Luteinizing Hormone
Also called LH.
Luteinizing hormone (LH) is released by the pituitary gland and signals the testes to produce testosterone. In My TRT App you can log LH after each draw and see it next to your dose history. Each lab sets its own reference range, so compare against the range printed on your report.
What it is
Luteinizing hormone (LH) is released by the pituitary gland and signals the testes to produce testosterone. On TRT it falls to near-zero because exogenous testosterone shuts down the HPTA.
Reference range
| Reference range | Unit |
|---|---|
| 1.7 – 8.6 | mIU/mL |
Adult male reference: 1.7–8.6 mIU/mL.
What moves it
- Primary hypogonadism (testicular failure) — testes can't respond, pituitary keeps shouting.
- Pituitary tumor (rare).
- Exogenous testosterone (TRT, AAS) — the most common cause.
- Secondary hypogonadism (pituitary or hypothalamic problem).
- Hyperprolactinemia.
On TRT
LH almost always reads <1.0 mIU/mL on TRT — that's expected and not a problem in itself. Men trying to preserve fertility add hCG (which mimics LH) to maintain intratesticular testosterone production. If you're planning to come off TRT, monitoring LH recovery is part of the restart protocol.
Related markers
FAQ
Will LH come back after stopping TRT?
For most men, yes — but it can take 3–12 months, and a small percentage don't fully recover. The longer you've been on TRT and the higher the dose, the longer recovery typically takes. Restart protocols often use clomiphene or hCG to accelerate recovery.
What does luteinizing hormone do in men?
LH is released by the pituitary gland and signals the Leydig cells in the testes to produce testosterone. It's the main upstream driver of your natural testosterone output. The adult male reference range is roughly 1.7–8.6 IU/L.
What is the relationship between LH and testosterone?
The brain and pituitary release LH, which tells the testes how much testosterone to make; rising testosterone then feeds back to dial LH down, keeping levels balanced — the HPG axis. When testosterone is low from a testicular problem, LH usually runs high as the pituitary tries to compensate. When it's low from a pituitary or hypothalamic problem, LH is low or normal alongside low testosterone.
Why is LH near zero on TRT?
Exogenous testosterone tells the brain that plenty of hormone is present, so the pituitary stops releasing LH through negative feedback. LH typically reads under 1.0 IU/L on TRT, which is expected rather than a problem. Because the testes lose their LH signal, men who want to preserve fertility or testicular size often add hCG, which mimics LH.
Read it in context, not alone.
One LH result is a snapshot. Logging each result in My TRT App next to your dose timing gives you and your prescriber a clearer picture over time.
Last reviewed 2026-09-02. Education only, not medical advice. Always talk to your prescriber.
Log this marker after every draw.
Scan your lab report and see each result on a trend line.
