Low testosterone in men: signs, testing and what actually helps
If you’ve been feeling flat — tired by mid-afternoon, less interested in sex, slower to recover from workouts — you’ve probably wondered whether it’s your testosterone. Sometimes it is. Sometimes it’s sleep, stress, or something else entirely. The good news: you don’t have to guess. Here’s how low testosterone actually shows up, how it should be tested, and what treatment looks like.
What testosterone does
Testosterone is the main male sex hormone, but it does far more than drive libido. It supports energy, muscle and bone strength, red blood cell production, mood and focus. Levels naturally drift down with age, but some men drop low enough — at any age — that it starts to affect daily life.
Common signs of low testosterone
- Low sex drive, or erections that aren’t what they used to be
- Fatigue that sleep doesn’t fix
- Losing muscle or strength, gaining belly fat
- Low mood, irritability or trouble concentrating
- Fewer morning erections
- Reduced body or facial hair growth
Here’s the catch: every one of these can have other causes — poor sleep, sleep apnea, stress, depression, thyroid problems, alcohol or certain medications. That’s exactly why symptoms alone aren’t enough to diagnose low T.
How low testosterone should be tested
A proper diagnosis needs two things together: symptoms and blood work that confirms it. Testosterone runs highest in the morning and varies day to day, so one random test can mislead you. The American Urological Association uses a total testosterone below 300 ng/dL, confirmed on at least two separate early-morning blood tests.
A good workup usually also looks at:
- Free testosterone and SHBG (the protein that binds testosterone)
- LH and FSH, to see whether the cause is in the testes or the pituitary
- A complete blood count (CBC) and, depending on age, PSA
- Thyroid, blood sugar and other labs if your symptoms point that way
If a clinic offers you testosterone after a single afternoon test — or none at all — that’s a red flag.
Treatment options
Lifestyle first, always. Sleep, strength training, a healthy weight and less alcohol can raise testosterone on their own and make any treatment work better.
Testosterone replacement therapy (TRT). For men with confirmed low levels and symptoms, TRT can improve libido, energy, mood and body composition. It comes as injections, gels or other forms, and the right one depends on your lifestyle and labs.
If you want children soon, tell your provider. Testosterone therapy can lower sperm production and affect fertility. There are other ways to raise your body’s own testosterone that protect fertility, so this conversation matters before you start.
Is TRT safe?
For the right patient, with proper monitoring, TRT is a well-studied treatment. In 2025 the FDA updated testosterone labels after a large trial (TRAVERSE) found no increase in heart attacks or strokes in men treated for low testosterone. Labels now include a blood pressure warning, because testosterone can raise blood pressure. That’s why ongoing care matters: regular check-ins and labs (including red blood cell levels) keep treatment safe and on track.
How Invidia can help
At Invidia, men’s health visits happen by private video with Sarah Murray, FNP-C. We review your symptoms, order the right labs at a lab near you, explain your results in plain language, and build a plan — lifestyle, TRT or another option — with follow-up built in. Care is available in Arizona, Colorado, Hawaii, Idaho, Kansas, Massachusetts, Nevada, New Mexico, Oregon, Utah and Washington.
Ready to find out what’s going on? Book a men’s health visit or take the 2-minute quiz.
This article is for education only and isn’t medical advice. Talk with your provider about your own health.
This article is for general education and isn’t medical advice. Everyone is different — talk with your provider about your own symptoms and treatment options. If you have a medical emergency, call 911.
