Why Hair Sheds, And What Helps

Published 2026-08-21 · 9 minute read · Gelagen Notes

Everybody loses hair every day and most people have no idea how much is normal, which is why a handful in the shower drain produces so much anxiety. The number usually quoted is fifty to a hundred hairs a day, and it is an average across a scalp carrying around a hundred thousand of them.

The Cycle, Which Explains Almost Everything

Each follicle runs its own independent cycle in three phases.

Anagen is growth, and it lasts between two and seven years. The length of your anagen phase is largely genetic and it sets the maximum length your hair can reach, which is why some people can grow hair to the waist and others physically cannot.

Catagen is a short transition of a couple of weeks where the follicle detaches from its blood supply.

Telogen is rest, around three months, at the end of which the hair is released and a new one begins growing underneath.

At any moment roughly eighty-five percent of your follicles are in anagen and around ten to fifteen percent in telogen. Because each follicle runs independently, shedding is normally spread evenly and invisibly across the scalp.

What Goes Wrong: The Synchronised Shed

Telogen effluvium is what happens when a large number of follicles are pushed into the resting phase at the same time. Three months later they all release together, and the experience is dramatic: handfuls, a visibly thinner ponytail, hair on the pillow.

The trigger list is consistent and it is worth reading carefully, because almost every entry on it is a thing that happened three months before the shedding started.

• Childbirth, which is the commonest cause of all
• A high fever or serious infection
• Surgery or a general anaesthetic
• Rapid weight loss or severe calorie restriction
• Iron deficiency, and sometimes thyroid disease
• Starting or stopping hormonal contraception
• Severe psychological stress or bereavement

The three-month delay is why people so often connect the shedding to whatever is happening the week it starts rather than to the event that actually caused it. Look backwards a season, not a fortnight.

The Good News Nobody Leads With

Telogen effluvium is self-limiting. The follicles are not damaged, they were interrupted, and they restart. Most cases resolve within six to nine months without any treatment at all.

That matters commercially, because it is the window in which people buy supplements and then attribute a recovery that was going to happen anyway. We would rather say so than accept credit for a biological timetable.

What Is Not Telogen Effluvium

Pattern hair loss follows a shape — a receding hairline, a widening parting, thinning at the crown — and it is progressive rather than self-limiting. It has effective medical treatments and it needs a diagnosis.

Patchy round bald spots suggest alopecia areata, an autoimmune condition, and that is a dermatologist rather than a shelf.

Shedding with scalp pain, burning or visible scarring is urgent. Scarring alopecias destroy follicles permanently and early treatment is the whole game.

Where Nutrition Genuinely Fits

Narrowly, and it is worth being precise about the edges.

Iron is the clearest link. Low ferritin is genuinely associated with shedding, particularly in menstruating women, and correcting it helps. Iron is not on our panel, and if you suspect it, ask for a ferritin test rather than buying anything.

Zinc and B12 matter when genuinely low, which is a smaller group of people than the marketing implies.

Biotin influences shaft assembly rather than growth rate. The reports that come to us describe less breakage and better length retention, which is exactly what the mechanism would predict and considerably less than the category usually promises.