Testosterone is an essential hormone within the body, especially when it comes to building muscle, strength, and overall health. It aids in muscle growth, fat reduction, mood enhancement, and sexual well-being.

But once testosterone levels drop, via ageing or disease, many people start to think about testosterone replacement therapy (TRT) so that they can experience those benefits once more.

One of the most common questions asked is: Which type of testosterone is best for muscle growth? The answer depends on your goals, lifestyle, and how your body responds to treatment. In this article, we’ll break down the different types of testosterone used for muscle growth, the research behind it, and how to choose the right one for you.

What Is Testosterone and Why Does It Matter?

Testosterone is a hormone that is produced mainly in the testicles in men (and in lesser amounts in the ovaries in women). It’s what provides the low-pitched voice, facial hair, and muscle development in men.

But it’s not just for looks. Testosterone helps develop and maintain muscle mass, promotes fat loss, boosts energy, and improves sex drive and sex performance.

As we age, quite naturally, our testosterone levels go down. Low testosterone can lead to lower energy, muscle loss, low sex drive, and even mood swings. This is where TRT comes in to bring levels back to within the normal range.

What Is Testosterone Replacement Therapy (TRT)?

TRT is also a medical method of treatment to boost testosterone in men with low T. It comes in different forms like injections, gels, creams, patches, or pellets. It has the potential to enhance mood, energy, libido, and of course, muscle gain.

All testosterones are not made equal, though. Some are better than others when your goal is to gain muscle and boost strength.

Types of Testosterone for Muscle Growth

Let’s observe the most popular types of testosterone utilized in TRT and how they compare to muscle gain:

1. Testosterone Cypionate

• Ideal for: Building muscles, use over a long period

• Half-life: About 8 days

• Dosage: Bi-weekly or weekly injections

Testosterone cypionate is likely the most popular and recognized form of testosterone. It’s taken regularly in the U.S. for TRT. It’s long-acting, so you don’t need to take it every day. You’ll usually do fine with once weekly.

Experiments show that 100–125 mg/week doses are great for getting below-normal testosterone levels back to normal. If gaining muscle bulk is your aim, even more doses like 300–600 mg/week (under medical supervision) can increase muscle bulk, strength, and reduce body fat. This is the dose bodybuilders often speak about, but medical supervision is necessary.

2. Testosterone Enanthate

• Good for: Bodybuilders and athletes

• Half-life: 4–5 days

• Dosage: Biweekly or weekly injections

Testosterone enanthate is similar to cypionate. It’s a long-acting injection and functions almost exactly the same. The largest difference is that it is removed from your system at a much faster rate. Because it has a lower half-life, some choose to inject it two times per week so hormone levels are kept constant.

It’s also favored by those who wish to bulk, and the studies confirm its muscle and strength-building abilities.

3. Testosterone Propionate

• Optimal for: Quick cycles, speedy results

• Half-life: Around 2–3 days

• Dosage: Alternate-day injections

This type of testosterone is quicker in action and earlier out of the system. The effects are experienced by some people prior to other testosterone types. But since it lasts only a short time, it requires more frequent injections every other day or so.

It’s used more frequently by bodybuilders or athletes looking for quick increases in short cycles. It’s less convenient, however, with more dosing and risk of greater injection site irritation.

4. Testosterone Gel and Creams

• Best for: Needle-phobic users or novices

• Use: Daily (on the skin)

• Muscle building potential: Moderate

Testosterone creams and gels are easy to apply and do not require needles. You rub them on your skin, usually your shoulders or arms, every day. They’re great for people who abhor shots but will provide lower levels of testosterone.

They won’t be the best choice if gaining muscle mass as fast as possible is most important. You’ll have steady amounts of testosterone over time but not the spikes with injections.

5. Testosterone Pellets (Testopel)

• Best for: Long-term TRT

• Use: Inserted under the skin

• Duration: 3–6 months

Pellets are tiny cylinders inserted under the skin that release testosterone gradually. You don’t have to fret about daily or weekly dosing, just get them replaced every few months. But they’re not ideal for those who want accurate dosing or are new to TRT.

For muscle-building, they get their job done, but they’re less versatile for customizing your dosage according to your needs for fitness.

What the Science Says: The 2001 Bhasin Study

One of the most frequently cited studies by Dr. Bhasin and others in 2001 explored how different doses of testosterone impacted muscle mass, strength, and body fat among young men. Testosterone cypionate was given through weekly injections with dosages ranging from 25 mg to 600 mg.

Here’s what they found:

• 100–125 mg/week: Adequate to maintain or slightly boost muscle and reduce fat.

• 300–600 mg/week: Significant strength and muscle gains. Also noted was the reduction in body fat.

• Less than 50 mg/week: Minimal effect. Some actually gained fat.

The study also found that testosterone elevates free testosterone levels, lowers SHBG (sex hormone-binding globulin), and increases strength even in those who weren’t exercising.

So for building muscle, testosterone cypionate or enanthate in a dose of approximately 100–600 mg/week (depending upon your requirements) seems to be the sweet spot.

Side Effects and Safety

While testosterone can also be used to build muscle, it’s not without risk. Side effects of testosterone treatment can be:

• Acne or oily skin

• Increased red blood cells (which can raise blood pressure or clot risk)

• Reduced HDL (“good”) cholesterol

• Testicular shrinking or reduced sperm count

• Mood change

That’s why it’s so important to work with a doctor. You’ll need regular blood tests to check hormone levels, cholesterol, and red blood cell counts.

If your goal is maximum muscle growth, testosterone cypionate or enanthate is likely your best bet, especially in the 100–600 mg/week range, depending on your current levels and goals. Always start at the lower end and go up only if needed, and always under a doctor’s supervision.

While testosterone is a powerful muscle-building agent, it’s not a magic pill. You’ll still require a solid workout routine, lots of protein in your diet, and good sleep. View testosterone as an aid, not a replacement, for hard work.

Pro Tip:

Have your levels checked, sit down with a licensed physician, and establish goals before starting any testosterone therapy. Tailored treatment will always be the key to long-term success.