What LH tells you
Hormones are chemical messengers involved in energy, mood, body composition, and reproductive health. This group covers the key hormones a clinician may review when looking at these areas.
Which Honed panels include LH
LH is measured in the Hormone Panel. Every sample is collected at a pathology collection centre and processed at a NATA-accredited laboratory against RCPA reference ranges, with personalised plain-English commentary in your secure online report.
Why LH matters
Luteinising Hormone (LH) is a pituitary hormone that signals the testes in men to produce testosterone and the ovaries in women to release eggs and produce oestrogen and progesterone. LH is central to the hypothalamic-pituitary-gonadal (HPG) axis, the hormonal system that regulates sex hormone production. In men, LH stimulates testosterone synthesis in Leydig cells; in women, LH surge triggers ovulation. LH is highly dynamic, pulsing throughout the day and cycling in women.
The range explained
Low levels
Low LH (below 2 IU/L in men, below 5 IU/L in women outside the surge) suggests reduced pituitary signalling to the gonads. This can occur with lifestyle stress, overtraining, or hypothalamic dysfunction. A clinician interprets this alongside testosterone, FSH, and prolactin.
Normal range
Reference ranges: men 2–8 IU/L, women 2–10 IU/L (follicular phase), rising to 15–30 IU/L during the LH surge. These represent the normal pituitary signalling required for sex hormone production.
High levels
Elevated LH (above 8 IU/L in men, above 30 IU/L outside the surge in women) may indicate the gonads are not responding adequately to LH, or primary gonadal dysfunction. Requires clinical interpretation.
What affects LH
- Training: Overtraining and insufficient recovery suppress LH. Balanced training-to-recovery ratios support HPG axis function.
- Nutrition: Adequate energy intake, micronutrients (zinc, magnesium), and cholesterol support LH production. Undereating impairs LH pulsatility.
- Sleep: LH is partially sleep-dependent. Poor sleep disrupts the pituitary-gonadal axis.
- Stress: Chronic psychological stress elevates cortisol, which suppresses LH. This is a key mechanism by which stress impairs reproductive hormone production.
When to retest
Every 12 weeks when monitoring HPG axis function; every 12 months for general health. In women, timing within the menstrual cycle matters significantly.
Why athletes care
Athletes monitor LH as part of assessing HPG axis health; suppressed LH indicates overtraining or inadequate recovery and is associated with reduced testosterone production and recovery from training.
Related hormones markers
FAQ
What does the LH blood test measure?
Luteinising Hormone, released by the pituitary gland to signal the gonads. It is reviewed alongside sex hormones to help a clinician understand the hormonal axis.
Which Honed Health panels include LH?
LH is included in the Hormone panel.
What unit is LH measured in?
LH is reported in IU/L, measured at NATA-accredited laboratories against RCPA reference ranges, with personalised plain-English commentary in your secure report.