Cycle Briefing  ·  Stephi
Moon phase

Cycle Timeline
Cycle Briefing  ·  Stephi
Your daily briefing
Your cycle
What should I call you?
Your cycle length
27
How long your period lasts
4
When did your last cycle begin?
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Cycle Briefing  ·  Stephi
Cycle science
How your hormones move
Hormone fluctuation across your cycle
Estrogen
Progesterone
LH
FSH
Estrogen
The rising hormone. Drives energy, sharpness, verbal fluency, and social confidence. Responsible for the rebuild after the bleed and the brightness of the pre-ovulatory peak.
Progesterone
The warming hormone. Rises after ovulation, producing calm, warmth, and an inward quality of attention. When it falls in late luteal, mood and sleep are directly affected.
LH — Luteinising Hormone
The trigger. Surges sharply at ovulation, signalling the follicle to release the egg. Its spike is brief and powerful — the peak of the entire cycle's outward arc.
FSH — Follicle Stimulating Hormone
The recruiter. Rises at the start of each cycle to develop follicles. Falls once the dominant one is selected. Has a smaller secondary rise at ovulation alongside LH.
Menstrual
What's happening
Estrogen and progesterone are at their lowest point. The uterine lining sheds — driven by prostaglandins, which are also responsible for cramping. FSH is beginning to rise quietly, already recruiting the follicles that will compete to lead the next cycle. The body is completing a full biological process that requires real energy.
Estrogen — lowest Progesterone — lowest FSH — beginning to rise Prostaglandins — high
What you feel
Fatigue, cramping, and low mood are all direct hormonal effects — not exaggeration. Pain perception is measurably higher during menstruation. Iron is actively being lost, which adds a genuine physical heaviness. The inner critic tends to be loudest here, at the hormonal floor.
Follicular
Early
FSH is rising and recruiting several follicles. Estrogen begins its climb from a low baseline. Serotonin sensitivity starts recovering — which is why emotional heaviness begins to lift. Curiosity tends to return before drive does.
FSH — rising Estrogen — climbing Serotonin sensitivity — recovering
Mid
The dominant follicle is selected and growing. Estrogen is building steadily. Dopamine receptor sensitivity improves — motivation, focus, and social appetite all increase. Cognitive sharpness and verbal fluency are measurably better than they were at the start of the cycle.
Estrogen — building Dopamine — returning Collagen synthesis — up
Late
Estrogen is approaching its pre-surge high. LH is beginning to build. The body is in one of its sharpest cognitive windows. Drive, confidence, and social energy are all high. Everything is building toward the peak.
Estrogen — near peak LH — beginning to rise Cognitive clarity — high
Ovulatory
What's happening
LH surges sharply, triggering the dominant follicle to release the egg within 24–36 hours. Estrogen and testosterone are both at their absolute cycle peak. After ovulation, the empty follicle becomes the corpus luteum and begins producing progesterone. The most outward moment of the cycle — crossing into the beginning of the inward arc.
LH — surges Estrogen — peak Testosterone — peak Progesterone — beginning to rise
What you feel
Verbal fluency, spatial awareness, and social confidence are all at their highest. Energy, presence, and magnetism peak here. Physical performance is at its monthly best — pain tolerance is high and coordination is sharp. The window is brief and distinct.
Luteal
Early
Progesterone is rising steadily. The corpus luteum — left behind after ovulation — produces progesterone, raising body temperature and resting metabolism. Estrogen holds and then begins to decline. Warm, stable, and capable in a quieter register than ovulation.
Progesterone — rising Estrogen — declining Body temperature — elevated Metabolism — higher
Mid
Progesterone is near or at its peak. It converts to allopregnanolone — a compound that binds to GABA receptors and produces genuine calm and a narrowing of social appetite. Metabolism runs 100–200 calories higher than baseline. The pull toward fewer people and more depth is directly hormonal.
Progesterone — peak Allopregnanolone — high Metabolism — elevated
Late
Progesterone begins to fall as the corpus luteum breaks down. Estrogen follows. This dual withdrawal directly reduces serotonin and dopamine — the biological cause of low mood, irritability, and heightened sensitivity. Amygdala reactivity increases by up to 30%, meaning emotional responses genuinely run larger than the situation warrants.
Progesterone — falling Estrogen — falling Serotonin — dropping Amygdala reactivity — elevated
Built around your cycle,
not against it.
What should I call you?
Your cycle length
28
How long your period lasts
5
When did your last cycle begin?

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