Health Guide April 13, 2026 6 min read

Low Testosterone: Signs, Symptoms, and What to Do About It

Low testosterone affects an estimated 2-4 million men in the United States, yet the majority go undiagnosed for years. If you've been feeling tired, irritable, or just not like yourself, low T could be the reason — and it's very treatable.

What is Testosterone and Why Does it Matter?

Testosterone is the primary male sex hormone, produced mainly in the testes. It plays a critical role in muscle mass, bone density, fat distribution, red blood cell production, sex drive, mood, and cognitive function.

Testosterone levels naturally peak in your early 20s and decline about 1-2% per year after age 30. While this gradual decline is normal, some men experience a more significant drop — a condition called hypogonadism or low testosterone (low T).

Signs and Symptoms of Low Testosterone

Low T manifests differently in every man, but the most common symptoms include:

Physical Symptoms

Sexual Symptoms

Psychological Symptoms

Many men with low testosterone are told their symptoms are "just stress" or "part of getting older." If you have 3 or more of these symptoms, it's worth getting your levels tested.

What Are Normal Testosterone Levels?

Total testosterone is measured in nanograms per deciliter (ng/dL). General reference ranges:

Importantly, symptoms matter as much as numbers. Some men feel terrible at 350 ng/dL while others feel fine. Your provider will consider both your lab values and your symptoms.

What Causes Low Testosterone?

Low T can be caused by:

How is Low Testosterone Treated?

Testosterone Replacement Therapy (TRT) is the primary treatment for clinically diagnosed low testosterone. Options include:

Most men on TRT report significant improvements in energy, libido, body composition, and mood within 4-8 weeks. Full benefits typically take 3-6 months.

Getting Tested and Starting TRT Online

A simple blood test measuring your total and free testosterone levels is all it takes to confirm a diagnosis. Zera Health providers can order labs or review recent bloodwork during your online consultation.

Think you might have low testosterone?

Get a confidential evaluation from a licensed Zera Health provider. No insurance required.

Start Your Assessment
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a licensed healthcare provider before starting any treatment. Zera Health providers are independent licensed physicians who make prescribing decisions based on individual patient evaluations.