Are collagen capsules just as effective as powder for hair?

Equal at zero: why the capsule versus powder question has no hair answer, and why collagen is the wrong protein for hair anyway

Are collagen capsules just as effective as powder for hair is a question that assumes the comparison has something to compare, and the honest page begins by checking the hair evidence for either format, because the comparison collapses the moment it is checked: neither has any. The question of whether capsules match powder in general has a real answer, worked through on the capsules versus powder page as four trial conditions, the form of collagen, its absorption, the dose and the duration, of which capsules meet the first two identically and fail the third at habit scale, since a 10g trial dose is around twenty capsules. But that answer presumes an outcome that a trial measured, skin elasticity, joint questionnaires, nail growth, and for hair there is no such outcome in any format. No randomised controlled trial has given collagen alone, as powder, capsule, liquid or gummy, and measured hair growth, hair density, hair shaft thickness or hair shedding against placebo. The trials that are quoted on hair-marketed collagen products gave proprietary oral complexes built around a marine protein extract combined with vitamin C, zinc, biotin, horsetail silica and other nutrients, and reported improved hair density and reduced shedding over three to six months in women with thinning hair; in those trials the marine protein cannot be separated from its passengers, several of which hold hair claims in their own right, and the product tested is not a collagen supplement but a hair complex that contains one, a distinction traced in full on the marine collagen and hair page. So on the hair question capsules and powder are exactly as effective as each other, at zero, and a reader choosing between them for hair is choosing between two untested things. The reason the evidence is empty is not an accident of research funding; it is that collagen is the wrong protein for hair. Hair is made of keratin, a family of proteins quite different from collagen in sequence and structure, and keratin is built heavily from cysteine, the sulphur-containing amino acid whose disulphide bonds give hair its strength and its curl, an amino acid that collagen almost entirely lacks, so that the amino acid profile a scoop of collagen delivers, a third glycine, a quarter proline and hydroxyproline, is nearly the opposite of what a hair follicle assembles. The follicle draws its amino acids from the body's general pool, which any protein eaten fills, and a reader eating enough protein of any kind has a follicle that is not short of cysteine or anything else; a reader eating too little protein, which does thin hair, is helped by more protein and by complete protein rather than by collagen's incomplete profile. The hair cycle makes the empty evidence harder to notice: hair grows about a centimetre a month and each follicle rests for around three months before shedding and restarting, so any change in density or shedding takes three to six months to show, during which season, stress, iron status, thyroid function and the end of a postnatal or post-illness shed all move hair far more than any supplement, and whichever tub was open at the time gets the credit; the clock is set out on the collagen and hair timing page.

The passenger list decides: the nutrients that hold the hair sentences, how to read a hair capsule, the six-month plughole baseline, and the worked example

What remains, once the collagen is set aside as equally untested in both formats, is a real comparison between what each format carries beside it, and that comparison does have a hair answer, because the register does. The authorised health claims for hair belong to four nutrients: biotin, zinc and selenium each contribute to the maintenance of normal hair, and copper contributes to normal hair pigmentation, with the claims permitted on a product that supplies at least fifteen percent of the nutrient's reference value per daily dose; no other nutrient and no protein, collagen included, holds a hair sentence, and a label that says collagen supports hair has stepped outside the register. Hair-marketed collagen capsules often add some of these passengers at claim-holding doses, biotin above all, since it is cheap and the public associates it with hair, along with zinc, selenium or a B-complex, so that the hair claims on the box are lawful because of the passengers and the collagen is along for the ride; a plain collagen powder carries collagen and nothing else and can make no hair claim at all. So a reader who wants a hair supplement reads the passenger list and ignores the collagen line: the questions are whether biotin, zinc or selenium are present at the fifteen percent threshold, whether the reader is plausibly short of any of them, which for a reader eating a varied diet is rare for biotin and selenium and uncommon for zinc, and whether the real drivers of hair thinning have been looked at, iron stores by a ferritin test, thyroid function, a recent illness, birth or weight loss, and the pattern of the loss, since a widening parting in a woman or a receding hairline in a man is a hormonal pattern that no nutrient addresses and a dermatologist does. A reader who wants collagen for the trials it does have, skin, joints, nails and the tendon protocol, chooses the format by dose and convenience exactly as on any other day, powder for the 2.5 to 15g trial doses and capsules for a 1 to 2g habit, and should expect nothing for hair from either. The honest baseline for a reader who takes anything for hair is a count: hairs collected from the plughole and brush over one set week before starting, repeated after six months, since shedding of fifty to a hundred hairs a day is normal and a count is the only instrument that beats the mirror's memory, with a parting photograph in fixed light as its partner; judged at six months, one hair cycle, and not before. The worked example illustrates the passenger logic in its own label, stated on its true terms: two capsules, 1200mg hydrolysed type 1 marine collagen with 12mg vitamin C at 15% of its reference value plus zinc, 120 for £16.99 at 28p a day, lab tested and UK made, in which the zinc holds the maintenance of normal hair sentence if it reaches its fifteen percent threshold, the vitamin C holds collagen formation for skin, and the 1200mg of collagen holds no hair claim and is below the 2.5 to 10g doses at which any collagen trial measured anything, so that a reader buying it for hair is buying the zinc and should know it. Are collagen capsules just as effective as powder for hair: equally effective at nothing that has been measured, with hair made of a protein collagen does not resemble, and the passengers, not the format, deciding what a hair product can lawfully say.

What to check on the label