Levels depend on a person’s age, sex, and health. Males usually have much higher levels of testosterone in their body than females.
Testosterone is a hormone known as an androgen. Although primarily known as a male sex hormone, females also need certain levels of testosterone. However, most testosterone converts into the sex hormone estradiol in the female body.
In males, the testes produce testosterone, and the ovaries produce testosterone in females.
The adrenal glands also produce small amounts of testosterone in both sexes.
Testosterone in males is important for:
- development during puberty
- sperm creation
- strengthening of muscles and bones
- sex drive
Testosterone in females is essential for:
- maintaining levels of other hormones
- sex drive and fertility
- making new blood cells
There is a link between low testosterone and sex drive and fertility for both sexes.
The body controls testosterone levels naturally and having low testosterone levels is more common than having high testosterone levels.
Typical testosterone levels
Low testosterone levels are more common than high levels.
Doctors measure testosterone in nanograms per deciliter (ng/dl).
The following tables show healthy levels of total testosterone in the body. Levels fall within a range for each age bracket.
People will have different levels of testosterone within this healthy range.
Infants and children
| Age | Male (in ng/dl) | Female (in ng/dl) |
| 0 to 5 months | 75-400 | 20-80 |
| 6 months to 9 years | Less than 7-20 | Less than 7-20 |
| 10 to 11 years | Less than 7-130 | Less than 7-44 |
Adolescents
| Age | Male (in ng/dl) | Female (in ng/dl) |
| 12 to 13 years | Less than 7-800 | Less than 7-75 |
| 14 years | Less than 7-1,200 | Less than 7-75 |
| 15 to 16 years | 100-1,200 | Less than 7-75 |
Adults
| Age | Male (in ng/dl) | Female (in ng/dl) |
| 17 to 18 years | 300-1,200 | 20-75 |
| 19 years and older | 240-950 | 8-60 |
Doctors may also measure testosterone alongside Tanner staging.
The Tanner scale tracks the visual development of children during puberty according to five fixed stages rather than a person’s specific age.
For example, stage II of the Tanner scale relates to the growth of a boy’s testicles or the development of breast buds in a girl, but it does not refer to their actual age.
Because hormone levels change rapidly during puberty and development can happen at different ages for different people, the Tanner scale is a more accurate way to judge changes during puberty than referring to age.
According to the Tanner scale, healthy testosterone levels are as follows:
| Tanner stage | Male (in ng/dl) | Female (in ng/dl) |
| I | Less than 7-20 | Less than 7-20 |
| II | 8-66 | Less than 7-47 |
| III | 26-800 | 17-75 |
| IV | 85-1,200 | 20-75 |
| V | 300-950 | 12-60 |
Low testosterone levels
Having a low testosterone level can lead to a low sex drive.
A testosterone deficiency in the womb can affect the development of a male fetus. It can also affect male puberty, and it may slow or stop a person’s growth or development.
Hormone levels change for both males and females as they age. Females experience a more dramatic change in hormones, with levels falling until a female reaches menopause. Males experience a more gradual change in hormone levels.
Testosterone levels decrease naturally with age in both sexes.
In males, lower testosterone levels can lead to:
- hair loss (including on the body and face)
- reduced muscle tone
- more fragile skin
- a reduced sex drive
- disturbed mood
- memory or concentration problems
Low testosterone levels in females can lead to:
- irregular or missed periods
- low sex drive
- vaginal dryness
- weak bones
- fertility problems
However, more research into the effects of low testosterone on the body as people age is needed.
High testosterone levels
High testosterone levels are unusual in adult males. Children with high testosterone levels may have a growth spurt or start puberty early. High testosterone in both sexes can cause infertility in some cases.
Polycystic ovary syndrome
Polycystic ovary syndrome (PCOS) affects females. It occurs when the ovaries produce too much testosterone.
- irregular or no periods
- oily skin
- acne
- increased hair growth on the face, back, or chest
It is not clear what causes PCOS, but researchers think it is a combination of genes and environment.
Steroid use
Steroids have similar properties to testosterone, and some people use them to build muscle or gain weight. However, steroids can affect testosterone levels in both males and females.
If a person takes too many steroids, it can raise the levels of testosterone in their blood, causing the body to stop producing testosterone.
In males, this excess of testosterone can also lead to a decrease in the amount of sperm that the body makes, which may lead to infertility or loss of sex drive.
For females, steroids can cause a deeper voice, male pattern baldness, irregular periods, and may lead to infertility.
Both males and females may experience hair growth on the face and body, greasy skin, and a range of other symptoms.
Testing and diagnosis
A doctor may order a blood test to diagnose low or high testosterone.
Anyone who suspects that their testosterone levels are high or low should see their doctor or get tested.
To diagnose low or high testosterone, a doctor will ask about a person’s medical history, do a physical examination, and order some tests.
In males, a doctor might:
- discuss any use of steroids or opiates
- talk about a person’s development at puberty
- measure their BMI and waist size
- check hair for any pattern of baldness
- check the size of the testicle and prostate gland
In females, a doctor will usually need to check or ask questions about:
- menstruation
- acne or skin conditions
- body or facial hair
- muscle bulk
For adolescents, a doctor will look for signs of puberty.
Total testosterone level test
The total testosterone level test is a blood test. The best time to have the test is in the morning when levels of testosterone in the blood are usually highest. However, testosterone levels vary throughout the day, so some people may need to have the test again to confirm the result.
Treatment options and takeaway
Treatment will depend on the underlying health condition.
It is possible to treat males for low testosterone levels with an injection or prescription gel. People using this treatment long-term could experience potentially severe side effects, such as an increased risk for heart problems.
Females who develop PCOS might be able to treat their symptoms with weight loss, hormonal contraception, and fertility treatment if needed.