telemedicine without a prior in-person visit through December 31, 2026, though state law varies (DEA, 2025).

Monitoring is what protects you. Guidelines recommend periodic lab monitoring during therapy, with your clinician adjusting or pausing treatment if results warrant it (Bhasin et al., 2018). Route and dose follow your results, not a fixed template.

Safety guidance changed recently. In February 2025, the FDA updated every testosterone label. It added results from the TRAVERSE safety trial, kept the limit that testosterone is not approved for low levels due only to aging, removed the older boxed cardiovascular warning, and added a blood-pressure warning, so heart health stays part of monitoring (FDA, 2025). In that trial, testosterone did not increase major cardiac events compared with placebo, though it was associated with higher rates of atrial fibrillation and pulmonary embolism; the trial used a gel rather than injections (Lincoff et al., 2023). FDA-approved injectable testosterone exists for diagnosed deficiency, while compounded testosterone is not FDA-approved, and guidelines favor commercially manufactured products when possible (Mulhall et al., 2018). If fertility matters to you, discuss preservation with your provider before starting, since sperm production can fall and recovery varies.

So, is it better to inject testosterone IM or SubQ?

The short answer: it depends on you, and it is a decision to make together with your provider, not a default. Both routes can effectively treat diagnosed low testosterone when prescribed and monitored appropriately (Figueiredo et al., 2022). If steadier levels and an easier at-home routine matter most, some limited evidence suggests the subcutaneous route may suit you better (Choi et al., 2022). If you would rather inject less often, intramuscular still earns its place. What does not change is the lab confirmation and follow-up behind either choice. The method matters less than the monitoring around it, and that is the honest answer to whether IM vs SubQ testosterone injections are right for you. Marek Health builds both into science-backed care once you get started.

Disclaimer: This blog post is intended for informational purposes only and should not be considered medical advice. Always consult a healthcare professional before making changes to your health routine.

FAQs

What is the difference between IM vs SubQ testosterone injections? 

IM testosterone goes into deep muscle, while SubQ testosterone goes into the fat layer under the skin. Both use the same medication and can reach similar testosterone levels. The route changes needle size, how often you inject, and how high levels peak between doses. One subcutaneous autoinjector is designed to produce smaller peaks and troughs than typical intramuscular dosing (The Journal of Urology, 2022).

Does SubQ testosterone cause fewer side effects than IM? 

It may. In one study, the subcutaneous route was associated with a more favorable side-effect profile than the intramuscular route, though this is limited, single-study evidence (The Journal of Urology, 2022). Individual results vary, and all routes need monitoring.

With IM vs SubQ testosterone injections, how often do you inject? 

Intramuscular dosing is usually less frequent, while subcutaneous dosing is usually more frequent. Your provider sets the schedule from your labs and your response. There is no single frequency that fits everyone.

Is SubQ testosterone as effective as IM?

Yes. A 2022 review in The Journal of Clinical Endocrinology and Metabolism found that limited evidence suggests subcutaneous dosing performs comparably to intramuscular, with easier self-administration and less discomfort. Both routes are accepted treatments for diagnosed deficiency.

Do I need a prescription and bloodwork for testosterone injections? 

Yes. Testosterone is a Schedule III controlled substance, so a prescription follows a clinical evaluation. Providers confirm low testosterone using repeat morning blood testing together with symptoms (American Urological Association, 2018).

Can I switch from IM to SubQ testosterone? 

Often yes, with provider guidance and repeat labs. Many men switch for comfort and steadier levels. The dose may be adjusted when the route changes, so follow-up testing matters.

Is compounded testosterone the same as FDA-approved testosterone? 

No. Compounded testosterone is not FDA-approved, and guidelines favor commercially manufactured products when possible (American Urological Association, 2018). Ask your provider which product you are prescribed and why.

References

• DEA. Fourth Temporary Extension of COVID-19 Telemedicine Flexibilities for Prescription of Controlled Medications. 2025.

• FDA. Class-Wide Labeling Changes for Testosterone Products. 2025.

• J Clin Endocrinol Metab. 2018;103(5):1715-1744.

• J Clin Endocrinol Metab. 2022;107(3):614-626.

• J Urol. 2018;200(2):423-432.

• J Urol. 2022;207(3):677-683.

• N Engl J Med. 2023;389(2):107-117.