Answer: Each hair follicle cycles through growth (anagen, lasting years), a short transition (catagen, a few weeks) and rest (telogen, about three months), after which the old hair sheds and a new one starts. Most scalp hairs are growing at any time. Because hair grows about 1 cm a month, any change from diet or supplements takes months to show.
- Anagen is the long growth phase and sets maximum hair length.
- Catagen is a brief transition lasting a few weeks.
- Telogen is a resting phase of about three months before shedding.
- Hair grows roughly 1 cm (half an inch) a month.
Why hair grows in cycles
Unlike skin, which renews continuously, each hair follicle works in cycles. It grows a hair for a period, shuts down, rests and then starts again. Crucially, every follicle runs on its own schedule. If they were synchronized, we would shed all our hair at once, as some animals molt. Instead, at any moment the scalp has a mix of follicles in different phases, so shedding is spread out and barely noticed.
The average adult scalp has around 100,000 follicles. Because they are staggered, losing a steady trickle of hairs each day is completely normal and is simply old hairs making way for new ones. Understanding the phases helps explain why hair changes, good or bad, show up months after their cause.
Anagen: the growth phase
Anagen is when the follicle is actively building a hair. Cells at the base, in the hair bulb, divide rapidly and push the hair shaft up and out. These are some of the fastest-dividing cells in the body, which is why hair is sensitive to nutrition, illness and some medicines.
On the scalp, anagen typically lasts from two to seven years, and most scalp hairs, often around 85 to 90 percent, are in this phase at any time. Its length mostly decides how long your hair can grow. Someone with a long anagen can grow hair to the waist; someone with a shorter one finds it stops at the shoulders. Eyebrows and body hair have much shorter anagen phases, which is why they stay short.
Catagen and telogen: transition and rest
- Catagen lasts about two to three weeks. Growth stops, the follicle shrinks, and the hair detaches from its blood supply, becoming a "club hair" with a small white bulb at the root.
- Telogen lasts about three months. The club hair stays in place while the follicle rests. Roughly 10 percent of scalp hairs are in telogen at any time.
- Shedding (sometimes called exogen) happens at the end of telogen, often nudged by brushing or washing, as a new anagen hair begins growing underneath.
That small white bulb on a shed hair is normal. It shows the hair completed its cycle. Our post on normal hair shedding covers how much is typical.
| Phase | Typical length and share of scalp hairs |
|---|---|
| Anagen (growth) | 2 to 7 years; most hairs, often 85 to 90 percent |
| Catagen (transition) | About 2 to 3 weeks; a small fraction |
| Telogen (rest) | About 3 months; roughly 10 percent |
| Shedding (exogen) | End of telogen; new hair starts beneath |
When the cycle shifts
Several things can push more follicles into telogen at once. A high fever, surgery, childbirth, a crash diet, major stress or certain medicines can trigger a wave. Because telogen lasts about three months, the extra shedding typically appears two to three months after the trigger, which is why people rarely connect the two. Doctors call this telogen effluvium, and it usually settles on its own once the cause passes.
Other conditions shorten anagen or shrink follicles over time, such as pattern hair loss. Low iron and thyroid problems can also affect the cycle; see iron and hair thinning. The American Academy of Dermatology: Hair Loss has clear explanations of the main types. Sudden, patchy or heavy hair loss needs a doctor or dermatologist, not a supplement.
Where a daily gummy like Gelagen fits
Because the follicle builds hair from protein, using energy and a range of vitamins and minerals, nutrition does matter, especially if your diet is short on something. Biotin is the best-known example, though the NIH ODS: Biotin fact sheet notes that deficiency is rare in people with a varied diet.
Gelagen is a daily gummy positioned mainly for skin, with hair and nail support also described by the brand. The most detailed seller page lists biotin, B12, B6, folate and pantothenic acid. See Gelagen ingredients and Gelagen benefits. It does not treat hair loss. If you try it, the hair cycle sets the timeline: new growth emerges slowly, and changes in hair already on your head are limited. Biotin can distort some lab tests, so tell your doctor before blood work.
What the cycle means for your timeline
Scalp hair grows roughly 1 cm, or about half an inch, a month. So any improvement in the hair your follicles make today becomes visible near the scalp only after a few months, and reaches the length of a typical bob much later.
Practical tips for judging any hair change:
- Photograph your part line in the same light every four weeks.
- Judge over at least three months, and ideally six.
- Do not count shed hairs obsessively; note trends instead.
- Change one variable at a time.
The brand describes fullest results over about six months, which matches the biology. If you choose Gelagen, buy from the Gelagen official website for the 60-day money-back guarantee, and read Gelagen questions and answers for practical details.
Think in months, not days
If you want daily support while you wait, see the Gelagen discount packages on our pricing page.
Get the Gelagen DiscountFrequently asked questions
How long does it take for hair to grow back after shedding?
A new hair usually starts growing as the old one sheds. At about 1 cm a month, it takes several months for regrowth to be noticeable.
Can supplements make hair grow faster?
Nutrition supports normal growth, especially if you are deficient, but there is no good evidence that supplements make healthy hair grow beyond its normal rate.
Why did my hair shed months after an illness?
Illness can push many follicles into the resting phase at once. They shed about two to three months later, then usually regrow.