How to Increase Testosterone Naturally: What the Science Actually Says

Testosterone is one of the most talked-about — and most misunderstood — hormones in men’s health. It influences muscle mass, energy, mood, libido, body composition, and motivation, and its natural decline with age is real. But between the testosterone clinics promising miracles and the supplement industry selling “boosters” with little evidence, it’s hard to know what actually works. The truth is that several genuinely effective, evidence-based lifestyle strategies can support healthy testosterone levels naturally.

According to Simply Younger’s analysis of the research on testosterone and ageing, the foundations of healthy testosterone are the same foundations of overall health: sleep, body composition, strength training, stress management, and key nutrients. This guide separates what the science actually supports from the marketing, and shows you the levers that genuinely matter.

Why Does Testosterone Decline With Age?

Testosterone levels in men peak in early adulthood and then decline gradually — on average about 1% per year after age 30. This is a natural part of ageing. However, the rate of decline varies enormously between individuals, and much of that variation comes down to lifestyle factors rather than age alone. Two men of the same age can have very different testosterone levels based on their sleep, body composition, activity, and stress.

This is the empowering part: while you can’t stop the age-related decline entirely, you have substantial influence over where your levels sit within your genetic range. Many men accelerate their own decline through poor sleep, excess body fat, inactivity, and chronic stress — all of which are modifiable. Understanding testosterone as something you can influence, rather than simply lose, is the right starting point. It connects to the broader picture of how lifestyle shapes ageing in our guide on biological age versus chronological age.

How Does Sleep Affect Testosterone?

Sleep is arguably the single most powerful lever for natural testosterone. The majority of daily testosterone release happens during sleep, particularly during deep and REM sleep. Research has shown that restricting sleep to five hours a night for just one week can significantly lower testosterone levels in healthy young men — a striking demonstration of how directly sleep affects this hormone.

For men over 40, whose sleep quality is often already declining, this makes sleep optimisation a top priority for hormonal health. Prioritising seven to nine hours of quality sleep, with good sleep hygiene, is one of the most effective things you can do for your testosterone. Our guide on sleep and longevity covers how to improve deep sleep specifically.

Why Body Composition Matters for Testosterone

Body fat and testosterone have an important relationship. Excess body fat, particularly visceral fat around the abdomen, contains an enzyme called aromatase that converts testosterone into oestrogen. This means higher body fat tends to lower testosterone, which in turn makes it harder to build muscle and easier to gain fat — a self-reinforcing cycle that works against you.

The flip side is that reducing excess body fat can help support healthier testosterone levels, reversing that cycle. This is why body composition — not just weight — is so important to track. A smart scale that measures body fat and muscle mass, like the Hume Health scale I use, gives you far more useful information than the bathroom scale, letting you see whether you’re moving toward a more favourable composition for hormonal health.

Does Strength Training Boost Testosterone?

Resistance training is one of the most effective forms of exercise for supporting testosterone. Heavy compound movements — squats, deadlifts, presses, rows — that recruit large amounts of muscle produce the most favourable hormonal response. Beyond any acute hormonal effect, strength training builds and maintains muscle mass, improves insulin sensitivity, and helps reduce body fat, all of which support healthy testosterone over time.

For men over 40, strength training is non-negotiable for both testosterone and overall healthy ageing. Building muscle requires adequate protein, and the ageing body becomes less efficient at using it — which is why I prioritise a complete essential amino acid supply through PerfectAmino alongside whole-food protein, ensuring the raw materials for muscle are always available to support my training.

Which Nutrients Support Testosterone?

Several nutrients are genuinely important for testosterone production, and deficiencies can lower levels:

• Vitamin D: functions almost like a hormone in the body and is linked to testosterone. Deficiency is extremely common, especially in men over 40. Correcting a deficiency can support healthy levels.
• Zinc: essential for testosterone production. Deficiency is associated with lower levels, and supplementation helps if you’re deficient.
• Magnesium: involved in testosterone availability and very commonly under-consumed.
• Healthy fats: testosterone is made from cholesterol, so very low-fat diets can impair production. Adequate healthy fats support hormone synthesis.

