Testosterone, Total and Free

General

Synonym/Acronym:
N/A

Rationale
To evaluate testosterone to assist in identification of disorders related to early puberty, late puberty, and infertility while assessing gonadal and adrenal function.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings
Method: HPLC/tandem MS for total testosterone and equilibrium dialysis for free testosterone.


Total Testosterone
AgeConventional UnitsSI Units (Conventional Units × 0.0347)
14–15 yr
Male33–585 ng/dL1.14–20.29 nmol/L
FemaleLess than 75 ng/dLLess than 2.6 nmol/L
16–17 yr
Male185-886 ng/dL6.42–30.74 nmol/L
FemaleLess than 20–75 ng/dLLess than 0.69–2.6 nmol/L
18–39 yr
Male300–1,080 ng/dL10.41–37.48 nmol/L
Female8–60 ng/dL0.28–2.08 nmol/L
Adult
Male300–890 ng/dL10.41–30.88 nmol/L
Female10–60 ng/dL0.35–2.08 nmol/L
Older adult
Male300–720 ng/dL10.41–24.98
Female5–32 ng/dL0.17–1.11
Postmenopausal levels are about half the normal adult level for females; levels in women who are pregnant are three to four times the normal adult level for females who are not pregnant.

Free Testosterone
AgeConventional UnitsSI Units (Conventional Units × 3.47)
14–15 yr
Male4–140 pg/mL13.88–486 pmol/L
FemaleLess than 10 pg/mLLess than 34.7 pmol/L
16–17 yr
Male38–173 pg/mL132–600 pmol/L
FemaleLess than 10 pg/mLLess than 34.7 pmol/L
Adult
Male50–244 pg/mL173.5–846.68 pmol/L
FemaleLess than 10 pg/mLLess than 34.7 pmol/L
PostmenopausalLess than 10 pg/mLLess than 34.7 pmol/L
Older adult
Male5–75 pg/mL17.35–260.25 pmol/L
FemaleLess than 10 pg/mLLess than 34.7 pmol/L

Critical Findings and Potential Interventions
N/A

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