Low total testosterone

Written to our editorial standards · reviewed against published research· Updated 2 Jun 2026
A medical finding, review with a doctor

Low testosterone in men can cause fatigue, low libido, low mood, and loss of muscle, but the symptoms are non-specific, so a low result needs a morning retest and a doctor's review.

Testosterone is needed for libido, energy, mood, and muscle, and it dips with age, poor sleep, obesity, and low zinc or vitamin D. Because levels vary through the day and the symptoms overlap with many other conditions, a single low reading is confirmed with a second morning sample and interpreted by a clinician.

Common causes

  • Older age
  • Obesity
  • Poor sleep or sleep apnoea
  • Low zinc or vitamin D
  • Chronic stress or illness, some medications

Associated symptoms

  • Low libido
  • Fatigue
  • Low mood
  • Reduced muscle and strength
  • Erectile problems

Nutrients that can help

Zinc Picolinate
See the guide →
Vitamin D3 + K2
See the guide →
Ashwagandha KSM-66
See the guide →
What to do

Correct low zinc and vitamin D, prioritise sleep, strength training, and fat loss if overweight, which raise testosterone naturally. Confirm a low reading with a morning retest.

When to see a doctor

Do not self-diagnose. A confirmed low testosterone needs a doctor to find the cause and discuss whether treatment is appropriate.

Full marker
Total Testosterone: ranges, what it measures & both directions
Read the Total Testosterone guide →

Common questions

What does low testosterone mean?
Low testosterone in men can cause fatigue, low libido, low mood, and loss of muscle, but the symptoms are non-specific, so a low result needs a morning retest and a doctor's review. Testosterone is needed for libido, energy, mood, and muscle, and it dips with age, poor sleep, obesity, and low zinc or vitamin D. Because levels vary through the day and the symptoms overlap with many other conditions, a single low reading is confirmed with a second morning sample and interpreted by a clinician.
What causes low total testosterone?
Older age; Obesity; Poor sleep or sleep apnoea; Low zinc or vitamin D; Chronic stress or illness, some medications.
How do I raise my total testosterone?
Correct low zinc and vitamin D, prioritise sleep, strength training, and fat loss if overweight, which raise testosterone naturally. Confirm a low reading with a morning retest.
When should I see a doctor?
Do not self-diagnose. A confirmed low testosterone needs a doctor to find the cause and discuss whether treatment is appropriate.

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Educational use only, not medical advice or diagnosis. Reference ranges vary by lab, age, sex, and medication, and a single result is read in context. Always review your results with a qualified clinician.