Hormones and metabolic health
Low Testosterone and Type 2 Diabetes: The Two-Way Link
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed July 2026
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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Low testosterone and type 2 diabetes are strongly linked and the link runs both ways. Studies find roughly a third to a half of men with type 2 diabetes have low testosterone, and low testosterone also predicts a higher future risk of diabetes. Symptoms overlap, so a blood test measuring testosterone, SHBG, LH and FSH is the honest way to tell them apart.
Tiredness, low drive, weight around the middle, poor erections. Every one of these can come from low testosterone. Every one can also come from type 2 diabetes. The two conditions share symptoms because they share biology, and one quietly feeds the other.
As of July 2026, UK guidance still does not test testosterone routinely in men with diabetes. That leaves a lot of men blaming age or stress for something measurable. This guide explains the link, how common it is, and which numbers actually tell you what is going on.
How are low testosterone and diabetes linked?
The link is a two-way street. Men with type 2 diabetes are far more likely to have low testosterone than men without it. And men with low testosterone are more likely to go on to develop type 2 diabetes. Each one raises the odds of the other.
The common thread is insulin resistance, where the body stops responding well to insulin. It sits at the heart of type 2 diabetes, and it also disrupts the hormonal signals that keep testosterone up. Extra body fat and low-grade inflammation push both problems along together.
How common is low testosterone in men with diabetes?
It is common enough that many doctors treat it as expected. Across multiple studies, somewhere between a third and a half of men with type 2 diabetes have low testosterone. That is far above the rate in men of the same age without diabetes.
The overlap shows up most clearly in the bedroom. Erectile problems are one of the earliest and most reliable flags, which is why guideline bodies now push for testosterone to be checked when they appear.
“More than 70 per cent of men with type 2 diabetes of any age might experience erectile dysfunction due to testosterone deficiency, suggests the BSSM.”
— Diabetes UK, citing the British Society for Sexual Medicine
Which symptoms overlap?
This is exactly where guessing goes wrong. The signs of low testosterone and the signs of poorly controlled diabetes look almost identical from the outside. The most common shared complaints are:
- Low sex drive and weaker or less frequent erections.
- Persistent tiredness that sleep does not fix.
- Low mood, irritability or trouble concentrating.
- Weight gain around the middle and loss of muscle.
Because the lists match, symptoms alone cannot tell you which problem is driving how you feel, or whether both are. Only a blood test can. That is the whole case for measuring rather than assuming.
Why does diabetes push testosterone down?
The low testosterone seen in diabetes is usually the secondary kind. That means the testes are healthy, but the brain is not sending a strong enough signal to make testosterone. The pituitary gland releases two messenger hormones, LH and FSH, and in these men that signal runs low or flat rather than ramping up to compensate.
Insulin resistance and excess fat tissue drive this. Fat tissue is hormonally active and raises inflammation, both of which dampen the brain’s testosterone signal. This is why weight sitting around the waist matters more than weight in general.
There is a measurement trap here too. SHBG, the protein that carries testosterone around your blood, tends to fall in insulin resistance. Low SHBG can drag your total testosterone reading down even when the active, free portion is less affected. That is why a good panel reads SHBG and free testosterone, not just the total on its own.
Which blood markers should you check?
If low testosterone is on the table, one number is rarely enough. A hormone panel worth having reads the full picture: total testosterone, free testosterone (the active portion), SHBG, and the pituitary signals LH and FSH. Together they show whether levels are genuinely low and where the problem sits.
Helvy’s Complete Male Hormones panel measures those markers in one home test, and our testosterone by age guide walks through how to read them against your age.
Blood-sugar markers such as HbA1c sit in a separate metabolic test, not the hormone panel, so many men check both. Our diabetes blood test guide covers what those numbers mean. Testing is about measuring your biomarkers for insight, not diagnosing a condition on its own.
What can you actually do about it?
The encouraging part of a two-way link is that one lever can move both. Losing excess weight, building muscle and improving how your body handles insulin tend to lift testosterone and improve blood sugar at the same time. Weight loss in particular is well shown to raise testosterone in men who are overweight.
One caveat matters. Testosterone treatment is not a diabetes treatment. UK and international guidelines do not recommend testosterone to control blood sugar, and any decision about hormone treatment belongs with a qualified clinician who has seen your full results and history. The value of testing is knowing your numbers, so any conversation starts from facts rather than guesswork.
Can you get this tested on the NHS?
Sometimes, but not by default. Despite the strength of the link, testosterone is not part of routine diabetes checks. If you have clear symptoms, especially erectile problems or persistent low libido, it is reasonable to ask your GP to test it.
Testosterone should be taken as a morning sample, and a low result is usually repeated before anything is concluded. If you would rather not wait, a private home panel lets you check the hormone markers together and read them alongside a clinician-written explanation.
Frequently asked questions
Does type 2 diabetes cause low testosterone?
It is strongly associated with it. Between a third and a half of men with type 2 diabetes have low testosterone, driven largely by insulin resistance, excess body fat and inflammation. The link runs both ways, so low testosterone also raises the future risk of diabetes.
Can raising my testosterone improve my blood sugar?
Guidelines do not recommend testosterone as a way to control blood sugar. Improving weight, muscle and insulin sensitivity is what tends to help both at once. Any hormone treatment is a decision for a qualified clinician based on your full results.
Which blood test should I take?
For the hormone side, a panel with total and free testosterone, SHBG, LH and FSH gives the fullest picture. Blood-sugar markers such as HbA1c sit in a separate metabolic test, so many men check both to see the whole situation.
Why do the symptoms of both feel the same?
Because they share biology. Fatigue, low drive, weight gain and poor erections all appear in low testosterone and in poorly controlled diabetes. That overlap is exactly why a blood test, not a symptom checklist, is the reliable way to tell them apart.
CHECK YOUR HORMONES
The Complete Male Hormones panel reads testosterone, free testosterone, SHBG, LH and FSH from a simple home sample, with a clear, plain-English explanation of every result. Build the test that fits your situation in two minutes.
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