Reproductive · Menstrual
Irregular cycles
Cycles that skip, shorten, lengthen, or change character after years of predictability are the single strongest signal from your reproductive system. They warrant investigation, not waiting.
Feels like
Does this sound like you?
- Cycles ranging 25–45 days over 6 months
- Missed periods without pregnancy
- Spotting mid-cycle
- Dramatically heavier or lighter flow
What to measure
The biomarkers that explain this symptom.
Grouped by the panel that tests them. We usually recommend running the top two panels together - patterns only show when you can see biomarkers next to each other.
Panel
hormones
- FSH / LHRatio identifies PCOS (LH:FSH >2:1) vs perimenopause (FSH climbing).
- EstradiolAnchor value for cycle-phase interpretation.
- ProgesteroneLuteal-phase progesterone confirms ovulation.
- Testosterone (Free) / SHBGPCOS signature.
- AMHOvarian reserve - adds context for 35+ women.
Panel
thyroid
- TSH / ProlactinBoth can disrupt cycles when elevated.
Patterns we see
Three common clusters.
Your specific pattern will be unique, but most people land in one of these.
01
PCOS signature
LH>FSH, free T elevated, SHBG low, insulin creeping up.
02
Perimenopausal
FSH rising into 20s-30s, cycles shortening then lengthening.
03
Hypothalamic
Low LH/FSH, low estradiol - often stress, under-eating, over-training.
Ready to look?
Order the hormones + thyroid panels.
Running the top two panels together is what lets us see patterns. Add a third if you want a fuller picture - most people benefit from the trio.
Further reading