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)
Newborn
  Male75–400 ng/dL2.6–13.9 nmol/L
  Female16–64 ng/dL0.56–2.22 nmol/L
1–5 mo
  MaleLess than 360 ng/dLLess than 12.49 nmol/L
  FemaleLess than 20 ng/dLLess than 0.69 nmol/L
6–11 mo
  MaleLess than 40 ng/dLLess than 1.39 nmol/L
  FemaleLess than 9 ng/dLLess than 0.31 nmol/L
1–5 yr
  Male and femaleLess than 20 ng/dLLess than 0.69 nmol/L
6–7 yr
  MaleLess than 20 ng/dLLess than 0.69 nmol/L
  FemaleLess than 7 ng/dLLess than 0.24 nmol/L
8–11 yr
  Male2–165 ng/dL0.07–5.72 nmol/L
  Female1–30 ng/dL0.04–1 nmol/L
12–13 yr
  MaleLess than 600 ng/dLLess than 20.8 nmol/L
  FemaleLess than 50 ng/dLLess than 1.74 nmol/L
14–15 yr
  Male15–700 ng/dL0.52–24.29 nmol/L
  FemaleLess than 60 ng/dLLess than 2.08 nmol/L
Adult
  Male300–1080 ng/dL10.41–37.48 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)
7 mo–9 yr
  Male and femaleLess than 2 pg/mLLess than 7 pmol/L
10–11 yr
  MaleLess than 7 pg/mLLess than 25 pmol/L
  FemaleLess than 4 pg/mLLess than 14 pmol/L
12–13 yr
  MaleLess than 100 pg/mLLess than 347 pmol/L
  FemaleLess than 7 pg/mLLess than 25 pmol/L
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
  Male50–224 pg/mL173.5–777.28 pmol/L
  Female1–9 pg/mL3.47–31.23 pmol/L
Postmenopausal1–6 pg/mL
Older adult
  Male5–75 pg/mL17.35–260.25 pmol/L
  Female1–8.5 pg/mL3.47–29.5 pmol/L

Critical Findings and Potential Interventions
N/A

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