How to inject testosterone depends on the exact product on your prescription. Depo-Testosterone is labeled for intramuscular injection in the gluteal muscle. Xyosted is labeled for subcutaneous injection in the abdomen. Each product also has its own dose schedule and areas to avoid.1,2 Neither label specifies needle depth, gauge, angle, or skin-pinch technique. Your prescriber should demonstrate those details before your first injection.
Product Rules for How to Inject Testosterone
Intramuscular injection delivers medication into muscle. The FDA prescribing information for Depo-Testosterone states that the product "is for intramuscular use only" and that injections "should be given deep in the gluteal muscle." The label also says Depo-Testosterone should not be given intravenously.1
Subcutaneous injection delivers medication beneath the skin. The FDA prescribing information for Xyosted states that Xyosted "is for subcutaneous injection in the abdominal region only." It also says to avoid intramuscular and intravascular administration.2
Xyosted uses the left or right side of the abdomen. Its label excludes the area within two inches of the navel.2 Neither label provides instructions for a thigh injection. If your prescription differs from these products, your clinician should identify the approved site from its instructions for use.
The testosterone cypionate guide covers the drug in more detail. The broader hormone replacement therapy guide explains the available delivery types.
Labeled Testosterone Injection Dose Schedules
A testosterone injection dosage chart only makes sense when it names the product. Depo-Testosterone and Xyosted carry different labeled schedules.
| Product | Labeled Route and Site | Labeled Replacement Schedule |
|---|---|---|
| Depo-Testosterone | Intramuscular, deep in the gluteal muscle | 50 to 400 mg every two to four weeks for replacement in hypogonadal men1 |
| Xyosted | Subcutaneous, left or right side of the abdomen | Starting dose of 75 mg once weekly2 |
These figures describe the prescribing information. They are not instructions for choosing your own dose. Your prescriber sets the dose and interval, then uses repeat labs and your response to decide whether the prescription needs adjustment.
Both labels classify testosterone as a Schedule III controlled substance.1,2 A separate comparison covers testosterone injections versus creams.
Evidence From Weekly Subcutaneous Testosterone
One 52-week, single-arm, open-label study evaluated weekly subcutaneous testosterone enanthate delivered through an auto-injector. The study enrolled 150 patients who began with the labeled 75 mg weekly dose.3
At week 12, 92.7% achieved the study's average total testosterone window of 300 to 1,100 ng/dL. That range was the study's primary endpoint window. It is not a universal treatment target. More than 95% of participants reported no injection-related pain.3
The most frequently reported treatment-emergent events were increased hematocrit, hypertension, and increased prostate-specific antigen (PSA). These events led to discontinuation in 30 men. The study reported no study drug-related serious adverse events.3
This study did not compare subcutaneous injections with intramuscular injections. It supports the labeled use of one subcutaneous product without establishing that one route performs better for every person.
The current Xyosted label records that its boxed warning for blood-pressure increases was removed in March 2025.2 The registration study still reported hypertension among its most frequent treatment-emergent events.3 Your prescriber can interpret the current label alongside your follow-up measurements.
Expected Timing of Testosterone Effects
Testosterone effects appear on different timelines, and the preparation can affect when changes occur. A review of published studies reported that sexual interest can begin changing after three weeks and plateau around six weeks. Changes in erections and ejaculations may take up to six months.4
The same review reported changes in quality of life within three to four weeks. Changes in fat mass, lean mass, and muscle strength appeared within 12 to 16 weeks and stabilized over six to 12 months.4
These intervals describe patterns across published studies. They do not predict when one person will notice a change. A lack of immediate results should be assessed against your preparation, prescribed schedule, symptoms, and repeat labs before your clinician considers an adjustment.
Preparation and Monitoring Around Testosterone Injections
Testosterone treatment begins with a confirmed diagnosis. The Endocrine Society clinical practice guideline recommends diagnosing hypogonadism when symptoms are present with unequivocally and consistently low testosterone. It recommends an initial fasting morning total testosterone measurement and confirmation with a repeated fasting morning measurement.5
Treatment also requires a monitoring plan. The guideline recommends discussing the benefits, risks, and monitoring of testosterone therapy with the person receiving treatment.5 The TRT overview explains how testosterone replacement therapy fits into a broader treatment plan.
