What it measures
- LH (luteinising hormone)
Who it’s for
- Trying to conceive
- Irregular periods or suspected PCOS
- Low testosterone in men
LH through your cycle
LH stays fairly level for most of your cycle, then surges for a day or two to release an egg. That surge is what home ovulation kits detect. A blood test on day 2 to 5 measures your baseline, which is most useful when compared with your FSH.
LH, PCOS and men’s health
In polycystic ovary syndrome, LH is often higher than FSH early in the cycle. That isn’t enough to diagnose PCOS on its own, but it can be a helpful clue. In men, LH shows whether low testosterone starts in the testes or with the brain’s signal to them.
How to prepare
- If you have periods, book for day 2 to 5 of your cycle (day 1 is the first day of full bleeding). If your periods are irregular or have stopped, any day is fine.
- Stop biotin (vitamin B7) supplements, often found in hair, skin and nail products, 48 hours before.
- No fasting needed. Eat and drink as normal.
When should I book?
How it works at our Croydon clinic
Book online
Choose your test and a time that suits you. No GP referral needed.
A 15-minute visit
A trained clinician takes a small blood sample at 169 Shirley Road, Croydon. Tell us if you’re nervous.
Results in 1–3 days
A clear report showing each result against its reference range.
Next steps
Share your report with your GP, who can arrange NHS follow-up if anything needs it.
Questions
Which day should I test?
Day 2 to 5 of your cycle. If your periods are irregular or absent, test on any day and tell us when you book.
Can men have an LH test?
Yes. Alongside testosterone, it shows whether low testosterone comes from the testes or from the brain’s signal to them.
How much is a LH Test in Croydon?
£55 at our clinic at 169 Shirley Road, Croydon, including taking your blood sample and your report.
How quickly will I get my results?
Usually within 1 to 3 days, in a clear report showing each result against its reference range.