What Is Testosterone and What Does It Do?

Testosterone is one of the androgenic hormones your body naturally produces, mainly in the testes.

Testosterone supports many of the things men tend to take for granted when levels are healthy, including:

• Energy and stamina

• Sex drive and sexual function

• Muscle strength and muscle mass

• Fat metabolism

• Bone health

• Mood, motivation, and mental clarity

When men’s levels drop too low, these areas can be affected over time. Often, it’s a combination of small changes that start to add up.

Average Testosterone Levels by Age (Total Testosterone)

Testosterone is typically measured in nanograms per deciliter (ng/dL). Most labs list a broad “normal” range (often ~300–1,000 ng/dL), but that range doesn’t account for age or symptoms, which is where confusion happens.

Men in Their 20s

• Average range: ~600–900 ng/dL

• Low T in your 20s: generally below ~400 ng/dL

A healthy man in his 20s is usually near the higher end of the range. Levels consistently under ~400 ng/dL at this age are often considered abnormally low and worth investigating, especially if symptoms are present.

Men in Their 30s

• Average range: ~500–800 ng/dL

• Low T in your 30s: generally below ~350–400 ng/dL

Testosterone typically begins a slow decline in the 30s. Many men still feel fine, but levels below ~350–400 ng/dL may be considered low for this age group, particularly with symptoms.

Men in Their 40s

• Average range: ~450–700 ng/dL

• Low T in your 40s: generally below ~300–350 ng/dL

This is the decade where symptoms often become noticeable. Levels in the low 300s may technically fall within a lab’s “normal” range, but they can still be low relative to age and how a man feels.

Men in Their 50s

• Average range: ~400–650 ng/dL

• Low T in your 50s: generally below ~300 ng/dL

By the 50s, a gradual decline is expected. Many providers consider levels under ~300 ng/dL low, especially if energy, strength, libido, or mood have changed.

Men in Their 60s and Beyond

• Average range: ~350–600 ng/dL

• Low T in your 60s+: often below ~250–300 ng/dL

Some men feel well with lower levels later in life, while others experience significant symptoms. This is where symptoms and overall health matter more than a single number.

What Is Considered Low Testosterone?

Low testosterone happens when a man’s levels fall below what’s healthy for his age and body. Clinically, this level is usually 350-300 ng/dL for a man aged 35 – 65.

Many men live with this condition longer than they should because the changes happen slowly. You might not wake up one day feeling “off.” Instead, things just don’t feel the same as they used to. This is why testing is always a good idea.

What Causes Low Testosterone?

Hormone decline is a normal part of aging, but when other factors come into play, a chain reaction can be set off, and levels can drop faster and farther than they would naturally.

Common causes include:

• Weight gain or metabolic conditions like diabetes

• Chronic illness or inflammation

• Certain medications, including steroids like corticosteroids

• Poor sleep or sleep disorders like sleep apnea

• Injury or trauma to the testes

• Hormone signaling issues involving the brain

That’s why testing by certified providers matters. Knowing why your levels are low helps determine whether treatment makes sense and how to approach it in a way that works for you.

Myths and Misunderstandings About Testosterone

There’s no shortage of misinformation about testosterone. Let’s clear up a few of the most common questions.

Does Masturbation Cause Low Testosterone?

No. Masturbation does not cause low testosterone.

Testosterone levels naturally rise and fall throughout the day. Long-term testosterone levels are influenced far more by age, health, sleep, weight, and hormones than by sexual activity.

Is Testosterone a Steroid?

No. Testosterone isn’t a steroid in the way anabolic steroids are usually talked about.

Testosterone is a hormone your body already makes. Anabolic steroids are synthetic drugs often misused at very high doses. Medically supervised testosterone therapy is about restoring levels to a healthy range, not pushing the body beyond what’s normal.

Do Receipts Lower Testosterone?

It’s an interesting question, but as far as modern science knows, probably not. Everyday contact with receipts hasn’t been shown to lower testosterone levels in a meaningful way.

Some receipts contain chemicals like BPA or BPS, which get a lot of attention online. In real life, factors like weight, sleep, stress, and chronic health conditions have a much bigger impact on testosterone levels.

Does Nicotine Boost Testosterone?

No. Nicotine isn’t a safe or effective way to support testosterone.

While small studies sometimes show short-term hormone changes, nicotine use is linked to heart disease, reduced blood flow, and erectile dysfunction. Any temporary effect isn’t worth the long-term risks.

How Do I Find Out If I Have Low Testosterone?

Low testosterone can’t be diagnosed based on symptoms alone. A blood test is needed to measure hormone levels and look at overall health.

At SynergenX and Low T Center locations, testing is fast and easy, but takes your entire medical profile into account to make sure your treatment works for your entire body, not just your hormones.

As Low T Center provider Michael Seay, NP-C, explains:

“Low testosterone isn’t just about a number on a lab report. It’s about how those levels are affecting someone’s energy, health, and quality of life. Testing helps us decide whether treatment is actually the right step.”

What Are Symptoms of Low T?

Low testosterone can be linked to symptoms like fatigue, lower sex drive, changes in body composition, and mood shifts. Because symptoms vary from person to person, they’re best evaluated alongside lab results.

For a deeper look at how symptoms manifest, read our full guide to low testosterone symptoms.

Getting Treated for Low Testosterone

If you’ve been wondering whether low t could be playing a role in how you’re feeling, testing is a straightforward place to start. There’s no obligation to begin treatment, and at Low T Center, testing is often free.