Lower testosterone levels are linked to poor muscle mass, frailty, osteoporosis, paradoxically an increased prostate cancer risk, demotivation, low mood and depression often referred to as the Manopause. While a gradual decline in testosterone is a completely natural part of male aging—typically dropping by about 1% to 2% per year after age 30. Medications such as opioid painkillers, glucocorticoids (like prednisone), finasteride, and certain antidepressants or blood pressure medications can damage erectile function. Other modifiable factors have a strong influence:
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Health, lifestyle, and environmental which lower testosterone:
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Excess Body Fat: Fat cells, via an enzyme called aromatase, converts testosterone into oestrogen. The more fat to muscle ratio the less testosterone.read more
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Type 2 Diabetes or metabolic syndrome is linked to insulin resistance which interferes with the signals the brain sends to the testes to produce testosterone… read more
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Chronic Sleep Deprivation: Testosterone is mainly produced during REM and deep sleep. Insomnia, sleep apnoea, or getting <7 hours of sleep results in a lower levels.
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Heavy drinking damages the Leydig cells in the testes (which produce testosterone), forces the liver to prioritise alcohol metabolisation over hormone regulation..read more
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Nutritional Deficiencies: Diets lacking in key micronutrients—specifically essential minerals and Vitamin D—can handicap the body’s ability to synthesise testosterone..read more
- Endocrine-Disrupting Chemicals (EDCs). Common culprits that mimic oestrogen or block androgens include BPA (found in plastics), phthalates (in personal care products), and certain agricultural pesticides..read more
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Sedentary Lifestyle, particularly a lack of resistance or strength training, signals to the body that high levels of muscle-building hormones are not required. Regular heavy lifting is a naturally maintains testosterone..read more
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Chronic Stress (High Cortisol): Cortisol and testosterone share the same precursor hormones, and the body will always prioritize survival (cortisol) over reproduction and muscle building (testosterone). Therefore, more stress less testosterone..read more
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New research – Testosterone and Gut Health
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There is a fascinating and highly active link between the state of the gut microbiome and testosterone levels. There two main reasons for this:
1. The gut doesn’t just digest food—it acts very much like an endocrine (hormone-producing and regulating) organ. Within your gut is a specific subset of bacteria known collectively as the eoestrobolome. Its primary job is to help metabolise and excrete excess oestrogen from the body. When your gut is healthy, estrogen is processed by the liver, sent to the gut, and passed out as waste. However, if you have an imbalance of bad bacteria, they produce high levels of an enzyme called beta-glucuronidase. This enzyme breaks the bond the liver created, allowing estrogen to be reabsorbed back into your bloodstream. When oestrogen levels rise artificially high in a man, the brain senses this and signals the testes to slow down testosterone production to maintain what it mistakenly believes is a proper balance.
2. A compromised gut lining caused by dysbiosis allows bacterial toxins called lipopolysaccharides (LPS) to slip from the digestive tract into the bloodstream. This condition, known as metabolic endotoxemia, triggers systemic, whole-body inflammation. The Leydig cells in the testes, which are responsible for manufacturing testosterone, are highly sensitive to inflammation. When the immune system is constantly fighting off these escaped gut toxins, it produces inflammatory cytokines that directly impair the Leydig cells’ ability to synthesise testosterone.
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The UK National Longevity-testosterone Trial
This double Blind randomised Trial was published in the Journal of Ageing and Longevity in April 2026. It involved 220 men and measured impact of a dietary intervention on changes in three key biomarkers of longevity: Testosterone levels, grip strength which normally decline with age and systemic inflammation which increases.
The first element of the study found a statistically significant (8%) improvement in average grip strength following a 4-month intake of the capsule which boosted dietary levels of six phytochemical-rich foods – The YourPhyto supplement. This finding supports previous studies which linked better exercise performance after increased intake of phytochemical-rich foods via concentrates or supplements. Most of these trials, however, involved younger fitter athletes, so it is reassuring to report this benefit in an older cohort.
The second randomised element of this study demonstrated that additional intake of the 5-blend lactobacillus capsule, which aimed to improve gut health, called Yourgutplus further improved grip strength from start to finish but 57% greater than the phytochemicals alone. The importance of a healthy gut for athletes is well known and the role for probiotic supplements has, previously found to help athletes. This was the world’s first double-blind RCT to show that interventions that boosted, and combined, both phytochemical rich foods and lactobacillus probiotics helped improve strength and other markers of longevity in a non-athletic, older population. It supports, laboratory studies reporting a strong beneficial synergy between phytochemicals and probiotic bacteria .
The results showed that blood Testosterone levels, although never exceeding the safe normal range were 12% higher in the combined supplement group – a statistically significant benefit. Systemic inflammation also reduced significantly.
Although healthy diet to improve gut health should be encouraged, this evaluation did establish a role for nutritional capsules. Many nutritionist believe these supplements are a useful addition to a healthy lifestyle outside clinical studies as the specific nutrients can be enhanced, measured and standardised for consistency.
See more about the trial on Youtube: