Quick answer: Total testosterone measures all the testosterone in your blood, both bound and free. In men, low testosterone can cause low libido, fatigue, muscle loss and low mood. In women, high testosterone is often linked with PCOS, while low levels may affect libido and energy. Sleep, strength training, a healthy weight and stress care all support healthy levels.
Key takeaways
Total testosterone measures both the bound and free testosterone in the blood.
In men, low levels can bring low libido, fatigue, muscle loss and low mood, while in women high levels are often linked with PCOS.
Sleep, strength training, a healthy weight and stress care all support healthy testosterone.
What is Testosterone?
Testosterone is the main androgen. Men make it mostly in the testes; women make smaller amounts in the ovaries and adrenal glands.
Why Testosterone matters
Testosterone matters for muscle and bone strength, libido and sexual function, energy and mood, and red blood cell production.
Understanding your result
Reference ranges vary by lab, age and sex. Your provider interprets your result against the lab’s range and your overall picture, rather than chasing a single number. Functional labs are optional. They can be helpful in more complex cases.
What low Testosterone can mean
Low testosterone can reflect aging, obesity and insulin resistance, or poor sleep or sleep apnea. Chronic stress and over-training, opioids, steroids and some other medications, and pituitary or testicular conditions can also lower it.
What high Testosterone can mean
High testosterone can reflect PCOS in women, testosterone or anabolic steroid use, or adrenal conditions.
What affects Testosterone
Testosterone is affected by time of day (it is highest in the morning), sleep, body fat and insulin, and alcohol and medications.
Ways to support healthy levels
Strength training helps (see strength training for longevity), along with seven to nine hours of sleep and an evaluation for sleep apnea. Maintain a healthy weight and steady blood sugar, get adequate zinc, vitamin D and protein, and discuss testosterone therapy risks and benefits with your doctor.
What does the research show about total testosterone?
The European Male Ageing Study surveyed a random sample of 3,369 men aged 40 to 79 in eight countries and measured morning testosterone with mass spectrometry. Only three sexual symptoms, poor morning erections, low sexual desire and erectile dysfunction, clustered with low testosterone, and the researchers proposed defining late-onset low testosterone as those three symptoms plus total testosterone below 11 nmol/L (about 320 ng/dL) and free testosterone below 220 pmol/L (about 64 pg/mL). The study was cross-sectional and mostly in European men, so it cannot show cause and effect. (Wu et al., 2010)
The Testosterone Trials randomly assigned 790 men aged 65 and older with testosterone below 275 ng/dL and related symptoms to testosterone gel or placebo gel for one year. Testosterone rose into the normal range for young men and sexual activity, desire and erectile function improved modestly, but energy did not improve, and walking distance improved by 50 meters or more in 20.5% versus 12.6% only when all three sub-trials were pooled. The trial was too small and short to judge long-term heart or prostate risks. (Snyder et al., 2016)
In the UK Biobank, researchers followed 149,436 men aged 40 to 69 for about 11 years, during which 10,053 died. Men in the lowest fifth of testosterone had a 14% higher death rate than those in the highest fifth (hazard ratio 1.14), and calculated free testosterone showed similar results, while men with the lowest SHBG had a 32% lower death rate than those with the highest (hazard ratio 0.68). Testosterone was measured once by immunoassay, and observational data cannot show that changing these levels would change risk. (Yeap et al., 2021)
Taken together, a low testosterone number matters most when it is confirmed on a repeat morning test and matches symptoms. These studies were mostly in men, and the research on testosterone in women is much thinner.
Testosterone and healthy aging
Testosterone supports muscle, bone and metabolic health. Its tendency to decline with age is linked with muscle loss and changes in nutrient sensing and body composition.
Related tests and articles: free testosterone, SHBG.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have low libido, fatigue or muscle loss, or signs of PCOS. The same is true if you are considering testosterone therapy, or have abnormal results you want explained.
See a medical provider promptly for breast enlargement in men, a testicular lump, or rapid signs of virilization in women.
Testosterone at a glance
| Topic | What the article explains |
|---|---|
| Why it matters | Muscle and bone strength; libido and sexual function; energy and mood; and red blood cell production |
| What can affect it | Time of day (highest in the morning); sleep; body fat and insulin; and alcohol and medications |
| Supportive habits discussed | Strength training; seven to nine hours of sleep; get evaluated for sleep apnea; maintain a healthy weight and steady blood sugar; adequate zinc, vitamin D and protein; and discuss testosterone therapy risks and benefits with your doctor |
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Should my testosterone be drawn in the morning, and should we check SHBG at the same time?
How should I read my total testosterone alongside the rest of my labs and my symptoms?
How often would it make sense to recheck my total testosterone in my situation?
Which daily habits or medications could be influencing my total testosterone before we retest?
Frequently asked questions
When should testosterone be tested?
In the morning, ideally twice on different days, for men.
What causes low testosterone?
Aging, obesity, poor sleep, stress, medications and pituitary or testicular conditions.
Can I raise testosterone naturally?
Sleep, strength training, weight loss and stress care can help.
Do women need testosterone?
Yes, in small amounts for libido, energy and bone.
Sources
- Bhasin S, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2018. PMID: 29562364. https://pubmed.ncbi.nlm.nih.gov/29562364/
- Finkelstein JS, et al. Gonadal steroids and body composition, strength, and sexual function in men. N Engl J Med 2013. PMID: 24024838. https://pubmed.ncbi.nlm.nih.gov/24024838/
- Snyder PJ, et al. Effects of Testosterone Treatment in Older Men. N Engl J Med 2016. PMID: 26886521. https://pubmed.ncbi.nlm.nih.gov/26886521/
- Teede HJ, et al. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab 2023. PMID: 37580314. https://pubmed.ncbi.nlm.nih.gov/37580314/
- Wu FC, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med 2010. PMID: 20554979. https://pubmed.ncbi.nlm.nih.gov/20554979/
- Yeap BB, et al. Serum Testosterone is Inversely and Sex Hormone-binding Globulin is Directly Associated with All-cause Mortality in Men. J Clin Endocrinol Metab 2021. PMID: 33059368. https://pubmed.ncbi.nlm.nih.gov/33059368/
- MedlinePlus: Testosterone Levels Test
- MedlinePlus: Male Infertility
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
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