How long does collagen take to work on hair?

The hair cycle as the clock, and why anything acting on hair takes three to six months to show

How long does collagen take to work on hair is a question whose first half has a precise answer and whose second half has an honest one, and the page gives both in that order, because the clock belongs to the hair and not to the tub. The hair cycle sets the clock. Scalp hair grows about a centimetre a month, and each follicle runs through a long growth phase of two to six years, a brief regression of a few weeks, and a resting phase of around three months at the end of which the hair sheds and the follicle begins a new one, with around a tenth of a scalp's follicles resting at any time and fifty to a hundred hairs shedding a day as a normal consequence. The arithmetic of that cycle is what makes every hair question a slow one: the hairs a reader sees and sheds today were decided by follicles months ago, so a nutrient corrected, a stress passed, an illness recovered from or a medicine started changes what the follicles do now and shows in the brush and the mirror three to six months later, when the follicles that responded have moved through their resting phase and the new hairs have grown enough centimetres to count, the hair cycle literature's timescale, and this is true of everything that acts on hair, iron for a reader who was short of it, thyroid treatment for a reader who needed it, the prescription treatments for pattern loss, and the passing of the shedding that follows a fever or a birth. So the first half of the answer is that if collagen did anything to hair, it would take three to six months to see, the same as anything else, and a reader judging any hair supplement at eight weeks is judging hairs that were decided before the tub was opened. That is the clock, and it is worth knowing on its own, because it is why the before-and-after hair photographs at four and eight weeks on the shelf are photographs of styling and light.

Collagen's empty seat, the proteins compared, the register's hair sentences, and the reader with real shedding

The second half is whether collagen has a seat on that clock at all, and the honest answer is that it does not, for three reasons the page gives in turn. First, the trials: no collagen trial has measured hair density, hair shedding, hair thickness or hair growth rate as an outcome, the oral collagen trials measured skin by instrument and joints by questionnaire and tendon by synthesis marker, and the hair claims on collagen tubs are extrapolations from the skin trials and from the fact that hair grows out of skin, which is true and is not a trial. Second, the proteins: hair is made of keratin, a protein rich in the sulphur amino acid cysteine, whose disulphide bonds crosslink the keratin and give hair its strength and its shape, while collagen is a third glycine with proline and hydroxyproline and contains almost no cysteine, so the idea that eating collagen supplies the building blocks of hair has the chemistry backwards, the building block hair needs most being the one collagen most lacks, and the amino acids hair does need arriving in adequate quantity from any complete protein diet at 1.6 grams per kilo, which collagen does not count toward. Third, the register: the UK claims register's hair sentences belong to biotin, zinc and selenium, each of which contributes to the maintenance of normal hair, and to copper, which contributes to normal hair pigmentation, and collagen holds none, so a collagen tub that mentions hair is borrowing a line from the zinc or biotin beside it, which is lawful about the zinc or biotin and says nothing about the collagen, and the honest capsule that includes zinc may carry zinc's hair sentence and says so. A different reader deserves a different paragraph: a reader who searched this because they are shedding more than the normal fifty to a hundred hairs a day, finding hair on the pillow and in the plughole, has a set of common, checkable causes, low iron, thyroid, the shedding that follows an illness or a birth or a major stress by three months, some medicines, and pattern loss with its own treatments, and every one of those is a conversation with a doctor and a blood test rather than a tub, since a three-to-six-month experiment with collagen on shedding hair is three to six months in which the cause went unlooked for. The worked example carries the one hair sentence on this page and states its terms: two capsules, 1200mg hydrolysed type 1 marine collagen with 12mg vitamin C plus 1.5mg zinc, 120 for £16.99 at 28p a day, lab tested and UK made, the collagen below the research band and taken for vitamin C's collagen formation sentence, the zinc contributing to the maintenance of normal hair, at 15% of its reference value, a modest line honestly held. How long does collagen take to work on hair: the clock says three to six months for anything, and the evidence says collagen is not on it.

What to check on the label