Testosterone Subcutaneous Injection: How to Do It by Yourself

Last updated: June 9, 2026

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In a previous article, I showed you how to perform a testosterone injection into the muscle (intramuscular, IM). Today, I want to introduce you to a gentler, easier alternative that has been gaining popularity worldwide: the subcutaneous (SC) testosterone injection — injecting into the fat layer just under the skin rather than deep into the muscle.

Many of my patients on testosterone replacement therapy find the traditional IM injection uncomfortable, and some need a family member to help them reach the buttock or thigh muscle. The good news is that modern research shows the subcutaneous route is just as effective — and usually far more comfortable and easier to self-administer.

Why Consider the Subcutaneous Route?

For almost 8 decades, intramuscular (IM) testosterone injections have been the standard. They are inexpensive and produce predictable testosterone levels — but they are difficult to self-administer and are often associated with discomfort. Recently, the subcutaneous (SC) route has gained popularity because self-administration is much easier, and the available evidence supports its feasibility.

The key advantages of the SC route include:

• Easier self-injection: No need to reach deep muscle or ask for help.
• Less pain: Smaller needles and a shallower injection make it virtually painless for most men.
• No risk of sciatic nerve injury: A known (though rare) risk with buttock IM injections.
• Stable hormone levels: SC injection produces smoother, more stable testosterone levels with smaller peaks and troughs.
• Better adherence: Because it is convenient and comfortable, patients are more likely to stay on therapy long-term.

A landmark 52-week clinical trial published in The Journal of Urology found that a weekly subcutaneous testosterone enanthate auto-injector produced steady testosterone levels with small fluctuations, and that more than 95% of patients reported no injection-related pain. The authors concluded that the SC route is a safe, well-tolerated, and virtually painless option (Kaminetsky et al., J Urol 2019).

IM vs SC: What’s the Difference?

Feature	Intramuscular (IM)	Subcutaneous (SC)
Injection depth	Deep into the muscle	Into the fat layer under the skin
Common site	Buttock or outer thigh	Abdomen (belly) or thigh
Needle size	Longer, larger gauge	Shorter, smaller gauge (23-25G)
Pain level	Moderate discomfort	Minimal — virtually painless
Self-administration	Difficult; may need help	Easy to do alone
Testosterone levels	Larger peaks and troughs	Smoother, more stable

Things You Need to Prepare

• Alcohol swabs
• Your prescribed testosterone vial (e.g., testosterone enanthate or cypionate) — always check the expiry date
• A 1 mL Luer-Lok syringe (preferred to prevent the needle from disengaging due to the oil’s viscosity)
• A drawing-up needle (18-21G) to draw the testosterone from the vial
• A fine short injection needle (23-25 gauge, 5/8-inch) for the subcutaneous injection
• A sharps disposal container

Where to Inject: The Landmark

The two recommended sites for subcutaneous testosterone injection are:

• The abdomen (belly): Inject into the fatty tissue 3 to 5 cm to the side of the belly button (umbilicus). Avoid the area too close to the navel.
• The thigh: The fatty tissue of the front or outer thigh is also a suitable site.

Gently pinch a fold of skin and fat to lift it away from the muscle. This helps ensure the injection goes into the subcutaneous layer and not the muscle.

Step-by-Step: How to Do a Subcutaneous Testosterone Injection

⚠️ Important: Do NOT attempt your first injection by yourself. You must be trained and supervised by a medical professional until you are fully competent.

1. Wash your hands thoroughly and sit in a comfortable chair with your supplies ready.
2. Decide on your injection site (abdomen 3-5 cm beside the navel, or thigh). Alternate sites with each injection.
3. Draw the prescribed testosterone dose from the vial using the larger drawing-up needle (18-21G) on your Luer-Lok syringe.
4. Remove all air bubbles from the syringe (air must not be injected).
5. Replace the drawing-up needle with the fine injection needle (23-25G).
6. Clean the injection site with an alcohol swab and let it air-dry.
7. Gently pinch a fold of skin and insert the needle at a 45 to 90-degree angle into the fatty tissue.
8. Slowly inject the testosterone over several seconds.
9. Remove the needle and gently press the site with a clean cotton ball or gauze. Do not rub.
10. Dispose of the needle and syringe safely in your sharps container.

Note: For the ultralong-acting ester testosterone undecanoate (a larger volume), the injection should be given more slowly over 2-3 minutes. Discuss the correct technique with your urologist, as this formulation has specific considerations.

Recommended Dose

Based on clinical studies, a common starting dose for subcutaneous testosterone enanthate or cypionate is 75 mg once weekly. This slightly lower weekly dose is usually sufficient to achieve healthy testosterone levels. Your doctor may adjust the dose down to 50 mg or up to 100 mg per week based on your blood test results. On-treatment testosterone should be measured midway between injections, and monitoring should continue periodically.

Possible Side Effects

Local reactions are usually mild and temporary, and may include:

• Minor redness, itching, or a small painless lump at the injection site
• Light bruising or bleeding

Because testosterone levels achieved via SC are similar to IM, the general systemic effects of testosterone therapy still apply and require monitoring — including a possible rise in red blood cell count (hematocrit), blood pressure, and PSA. This is why regular follow-up with your urologist is essential.

If you would like to discuss whether subcutaneous testosterone therapy is right for you, or to be trained in proper self-injection technique, Dr. Soarawee Weerasopone offers consultations at Bangkok Hospital Headquarters. Book a consultation here.

Frequently Asked Questions

Is subcutaneous testosterone injection as effective as intramuscular?

Yes. Multiple studies show that subcutaneous (SC) injection of testosterone enanthate or cypionate produces serum testosterone levels comparable to the intramuscular (IM) route. In fact, SC injection often produces smoother, more stable hormone levels with smaller peaks and troughs, while being easier to self-administer and less painful.

Where do I inject subcutaneous testosterone?

The two recommended sites are the abdomen — 3 to 5 cm to the side of the belly button — and the fatty tissue of the thigh. Gently pinch a fold of skin and fat, then insert the fine needle at a 45 to 90-degree angle. Always rotate injection sites to avoid irritation.

What size needle should I use for subcutaneous testosterone?

Clinical studies typically use a 1 mL Luer-Lok syringe with a fine 23 to 25-gauge, 5/8-inch needle for the injection itself, and a larger 18 to 21-gauge needle to draw the oil-based testosterone from the vial. A Luer-Lok syringe is preferred because the oil’s viscosity can otherwise cause the needle to detach.

Is subcutaneous testosterone injection painful?

For most men, no. In a 52-week clinical trial, more than 95% of patients reported no injection-related pain with weekly subcutaneous testosterone. The smaller needle and shallower injection make it virtually painless compared with the traditional intramuscular route.

Can I switch from intramuscular to subcutaneous injections?

Often, yes. Many patients successfully switch from IM to SC injection while maintaining stable testosterone levels. Studies in patients who switched routes found no significant change in hormone levels, and most preferred not to return to IM injection. Always make this change under the guidance of your urologist.

Disclaimer: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any medical treatment.