LH in men: what you need to know

What is LH?

LH (luteinising/ luteinizing hormone or lutropin) is one of the body’s chemical ‘messengers’. It is one of a family of hormones called gonadotropins, which also include follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG). Gonadotropins regulate and stimulate the growth and function of the gonads – ovaries in women and testes in men.

LH is produced by the pituitary, a pea-sized gland at the base of the brain consisting of two lobes, the anterior pituitary and the posterior pituitary. These sit below a brain structure called the hypothalamus, which is responsible for linking the endocrine system (the body’s hormonal messenger system) and the nervous system and keeping the body balanced in a stable state called homeostasis.

The Hypothalamus-Pituitary Complex. Source: Wikimedia Commons

The hypothalamus, the pituitary and the gonads (in men, the testes) work together in what is called the hypothalamic-pituitary-gonadal (HPG) axis.

When the hypothalamus secretes gonadatropin-releasing hormone (GnRH), this signals to the anterior pituitary to produce LH and FSH.

The Hypothalamic-Pituitary-Gonadal Axis. Source: Wikimedia Commons

What role does LH play in men?

In men, the LH produced by the pituitary gland stimulates Leydig cells in the testes to produce testosterone.

What are normal male LH levels?

The reference range for luteinising/luteinizing hormone for men is approximately between 1.3 and 8.0mIU/mL (international units per millilitre).

What do abnormal levels of LH mean?

High levels of LH in men can indicate so-called primary testicular failure, which can be due to defects in the development of the testes or to illness (e.g. adult mumps), injury, for example during sport, or due to treatment for cancer in the form of chemotherapy or radiation therapy. As a result, the testes are not responding properly to LH by producing enough testosterone.

On the other hand, low levels of LH can indicate that the pituitary gland is not producing enough of the hormone.

LH is one of the hormonal markers included within the Centre for Men’s Health’s regular blood test profiles, used for an initial full screen and examination of patients prior to any TRT treatment and as a part of ongoing monitoring of their progress during treatment.

Important Note: The Centre for Men’s Health can only offer diagnosis and treatment to patients who are based in the UK or who can attend appointments in our UK clinics in London and Manchester.

Links:

https://www.webmd.com/a-to-z-guides/luteinizing-hormone-test

https://www.pituitary.org.uk/information/what-is-the-pituitary-gland/