FSH and LH Report: Day 2 Hormones, PCOS Ratio and Menopause
The short answer: FSH and LH are the brain’s two “wake up” signals to the ovaries, and they only make sense when you know which cycle day the blood was taken, which is why doctors ask for day 2 or 3; a high FSH on that day can signal a shrinking egg reserve or menopause, while the famous LH:FSH ratio is no longer used to diagnose PCOS.
Before you start
- Timing: day 2 or 3 of the period (day 1 is the first day of real flow).
- Units: IU/L or mIU/mL, which are the same size.
- Big clue: a clearly high FSH twice, with missed periods before 40, needs a specialist.
- The ratio: an LH higher than FSH is a hint, never a PCOS diagnosis.
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You’re handed a lab slip that says “Day 2 hormones” and wonder why the date of your period decides when you get a needle. Then the report comes back with ranges split into phases, follicular, mid-cycle, luteal, postmenopausal, and your number seems to fit one column and not another. This Lab Reports Decoded guide sorts the columns out. It won’t replace your doctor’s reading.
What FSH and LH do, simply put
Picture the pituitary gland as a coach on the sidelines and the ovaries as the players. At the start of each cycle the coach shouts “FSH!” (follicle-stimulating hormone), and a few follicles start growing their eggs. When one follicle is ready, the coach blows a loud whistle: a sudden burst of “LH!” (luteinising hormone). The egg pops out. Ovulation.
When the ovaries are doing well, they call back to the coach with their own hormones, mainly estrogen, and the coach lowers his voice. When the ovaries run low on eggs, the coach can’t hear an answer, so he shouts louder. That’s why FSH rises as menopause approaches.
Why day 2 or 3?
Early in the cycle, the hormones are at their quietest and most comparable. Same starting line. A high FSH stands out. Test mid-cycle and you might catch the LH surge, which can read many times higher than normal and look alarming for no reason at all. Did you know? Home ovulation kits simply detect that same LH surge in urine.
If you have no periods at all, doctors may test on any day, sometimes after a short course of medicine they prescribe to bring on a bleed. Their call.
How to read the report by cycle phase
Typical lab ranges, which vary by lab; use the range printed on your report. Most labs print separate ranges for each phase. The table shows the broad pattern, not exact cut-offs.
| Phase | FSH | LH |
|---|---|---|
| Early cycle (day 2 to 5) | Low to moderate, often single digits | Low to moderate, similar to FSH |
| Mid-cycle | Brief rise | Sharp surge |
| After ovulation | Low | Low |
| After menopause | High, often very high | High |
As a rough guide, many labs give an early-cycle FSH range with an upper limit around 10 IU/L. Many fertility clinics start paying attention once a day 2 FSH climbs above about 10, and a value above about 25 IU/L on two tests 4 to 6 weeks apart, with missed periods before 40, is one of the markers doctors use for premature ovarian insufficiency. Estradiol is often tested on the same sample, because a high estradiol can hide a high FSH.
Why values are high or low
High FSH (and often LH)
- Normal perimenopause and menopause: usually in the 40s and 50s. FSH can swing wildly month to month in the years before the last period, so one reading can mislead.
- Early ovarian ageing before 40 (POI): see our early menopause guide for the signs and why treatment protects bones and heart.
- After chemotherapy, radiation or ovarian surgery.
- Some genetic conditions, such as Turner syndrome, which doctors check with separate tests.
Low FSH and LH
When both are low and periods are missing, the coach himself is quiet. Common reasons include heavy stress, too little food or rapid weight loss, very intense exercise, high prolactin, and less commonly a pituitary problem. Hormonal birth control also keeps both low on purpose, so the test is often meaningless while you take it. Pregnancy lowers them too.
Myth: an LH to FSH ratio above 2 means PCOS
The ratio was once popular. Many women with PCOS do have an LH higher than FSH, which is exactly how the idea caught on in clinics and then spread through forums and family WhatsApp groups as if it were a test result on its own. But plenty don’t, and the modern diagnosis rules (irregular or absent ovulation, signs of raised male hormones, and the ovary ultrasound pattern, needing two of the three) don’t use the ratio at all. Slim women show it more. So a “normal ratio” doesn’t rule PCOS out, and a raised one doesn’t rule it in. If you’re sorting this out, our PCOS vs PCOD guide walks through the real criteria.
The same FSH number can be normal in one column and worrying in another. The cycle day decides.
How to prepare for day 2 hormone tests
- Mark day 1 as the first day of full red flow, not spotting.
- Go for the blood test on day 2 or 3, ideally in the morning; no fasting is needed unless other tests are on the slip.
- Tell the lab and doctor if you take the pill, use a hormonal coil, or are breastfeeding.
- If periods are absent, ask the doctor which day to test instead of guessing.
- For a repeat test, use the same lab and the same cycle day for a fair comparison.
FSH and LH in men
Men make both too. FSH drives sperm production and LH drives testosterone. High FSH with a low sperm count suggests the testes themselves are struggling; low FSH and LH with low testosterone point the doctor towards the pituitary. Men should always have these read by a urologist or endocrinologist, and should avoid testosterone products bought online, which can shut down sperm making.
Book a gynaecologist visit if periods stop for 3 months or more (with a negative pregnancy test), if periods stop or hot flushes start before 40, or if you’ve been trying to conceive for 12 months (6 months at 35 or over). Go the same day for very heavy bleeding, fainting, severe pelvic pain or new headaches with vision changes. Hormone reports are interpreted by your doctor, and any hormone treatment is their decision.
FSH and LH report questions
What is the normal FSH level on day 2?
Many labs give an early-cycle upper limit of around 10 IU/L, but ranges vary by lab. Always compare with the phase-specific range printed on your report.
Why is FSH tested on day 2 or 3 of the period?
Hormones are at their quietest then, so results can be compared fairly. Testing later can catch normal rises that look falsely alarming.
What does high FSH mean before 40?
With missed periods, a high FSH on two tests weeks apart may signal premature ovarian insufficiency. A specialist confirms it and discusses treatment to protect bones and heart.
Is the LH:FSH ratio used to diagnose PCOS?
No. It can be a hint, but modern PCOS rules rely on ovulation problems, signs of raised male hormones and the ultrasound, needing two of the three.
What is a normal LH level in females?
It depends on the cycle phase. LH is low to moderate early in the cycle, surges sharply before ovulation and is high after menopause. Use the phase range on your report.
Can FSH confirm menopause?
In women over 45 with typical symptoms, doctors usually diagnose menopause from periods alone. FSH swings too much in the years before menopause to be a reliable single test.
Can stress change FSH and LH?
Heavy stress, low food intake and very intense exercise can lower both and stop periods. The doctor looks at the whole picture, including weight and prolactin.
Does the birth control pill affect FSH and LH results?
Yes. The pill keeps both low on purpose, so testing while on it rarely helps. Ask the doctor about timing if a test is needed.
What if periods are irregular, which day should the test be done?
Your doctor will choose. Sometimes any day is used, sometimes a bleed is brought on first. Don’t guess, because the day changes the meaning.
Can FSH be high one month and normal the next?
Yes, especially in the late 30s and 40s. That’s why one reading is never the full story and a repeat is common.