Testosterone rarely falls on its own. The three things I look at first are oestrogen, cortisol and insulin: excess oestrogen can block testosterone production, chronic stress suppresses it through the adrenal pathway, and insulin resistance feeds the oestrogen side because fat cells are oestrogenic. Find which of those is driving yours and you have somewhere real to start.
Testosterone is not just about bedroom antics. It underpins mood, heart health, brain function, libido and overall vitality — it is the control centre a great deal of the rest of the system runs off — so when it drops, it ripples.
What does low testosterone feel like?
Rarely one dramatic thing. More often a collection that is easy to put down to age or work:
- Low energy and low mood
- Poor concentration and brain fog
- Poor sleep
- Reduced libido
- Cholesterol or blood sugar that will not come under control
- Weight gain around the chest, which is very common with oestrogen dominance
How does oestrogen block testosterone in men?
When oestrogen runs high in a man, it suppresses testosterone. Part of the excess comes from outside: xenoestrogens are oestrogen-mimicking compounds found in plastics, pesticides, heavy metals and processed meats, and they drive oestrogen levels up.
The liver is what clears the excess, and it relies on glutathione to carry it out. When the liver cannot clear the excess efficiently, oestrogen dominance can follow.
Where does stress come in?
High cortisol suppresses testosterone through the adrenal pathway, and the picture it produces — low mood, poor sleep, reduced libido, declining heart and brain health — overlaps heavily with the oestrogen one. The result looks the same. The root cause is different, and so is the fix.
Chronic stress also depletes glutathione faster than the body can replenish it, so it hits the oestrogen side as well. And sleep matters here more than people expect, because sleep deprivation raises cortisol in the same way chronic stress does.
Why is insulin part of it?
At high levels insulin is inflammatory, and the body stores fat — particularly visceral fat around the middle — to protect the vital organs from it. Fat cells are oestrogenic. So insulin resistance quietly raises oestrogen, and oestrogen suppresses testosterone.
Insulin resistance can develop silently for up to 10–15 years before it appears on standard blood tests. HbA1c on its own is not enough; fasting insulin alongside it shows how hard your body is working to manage blood sugar.
How to get tested properly
Test in the morning, at least 48 hours after any hard training. If you take a hair, skin and nail formula, pause it for 48–72 hours beforehand — high-dose biotin can cause falsely high testosterone readings. If your panel includes PSA, keep those 48 hours clear of cycling, rowing and long stretches sitting down, which can cause a temporary spike that has nothing to do with prostate health.
A male hormone panel is one of the tests we arrange through functional testing, and I would want fasting insulin, HbA1c and a lipid panel next to it rather than reading testosterone on its own.
What actually helps?
That depends on which driver is yours, but a few things come up for almost everyone:
- Zinc. Pumpkin seeds are one of the best plant sources, and zinc is essential for testosterone production.
- Muscle. Creatine helps you build and maintain muscle, and muscle mass is indicative of longevity — for men and women both, not only people who train.
- Blood sugar. Eat in order — fibre, protein, fat, then carbohydrates — leave around four hours between meals, and walk after them.
- The liver. Bone broth and cruciferous vegetables support glutathione production, and reducing plastics and processed meat reduces what it has to clear.
- Sleep, because it is the cheapest cortisol intervention there is.
Hormone and thyroid symptoms rarely travel alone. A full consultation looks at the whole picture.
Book Consultation →Who this is not for
If you are on testosterone replacement, or have been advised to consider it, that is a medical decision between you and your GP, and I do not advise for or against it. If you are trying to conceive, sperm health responds to its own three-month runway, and fertility and preconception covers that properly. Any new symptom that worries you goes to your GP first.
Common questions
Is it just my age?
It can feel that way. But oestrogen, cortisol and insulin are all things you can measure and do something about, which is not true of your birthday.
Is TRT the answer?
That is a conversation for your GP. Where you are taking it, the drivers underneath still matter — replacement does not change your stress load, your blood sugar or what your liver is having to clear.
How long before I notice a difference?
I would not put a number on it, and I would be wary of anyone who does. Sleep and blood sugar tend to be felt first because they are the fastest to change.
The bottom line
Low testosterone is usually downstream of something. Look at oestrogen, cortisol and insulin, test properly, and fix the driver rather than chasing the number.
If that reads like the last couple of years, bring it to a free 15-minute call and we will work out together whether a full consultation is the right next step.
This article shares naturopathic and lifestyle guidance for general education and isn't a substitute for personalised medical advice. Always speak to your GP before changing any prescribed medication or if you have an existing health condition.
