Lunar Hair Cutting: What the Practice Is and What the Evidence Says
A plain explanation of a traditional practice, and an honest answer about whether it does anything.
Medically reviewed by Sarah Hitchcox, RN, BSN
The material previously published at this address is no longer available here.
What the practice is
Lunar hair cutting is the practice of scheduling haircuts according to the phase of the moon. It appears in farming almanacs and folk traditions in many parts of the world, alongside older customs of planting and harvesting by the moon. The common version holds that cutting hair during a waxing moon encourages faster or fuller growth, and that cutting during a waning moon slows growth and is better for keeping a style neat. Some traditions add the signs of the zodiac and give different recommendations for thickness, shine, or strength.
Various practitioners publish their own calendars and charts based on these ideas. Those calendars are their own work. We do not reproduce them here, and this site is not connected with anyone who produces them.
What the evidence says
There is no scientific evidence that the phase of the moon affects hair growth. Hair grows from follicles at an average of about one centimeter per month, driven by the follicle growth cycle, hormones, nutrition, age, and genetics. No published, controlled research has shown that lunar timing changes growth rate, thickness, or shedding.
Reviews of the wider question, whether lunar phase influences human biology at all, have generally found no reliable effect once study quality and chance findings are accounted for. Claims about the moon and body water are often repeated. Tidal forces act on very large bodies of water over long distances. The force on a person, or on a hair follicle, is negligible.
There is also a simple explanation for why the practice seems to work. Following a calendar means cutting hair on a regular schedule. Regular trims remove split ends and keep hair looking healthier, whatever the reason for the appointment.
Is there any harm
Timing haircuts by the moon is harmless. It costs nothing and it hurts nothing. It becomes a problem only if it replaces attention to a real cause of hair trouble. Sudden shedding, patchy loss, scalp pain, or scaling need a diagnosis, not a calendar.
What does affect hair
- Hair thinning in men and women, the causes worth ruling out and the treatments with real evidence behind them.
- Scalp health basics, including washing, flaking, and the tension from tight styles that damages the hairline.
- Sleep, stress, and your skin, which covers the diffuse shedding that follows a major stressor.
If your hair is changing and you do not know why, see a physician or dermatologist. Thyroid disease and iron deficiency are common, easily tested, and treatable.