Testosterone

Written by Zayn Miah & R KhanomLast updated 17 September 2026Not clinically reviewed

A hormone important for sperm production in men, sometimes measured as part of a male fertility assessment.

In plain English

It's a hormone checked in some fertility blood tests, particularly relevant to sperm production in men.

Why it matters

Low levels can be linked to reduced sperm production, so it's sometimes part of investigating male factor infertility.

Related terms

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Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.