After 40, testosterone levels in men decline by roughly 1–2% every year. That might not sound dramatic, but the cumulative effect on energy, mood, body composition, and sexual health can be significant — and most men never connect the dots.

Why Testosterone Drops After 40

The primary driver is a natural slowdown in the testes’ Leydig cells, which are responsible for testosterone synthesis. At the same time, sex hormone-binding globulin (SHBG) levels rise with age, binding to available testosterone and leaving less of the “free” form that the body can actually use. Chronic stress, poor sleep, excess body fat, and a sedentary lifestyle accelerate this process considerably.

Recognising the Signs

Low testosterone rarely announces itself clearly. Instead, it tends to arrive quietly through a cluster of symptoms that are easy to attribute to “just getting older.” Key signs include:

Getting Tested: What the Numbers Mean

A simple blood test measuring total testosterone — and ideally free testosterone and SHBG — gives the clearest picture. Most labs consider the normal range to be 300–1,000 ng/dL for adult men, but many specialists argue that symptoms matter as much as numbers. A man at 400 ng/dL with significant symptoms may benefit from intervention just as much as one testing at 250 ng/dL.

Lifestyle Changes That Move the Needle

Before considering medical treatment, several evidence-backed lifestyle strategies can naturally raise testosterone levels:

• Resistance training — compound lifts like squats and deadlifts trigger the greatest testosterone response
• Sleep optimisation — most testosterone is produced during deep sleep; aim for 7–9 hours
• Reducing body fat — adipose tissue converts testosterone to oestrogen via aromatase
• Zinc and vitamin D — both are directly involved in testosterone synthesis and are commonly deficient
• Stress reduction — cortisol actively suppresses testosterone; chronic stress is particularly damaging

When Medical Support Makes Sense

For men with confirmed low testosterone and persistent symptoms despite lifestyle changes, testosterone replacement therapy (TRT) and related treatments deserve serious consideration. At Basra Refs Health, we also explore how focused shockwave therapy for erectile dysfunction can address the vascular side of low testosterone’s effects on sexual function without relying solely on hormones.

Men experiencing both hormonal and sexual performance concerns may also want to read our guide on testosterone and sexual performance for a fuller picture of how these systems interact.