What happens to your body when you start taking collagen?

The gelatin dessert test: why the body cannot tell a supplement from jelly

What happens to your body when you start taking collagen is a question the shelf answers with a transformation story, and the honest page answers with a test the shelf would rather nobody ran, because the test is simple and the body passes it every time: the body cannot tell a collagen supplement from a daily serving of jelly. The reason is in the manufacturing and the digestion. Collagen supplements are made by taking hides, skins and scales, cleaning them, heating them in water and acid or alkali to denature the collagen into gelatin, the same gelatin that sets a dessert, thickens a stock and coats a gummy sweet, and then treating that gelatin with enzymes that cut its long chains into short peptides, which is what hydrolysed means; a collagen powder is gelatin that has been cut up in the factory so that it dissolves in cold water without setting, and a collagen capsule is that powder in a gelatin shell. In the body, the cutting continues regardless of where it started: the stomach's acid and pepsin and the small intestine's enzymes reduce gelatin from a dessert, collagen from a slow-cooked shin of beef, the connective tissue in pork scratchings and the hydrolysed powder from a tub to the same end products, free glycine, proline, hydroxyproline, alanine and the rest, plus the same handful of small di- and tripeptides that resist digestion, prolyl-hydroxyproline and hydroxyprolyl-glycine, which appear in blood for a few hours after any of them. The bloodstream receives identical material from all four sources, cannot tell which it came from, and treats it as it treats all amino acids and peptides, feeding whatever tissue is building and disposing of the rest. The one difference the supplement has is measurement: a capsule delivers a known number of grams, a jelly or a broth delivers a variable one, and the trials used known grams, which is why the shelf sells powder rather than jelly and why the honest comparison is with a daily measured portion of gelatin rather than with a vague one. The consequence for the question is direct. What happens to your body when you start taking collagen is exactly what would happen if you started eating a small measured portion of gelatin every day, which is a thing many people have done for years without noticing, and the body, which has been receiving gelatin from stock, gravy, sweets and meat all along, does not register a start.

What daily gelatin does in hours and in months, what it never does, and how you will know anything happened

What daily gelatin does in hours is the whole of the short-term answer. The portion is digested within an hour or two; the amino acids join the body's pool, where glycine and proline are topped up above what the day's other protein supplied, and are used by whatever tissue is making protein or deaminated in the liver with the nitrogen excreted as urea within a day; the surviving peptides peak in the blood around an hour after the portion and are cleared by evening; the hydroxyproline's oxalate is excreted the same day; and from a 10 or 15g portion a reader might feel a little fuller for an hour, as after any protein, and might, if the portion is taken in the evening, sleep a little better through the three to five grams of glycine it supplies, the one trialled effect of a glycine dose. Nothing is stored, no enzyme or receptor adapts, no tolerance builds and no withdrawal follows stopping, because the body treats a daily portion of gelatin as food and food does not do those things. What daily gelatin does in months, at the doses the trials used, is the trial readings, and the honest page states them as what a daily measured portion of gelatin would also be expected to produce, since the trials' collagen was gelatin cut shorter: at 2.5g a day and above, a few percent improvement in skin elasticity and hydration measured by cutometer and corneometer at eight to twelve weeks, invisible in a mirror; at 5 to 10g a day, modest improvement in knee osteoarthritis pain and function questionnaires at twelve to twenty-four weeks, with no cartilage change on imaging; at 15g with vitamin C about an hour before a loading session, a doubled blood marker of collagen synthesis; at 5g a day for a year in postmenopausal women, a small bone density gain in one trial. What it never does is the list the transformation story promises: it does not build muscle, since gelatin's three percent leucine and missing tryptophan do not switch synthesis on; it does not change body weight, except through its calories; it does not change hair or nails on any measured trial; it does not give energy or lift mood, having nothing that acts on the nervous system except glycine's sleep effect at scoop doses; and it does not accumulate as collagen anywhere, since no dietary protein is deposited intact. The body, in short, does not know it has started anything, and the only way a reader will know what happened is the method the trials used: one outcome written down before the first portion, an instrument-like substitute, a weekly score or a same-light photograph or a pain diary, and a reading at twelve weeks, with the first fortnight's good days discounted as the expectation they are. The worked example is a measured daily portion, 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, the gelatin equivalent of a small serving of jelly with the vitamin C and zinc beside it carrying their sentences, below the 2.5 to 15g research band and holding no claim for the collagen. What happens to your body when you start taking collagen: what happens when you start eating jelly every day, which is digestion, and the diary is how you will know if anything else did.

What to check on the label