Does collagen help tendon repair?

Repair one: the ruptured or surgically repaired tendon, where collagen is untested

Does collagen help tendon repair is a question whose word repair means two different things to a tendon, and the honest page splits it before answering, because collagen's evidence belongs to one meaning and the shelf borrows it for both. Repair one is the repair of a ruptured or surgically repaired tendon: the Achilles that snapped on a push-off, the biceps tendon that tore at the elbow, the rotator cuff stitched back to the bone, a tendon whose continuity was lost and is being re-established. That healing runs through the three stages the tendon healing literature describes, an inflammatory stage of days, a proliferative stage of weeks laying down disorganised type III collagen and a remodelling stage of months to over a year replacing it with aligned type I, and it runs under a specialist, in a boot or a sling and then a programme, with the decision between surgical repair and non-operative functional rehabilitation made on the tendon and the person, the Achilles literature finding the two routes produce similar function with different risks. In that setting no collagen trial has been run: no randomised trial has given collagen peptides to people with a ruptured or repaired tendon and measured healing, strength, re-rupture or return, so the honest answer for repair one is that collagen is untested, not disproved and not supported, and the healing is the clinician's, with nutrition holding the floor beneath it, protein at 1.6 to 2.2 grams per kilo, adequate energy, no smoking, and a reader who wants to add the pre-loading protocol to the rehabilitation sessions doing so as a mechanism-based adjunct discussed with the physiotherapist and not as a treatment of the rupture. The marketing that sells collagen for tendon repair with a picture of a torn tendon is selling to repair one with evidence from repair two, and the split is the whole of the honesty.

Repair two: the chronically painful tendon, where collagen has a marker trial and one small outcome trial

Repair two is the remodelling of a chronically painful tendon, tendinopathy, the lifter's usual tendon problem, which is not a tendon moving through the stages but healing that stalled, the biopsies showing disorganised collagen, high cellularity, water, new vessels and nerves, a stage-two picture that never progressed, restarted by progressive loading that gives the fibroblasts a tension to align to. Here collagen has two pieces of evidence and the honest page gives both their size. The first is the marker trial: a small crossover study gave around fifteen grams of gelatin with roughly 50mg of vitamin C an hour before six minutes of skipping and roughly doubled a blood marker of collagen synthesis against placebo, with engineered ligaments grown in the participants' serum coming out stiffer and richer in collagen, the basis of the pre-loading protocol, a marker and not an outcome, in a handful of people. The second is the one clinical trial, and it deserves its exact description because it is the only collagen tendon trial with a patient outcome: around twenty people with chronic Achilles tendinopathy were randomised to 2.5 grams a day of specific collagen peptides or placebo, both groups doing a six-month calf-strengthening programme, and the collagen group improved more on a validated Achilles function and pain score and returned to running sooner than the placebo group, a result that was statistically significant, small in participants, six months in duration, funded by the peptide's manufacturer and, crucially, obtained alongside the loading programme that is the established treatment, so that the trial shows collagen may add something to loading and cannot show collagen doing anything without it. That is the whole of repair two's evidence: a mechanism with a marker behind it and one small outcome trial beside exercise, enough for a physiotherapist to call the protocol a reasonable adjunct with flat expectations and nowhere near enough for a claim, of which collagen holds none. Two notes finish the split. The dose in the clinical trial, 2.5 grams, was a fraction of the protocol's fifteen, and the two doses have not been compared, so a reader may run either with the same honest uncertainty. And marine or bovine does not change any of it, the trials having used mammalian peptides and the mechanism being shared, so the animal is chosen by allergy, diet and the tub's file. The worked example is the adjunct on its true terms: two capsules, 1200mg hydrolysed type 1 marine collagen with 12mg vitamin C plus zinc, 120 for £16.99 at 28p a day, lab tested and UK made, a dose near the clinical trial's 2.5 grams and well below the protocol's fifteen, taken for vitamin C's collagen formation sentence beside the programme, while the protocol lifter buys the fifteen grams as powder for the hour before the session. Does collagen help tendon repair: for a rupture, untested and the specialist's work; for a chronically painful tendon, an adjunct with a marker and one small trial, beside the loading that does the repairing.

What to check on the label