Have you ever said to yourself, “I never know what she wants? I’m not even sure she knows what she wants. One minute she’s fine... then she suddenly isn’t! What’s going on?” Before you decide to give up, there’s a logical answer. Take a look at these two hormone charts.

The Inside Scoop

On Girls

A chart showing hormone levels over a month, with testosterone levels represented by a green line and follicle stimulating hormone (FSH) levels by a blue line, both remaining steady.

Guys

In men, the Follicle-Stimulating Hormone (FSH) acts on the Sertoli cells of the testes to stimulate sperm production (spermatogenesis).[1] So, adult males are hormonally consistent from day to day. During puberty, guys can have mood swings, but they don’t fluctuate cyclically like a woman’s does during her cycle.

Graph titled "A 'Typical' 28-Day Menstrual Cycle" showing four hormone levels: FSH in blue, LH in purple, Estrogen in pink, and Progesterone in green across 28 days. The cycle is divided into phases: Menstruation (days 1-5), Follicular (days 6-14), Ovulation (around day 14), and Luteal (days 15-28). The hormone levels fluctuate according to the phase of the menstrual cycle.

Girls

In women, progesterone, estrogen, and LH all surge and fall during her cycle, impacting her moods, appetite, and energy.[2] This isn’t an excuse for girls to be mean, but it might help you understand a little better why your mother, sister, girlfriend, or classmates act the way they do.

What’s She Feeling?

Here’s a cheat sheet for you. While her emotions and reactions may still be confusing, hopefully knowing a bit about what she’s experiencing internally will help you to understand her a little bit better.

Menstrual Phase (Period)

Hormones are low.
Her emotions are generally low and can be more volatile.

Follicular Phase

Hormones and energy are on the rise. She’s generally happy and excited.

Ovulatory Phase

Hormones and energy peak. Her emotions are intense, for better or worse, and she’s ready to conquer the world.

Luteal Phase

Hormones and energy start falling. She’s less interested in doing things and starts turning inward.

1. “Follicle Stimulating Hormone.” You and Your Hormones, https://www.yourhormones.info/hormones/follicle-stimulating-hormone/. Accessed 20 February 2026.

2. “Hormones.” You and Your Hormones, https://www.yourhormones.info/hormones/. Accessed 20 February 2026.