Follicle-Stimulating Hormone

also known as FSH

NORMAL_RANGE
1.5 – 12.4 mIU/mL
UNIT
mIU/mL

/WHAT_IT_IS

FSH is the pituitary signal that drives sperm production in the testes. Like LH, it's suppressed on TRT.

/NORMAL_RANGE

Adult male reference: 1.5–12.4 mIU/mL.

What does high FSH mean?

  • +Primary testicular failure.
  • +Sertoli cell-only syndrome.
  • +Klinefelter syndrome.

What does low FSH mean?

  • +Exogenous testosterone, AAS use.
  • +Secondary hypogonadism.

/ON_TRT

FSH falls to near-zero on TRT, which is why sperm production crashes and most men become temporarily infertile after 3–6 months of therapy. If preserving fertility matters, hCG plus low-dose hMG or recombinant FSH can maintain spermatogenesis during TRT.

/RELATED

FAQ

/01Will TRT make me infertile?+

TRT suppresses FSH and stops sperm production in most men within 3–6 months. Fertility usually returns within 6–24 months of stopping — but not always, and the data is increasingly mixed on long-term fertility recovery. If kids are on the roadmap, use hCG alongside TRT and bank sperm before starting.

/TRACK_THIS

Track FSH in the app.

Upload your lab PDF — MyTRT extracts every marker with Gemini Vision. Charts, trends, and TRT-aware insights. Free on iOS and Android.

Last reviewed: 2026-06-04 · MyTRT does not provide medical advice. Always consult your physician.