Before your first self-injection, your care plan should identify:
- The exact testosterone product and prescribed dose
- The route and product-specific injection region
- The manufacturer's instructions for use
- A clinician demonstration of the prescribed technique
- A disposal plan for the used device and supplies
- The date of your next lab review
The product labels cited here do not give a universal needle gauge, length, angle, skin-pinch method, or insertion depth. Your clinician and the instructions supplied with your prescription should provide those details.
Monitoring should follow the pattern across your labs. The subcutaneous study reported increased hematocrit and PSA among its most frequent treatment-emergent events.3 Our separate guide covers hematocrit during TRT.
Once the protocol is running, the published TRT timeline sets out when each effect has been observed. Getting the prescription is a separate question from giving the injection. Online TRT clinics and the federal prescribing rules covers what the law requires first.
The Opt Take on Testosterone Injections
A physician should interpret your labs against your symptoms, choose the appropriate product, and adjust the plan as your results change. The injection route follows the prescription. Repeat testing shows whether the treatment is producing the intended laboratory response.
Opt Health begins with more than 55 biomarkers and a one-on-one physician review. Labs and physician consultations repeat every three to four months, which allows the plan to change based on your measurements. You can review the full process on the How Opt Health Works page.
One testosterone value provides limited context. Testosterone, hematocrit, PSA, symptoms, and treatment history create a fuller pattern for your physician to interpret.
Get started: Begin with Opt Health, where a physician reads your labs, builds your plan, and adjusts it over the loop.
Frequently Asked Questions
The prescribed product determines the injection site. Depo-Testosterone should be injected intramuscularly, deep in the gluteal muscle. Xyosted should be injected subcutaneously into the left or right side of the abdomen, outside the two-inch area around the navel.1,2
Neither route is universally better based on the cited evidence. Depo-Testosterone is labeled for intramuscular use, while Xyosted is labeled for subcutaneous use.1,2 The 52-week Xyosted study did not compare the two routes directly.3 Use the route specified for your prescribed product.
Depo-Testosterone should not be given intravenously. Xyosted should not be injected intramuscularly or intravascularly, and its label excludes the area within two inches of the navel.1,2 The labels cited here do not provide thigh instructions.
The cited labels do not specify a skin-pinch technique. The answer depends on the prescribed product and its instructions for use. Your clinician should demonstrate the technique that applies to your prescription before your first injection.
A first injection should begin with the exact product, route, site region, and prescribed dose in writing. You should also receive the manufacturer's instructions for use, a clinician demonstration, a disposal plan, and a follow-up lab date. A generic online technique cannot replace product-specific training.
Neither cited label provides a universal needle depth, gauge, length, or insertion angle. Depo-Testosterone says the injection should be deep in the gluteal muscle, but it does not define a numerical depth.1 Bring your prescribed product and its instructions for use to your clinician for a technique demonstration before deciding how to inject testosterone.
References
- DailyMed. DEPO-TESTOSTERONE (testosterone cypionate) injection, solution prescribing information. Accessed September 8, 2026.
- DailyMed. XYOSTED (testosterone enanthate) injection prescribing information. Accessed September 8, 2026.
- Kaminetsky JC, McCullough A, Hwang K, Jaffe JS, et al. A 52-week study of dose adjusted subcutaneous testosterone enanthate in oil self-administered via disposable auto-injector. J Urol. 2019;201(3):587-594. https://pubmed.ncbi.nlm.nih.gov/30296416/
- Saad F, Aversa A, Isidori AM, Zafalon L, et al. Onset of effects of testosterone treatment and time span until maximum effects are achieved. Eur J Endocrinol. 2011;165(5):675-685. https://pubmed.ncbi.nlm.nih.gov/21753068/
- Bhasin S, Brito JP, Cunningham GR, Hayes FJ, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. https://pubmed.ncbi.nlm.nih.gov/29562364/
This content is for informational purposes and does not replace evaluation, diagnosis, or treatment by a qualified medical professional.
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