The Importance of Testosterone

Testosterone is often associated with muscle mass and masculinity but this hormone does much more, and it's essential for the health of all genders. Produced by the adrenal glands, ovaries, and testes, testosterone is a type of androgen hormone involved in everything from sexual development to mood, metabolism, and cognitive function.

While it’s typically viewed as the “male” hormone, testosterone plays a vital role in female health, too. Here's why testosterone matters, what happens when levels are too low or too high, and how to know if your body is in balance.

The Role of Testosterone in the Body

Testosterone has both reproductive and non-reproductive functions. It helps regulate:

• Sperm and egg production
  In men, testosterone is necessary for sperm development. In women, androgens like testosterone are involved in ovarian follicle development and estrogen production.

• Secondary sex characteristics
  During puberty, testosterone drives changes such as facial hair growth, voice deepening, and increased muscle and bone mass in cisgender males.

• Muscle and bone strength
  Higher testosterone levels support greater lean muscle mass and bone density one reason why men tend to have more muscle and fewer fractures than women.

• Sex drive (libido)
  Testosterone increases sexual desire in all genders. Low levels can result in decreased libido.

• Cognitive functions
  Testosterone is linked to learning, memory (especially spatial awareness), and emotional regulation. Low levels may be tied to learning difficulties or mood issues.

• Pain tolerance
  Some studies suggest testosterone helps regulate pain perception.

Testosterone Levels: What’s Normal?

Testosterone levels vary by sex, age, and time of day. In general, healthy cisgender men have about 15 times more testosterone than healthy cisgender women.

Here are general reference ranges:

1. Assigned male at birth (age 19+):

   • Total testosterone: 270–1070 ng/dL

   • Free testosterone: 50–210 pg/dL

2. Assigned female at birth (age 19+):

   • Total testosterone: 15–70 ng/dL

   • Free testosterone: 1.0–8.5 pg/dL

For accuracy, testosterone blood tests are typically done in the morning, especially in men under 45 when levels are highest.

When Testosterone Levels Are Out of Balance

Too little or too much testosterone can disrupt health across all body systems. Here’s how:

Low Testosterone Symptoms

• Fatigue or low energy

• Reduced muscle mass or strength

• Decreased libido

• Mood changes (depression, irritability)

• Difficulty concentrating

• Infertility

• Weakened bones

Causes of Low Testosterone in Men:

• Age (especially after 50)

• Obesity or being underweight

• Testicular conditions or injury

• Pituitary gland disorders

• Cancer treatments

• Certain medications

• Extreme stress

Common Cause of Low Testosterone in Women:

• Menopause, which naturally reduces androgen levels

High Testosterone Symptoms in Women

• Excess facial/body hair

• Acne or oily skin

• Hair thinning or male-pattern baldness

• Irregular periods or infertility

Causes of High Testosterone in Women:

• Polycystic ovarian syndrome (PCOS)

• Congenital adrenal hyperplasia (CAH)

• Adrenal or ovarian tumors

• Steroid abuse

High testosterone in men is less common but can result from anabolic steroid use, tumors, or testosterone supplementation and can cause aggression, infertility, and increased cardiovascular risk.

How Testosterone Is Used in Medicine

Approved Uses:

• Testosterone is FDA-approved to treat hypogonadism (low testosterone due to medical conditions) in cisgender men and delayed puberty in boys.

Other Medical Uses:

• Transmasculine individuals may use testosterone as part of gender-affirming hormone therapy.

• In certain cases, testosterone is used off-label to support libido or perimenopausal symptoms in women, though it is not FDA-approved for this purpose.

Forms of Testosterone Therapy Include:

• Injections

• Gels and topical solutions

• Skin patches

• Implantable pellets

• Oral capsules

Brand names include: AndroGel, Testim, Natesto, Testopel, Depo-Testosterone, and more.

Risks of Testosterone Supplementation

Testosterone is a powerful hormone and should never be taken without medical supervision. Risks include:

• Infertility in all genders

• High blood pressure

• Heart attack or stroke

• Blood clots (DVT or pulmonary embolism)

• Liver problems

• Enlarged prostate or risk of prostate cancer

The FDA warns against using testosterone for age-related low T, as the risks often outweigh the benefits. However, the Endocrine Society supports careful use in older men with confirmed deficiency, under medical supervision.

Important: Over-the-counter or online “testosterone boosters” are often unsafe, unregulated, or fake. Always consult a healthcare provider before beginning any hormone therapy.

Testing Your Testosterone

If you’re experiencing symptoms, ask your healthcare provider about total and free testosterone testing. These levels help your doctor assess whether your symptoms are related to a hormonal imbalance and guide treatment accordingly.

Final Thoughts

Testosterone plays a vital role in reproductive, physical, and emotional health for all people. Whether you’re noticing changes in your mood, energy, sex drive, or physical strength, it may be time to look deeper into your hormone levels. With professional guidance, imbalances can often be corrected safely.

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