It’s worth noting that these nutrients help most when you’re correcting a deficiency — megadosing beyond sufficiency doesn’t push testosterone higher. Our guide on vitamin D3 and K2 covers the vitamin D piece in detail.

How Does Stress Lower Testosterone?

Chronic stress is a significant testosterone suppressor. The stress hormone cortisol and testosterone have an inverse relationship — when cortisol is chronically elevated, testosterone tends to be suppressed. This is part of why men under sustained high stress often experience low energy, low libido, and difficulty building muscle.

Managing chronic stress — through sleep, exercise, time in nature, breathwork, and supporting the body’s relaxation response — therefore supports healthy testosterone. Many men over 40 also use drug-free wellness tools to support their overall vitality and stress resilience; you can explore the LifeWave phototherapy range on my LifeWave Brand Partner page. Managing stress isn’t just about feeling calmer — it’s a genuine hormonal strategy.

Frequently Asked Questions

How can I increase testosterone naturally?

The most effective natural strategies are: prioritise quality sleep (most testosterone is produced during sleep), maintain a healthy body composition (excess fat lowers testosterone), do regular strength training with compound lifts, eat adequate protein and healthy fats, correct deficiencies in vitamin D, zinc, and magnesium, and manage chronic stress. These foundations have far more impact than any “testosterone booster” supplement.

Do testosterone booster supplements work?

Most commercial “testosterone boosters” have little quality evidence behind them. The nutrients that genuinely matter — vitamin D, zinc, magnesium — help mainly when you’re correcting a deficiency, not by pushing levels above normal. There’s no supplement that reliably raises testosterone in men who aren’t deficient. Your money and effort are far better spent on sleep, body composition, training, and stress management.

At what age does testosterone start to decline?

Testosterone typically peaks in early adulthood and begins a gradual decline of roughly 1% per year after around age 30. However, the rate varies widely between individuals based on lifestyle. Poor sleep, excess body fat, inactivity, and chronic stress accelerate the decline, while healthy habits help maintain levels within your genetic range. Age sets the trend, but lifestyle shapes the outcome.

Does losing weight increase testosterone?

Reducing excess body fat, particularly visceral fat, can help support healthier testosterone levels. This is because fat tissue contains aromatase, an enzyme that converts testosterone to oestrogen, so higher body fat tends to lower testosterone. Losing excess fat can reverse this, though the goal should be improving body composition (losing fat while preserving muscle) rather than just dropping weight.

Can lack of sleep lower testosterone?

Yes, significantly. Most testosterone is produced during sleep, so insufficient or poor-quality sleep directly lowers levels. Research has shown that restricting sleep to five hours a night for one week can significantly reduce testosterone in healthy men. Prioritising seven to nine hours of quality sleep is one of the most powerful natural ways to support healthy testosterone.

Should I see a doctor about low testosterone?

If you have persistent symptoms like very low energy, low libido, depressed mood, or difficulty building muscle despite good habits, it’s worth getting your levels tested by a doctor. Genuine clinical low testosterone is a medical condition that warrants professional assessment. Lifestyle strategies support healthy levels, but they aren’t a substitute for medical evaluation when symptoms are significant.

Related Reading

• Vitamin D3+K2: What Your Doctor Isn’t Telling You
• Sleep and Longevity: Why Deep Sleep Is the Most Powerful Anti-Ageing Tool
• Biological Age vs Chronological Age: How to Measure What Actually Matters

Affiliate disclosure: This post contains affiliate links including LifeWave, PerfectAmino, and Hume Health. I may earn a commission if you purchase through my links, at no additional cost to you. I only recommend products I personally use.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before making changes to your health regimen, especially regarding hormones.