What is Testosterone (Intramuscular/Subcutaneous): Uses, Dosage, Side Effects and More

Testosterone injections are a hormone replacement therapy that delivers the male hormone testosterone directly into your muscle or under your skin. These injections help restore testosterone levels in men whose bodies don't produce enough of this essential hormone naturally.

If you're considering testosterone therapy or your doctor has recommended it, you likely have questions about how it works, what to expect, and whether it's right for you. Understanding this treatment can help you make informed decisions about your health and feel more confident about the process.

What is Testosterone Injection?

Testosterone injection is a synthetic version of the hormone your body naturally produces in the testicles. It comes as a clear, oily liquid that's injected either into a muscle (intramuscular) or under the skin (subcutaneous) to replace or supplement your body's testosterone production.

This medication is identical to the testosterone your body makes, just delivered from an external source. Think of it as giving your body the building blocks it needs when it can't produce enough on its own.

What is Testosterone Used For?

Testosterone injections primarily treat low testosterone levels in men, a condition called hypogonadism. Your doctor might recommend this treatment if blood tests show your testosterone levels are below normal ranges and you're experiencing related symptoms.

The most common reasons doctors prescribe testosterone injections include restoring energy levels, improving mood, maintaining muscle mass, and supporting sexual function. Some men also use it to help with bone density issues that can occur with low testosterone.

In certain cases, testosterone may be prescribed for transgender men as part of hormone therapy, though this requires specialized medical supervision and monitoring.

How Does Testosterone Work?

Testosterone is considered a moderately strong hormone that works by binding to specific receptors throughout your body. Once injected, it travels through your bloodstream and attaches to these receptors in muscles, bones, brain, and other tissues.

The hormone then triggers various processes that help maintain masculine characteristics and body functions. It supports protein synthesis for muscle building, influences mood and energy levels, and helps maintain bone density.

Intramuscular injections typically provide steady hormone levels for 1-2 weeks, while subcutaneous injections may need more frequent dosing but can offer more consistent blood levels with smaller fluctuations.

How Should I Take Testosterone?

Your healthcare provider will show you the proper injection technique, whether you're doing intramuscular or subcutaneous injections. Most people learn to self-administer these injections at home after proper training.

For intramuscular injections, common sites include the thigh muscle or upper buttock area. You'll use a longer needle to reach the muscle tissue. Subcutaneous injections go into the fatty tissue under your skin, typically in the abdomen or thigh, using a shorter needle.

Always rotate injection sites to prevent irritation or scar tissue buildup. Clean the injection site with alcohol before each injection, and never share needles or vials with others.

You don't need to take testosterone with food since it's injected directly into your body. However, staying well-hydrated and maintaining a balanced diet can help your body use the hormone more effectively.

How Long Should I Take Testosterone For?

Most men with clinically low testosterone need long-term treatment, often for years or even indefinitely. Your body doesn't "learn" to produce more testosterone from the injections, so stopping treatment typically means your levels will return to where they were before.

Your doctor will monitor your progress with regular blood tests, usually every 3-6 months initially, then less frequently once your levels stabilize. These check-ups help ensure the treatment is working effectively and safely.

Some men may need dosage adjustments over time based on their response, side effects, or changes in health status. Never stop testosterone therapy abruptly without discussing it with your healthcare provider first.

What Are the Side Effects of Testosterone?

Like any medication, testosterone injections can cause side effects, though many men tolerate them well. Understanding what to expect can help you recognize normal responses versus concerning symptoms.

Here are the most common side effects you might experience, keeping in mind that not everyone will have these reactions:

• Injection site reactions like redness, swelling, or soreness
• Mood changes, including increased irritability or mood swings
• Acne or oily skin, similar to what some experience during puberty
• Increased body hair growth
• Sleep disturbances or changes in sleep patterns
• Fluid retention causing mild swelling in hands or feet

These common effects often improve as your body adjusts to the treatment, typically within the first few months of therapy.

More serious side effects are less common but require immediate medical attention. These concerning symptoms include chest pain, difficulty breathing, severe mood changes, or signs of blood clots like leg swelling with pain.

Some men may experience increased red blood cell production, which sounds beneficial but can actually thicken the blood and increase clot risk. This is why regular blood monitoring is so important.

Long-term use may also affect prostate health, though current research shows mixed results. Your doctor will monitor your prostate through regular exams and blood tests.

Who Should Not Take Testosterone?

Testosterone isn't safe for everyone, and certain health conditions make this treatment inappropriate or risky. Your doctor will carefully review your medical history before prescribing testosterone therapy.

You should not use testosterone if you have prostate cancer or breast cancer, as testosterone can potentially fuel the growth of these hormone-sensitive cancers. Men with a history of these cancers typically need alternative treatments.

Other conditions that may prevent testosterone use include:

• Severe heart disease or recent heart attack
• Untreated sleep apnea
• Severe liver disease
• High red blood cell counts (polycythemia)
• Uncontrolled high blood pressure
• History of blood clots

Men trying to father children should also discuss alternatives, as testosterone can suppress sperm production and reduce fertility.

Testosterone Brand Names

Several brand names are available for testosterone injections, each with slightly different formulations or concentration strengths. Common brands include Depo-Testosterone, Testosterone Cypionate, and Testosterone Enanthate.

These different formulations mainly vary in how long they last in your body and how often you need injections. Your doctor will choose the best option based on your specific needs, insurance coverage, and how well you respond to treatment.

Generic versions are also available and work just as effectively as brand-name options, often at a lower cost.

Testosterone Alternatives

If injections aren't right for you, several other testosterone delivery methods exist. Topical gels and patches applied to the skin provide daily hormone absorption, though they require consistent application and have transfer risks to family members.

Testosterone pellets can be implanted under the skin every 3-6 months, providing steady hormone levels without frequent dosing. Some men prefer this option for its convenience, though it requires a minor surgical procedure.

Nasal gels and oral medications are newer options, though they may not be as effective as injections for severely low testosterone levels.

Is Testosterone Better Than Clomiphene?

Clomiphene works differently than testosterone by stimulating your body to produce more of its own testosterone, rather than replacing it directly. This makes it a good first-line treatment for younger men or those hoping to maintain fertility.

Testosterone injections tend to be more effective for severely low testosterone levels and provide more predictable results. However, they suppress your body's natural testosterone production, which can affect fertility and testicular size.

Clomiphene may work better for men whose testosterone production is only mildly impaired, while testosterone injections are typically better for those with more significant hormone deficiencies. Your doctor can help determine which approach fits your specific situation.