For anyone feeling the pressure to have it all figured out by 25, take a breath. According to traditional Chinese medicine (TCM), you are far from hitting your peak.

The concept of TCM originates from the Huangdi Neijing, the foundational textbook of the practice, which was compiled during the Han dynasty (206BC-AD220). It describes human life as a series of predictable, energetic shifts, with bodily rhythms waxing and waning according to the balance of yin and yang – the passive and active forces that govern physical health.

Women’s lives are marked by seven-year stages governed primarily by blood – the substance that nourishes the body, fills the uterus, and is lost monthly through menstruation. This makes women inherently more yin in nature, because yin represents substance, coolness, stillness and the material aspects of the body.

The major female milestones mapped by the seven-year cycle – first menstrual period at 14, peak fertility at 28, menopause at 49 – are all directly tied to changes in blood and the yin-based reproductive essence called tian gui.

Men’s rhythms unfold slightly slower, every eight years, and are governed more by qi – the active, warming, moving energy that supports muscle function and physical drive. This is a yang quality, because yang represents function, heat and dynamic activity.

The milestones for men are therefore tied to yang and structural strength: a growth spurt in bones and tendons at 16, peak physical power at 32, and a gradual decline in bone density and yang energy after 40.

“Women mature earlier. We see it in puberty, and we see it in these cycles,” Hong Kong TCM practitioner Kelly Chan Sin-yiu says. “Men’s bodies develop at a slower rate, peaking later and declining more gradually.”