The short answer
Tendons and ligaments heal slowly and the repair is weaker than the original. The best results come from an early scan, patient rehab and rescans before each step up in work.
Signs to look for
- Heat on the back of the lower leg
- Swelling, or a curved “bowed” outline
- Lameness, sometimes only slight
- Pain when the area is pressed
Treatment options
Rehab, month by month
- Weeks 1 to 2Box rest, cold therapy, first scan
- Months 1 to 3Hand walking that builds up, rescan
- Months 3 to 6Walking under saddle, then short trots
- Months 6 to 12Back to work slowly, scan before each step
A typical plan. Your vet sets the pace from the scan results.
Gear that helps the rehab
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BPC-157 and TB-500 for tendon and ligament injuries: what is known
Peptides are sold widely for horse tendons. Here is what is actually known. Neither is FDA-approved for animals, and competition rules apply.
What is the best peptide for a horse's tendon injury?
No peptide has been shown to help a horse's tendon or suspensory injury, so there is no best one. BPC-157 and TB-500 are not officially tested in horses, and TB-500 is banned by the FEI. What vets rely on is an early scan, controlled rehab and rescans before each step up in work.
Found heat or swelling on a leg? See a vet first
Stop riding and call your vet. A leg that looks better by the weekend can still have a damaged tendon, and some injuries show little or no lameness. Ask your vet whether to cold hose and bandage while you wait. A horse that will not put weight on the leg needs a vet visit now.
Our tendon and ligament page sets out the signs and a typical rehab plan. This guide covers the question owners ask next: should a peptide be part of it?
Bowed tendon or suspensory injury: what is the difference?
Both are soft tissue injuries in the lower leg, but they sit in different places and behave differently. Tendons have a limited blood supply, so healing is slow, and the Merck Veterinary Manual says the repair tissue is usually weaker than the original. That is why rushing back to work causes so much trouble.
| Injury | Where | What you may see |
|---|---|---|
| Bowed tendon (superficial flexor) | Back of the cannon | Heat, swelling and a curved outline |
| High suspensory | Top of the cannon, just below the knee or hock | Sudden lameness that improves in days, worse on soft ground and on a circle |
| Suspensory body | Middle of the cannon | Enlargement, heat, swelling and pain when pressed |
| Suspensory branch | Just above the fetlock | Heat and swelling, sometimes with no lameness at all |
How do vets diagnose and rehab these injuries?
An ultrasound scan is the core test, and it sets the pace for everything that follows. Findings need careful reading, and high suspensory injuries often need nerve blocks first to find the sore spot. MRI can show subtle changes a scan may miss, and a bone scan can pick up injury where the ligament attaches.
Rehab means rest at first, then controlled exercise that builds up in steps, with a rescan before each step. Merck gives about 3 to 6 months of rest and controlled exercise for a new high suspensory injury in a front leg, and says coming back too soon often brings recurrence or lasting lameness. Branch injuries can take 6 months or more to improve. Tendon injuries often take 8 to 12 months.
The outlook depends on the injury. Merck reports about 90% return to function for new front-leg high suspensory injuries with proper rehab, and only a guarded to fair outlook for hind legs. Your vet can give you a view for your own horse from the scan.
Which biologic treatments do vets use?
The main ones are platelet-rich plasma (PRP) and stem cells, usually made from your horse's own blood or cells and injected into the injury under scan guidance. Vets also use shockwave, often for ligaments. Merck says these newer options, combined with specific rehab programs, have improved the outlook for tendon and ligament injuries.
The evidence is real but mixed, so ask what it means for your horse. In one report, 13 competition horses with stubborn injuries were given PRP and bone marrow cells, and 84.6% returned to competition, but the abstract describes no untreated comparison group. In a blinded, randomized study of nine horses with surgically made tendon lesions, a single injection of fat-derived stem cells did no better than serum alone over 22 weeks.
These treatments differ from peptides in one important way. They have been studied in horses, and they are given by a vet who can see the injury on the screen.
What is known about peptides for horse tendons?
Almost nothing in horses. BPC-157 and TB-500 are the two owners ask about, because lab work on tissue repair gets repeated on sales pages. Neither is officially tested in horses, and neither is FDA-approved for animals. No clinical trial of either in horses appears in PubMed. BPC-157 returns no PubMed results at all for horses. The TB-500 papers in horses that matter here are about catching it in drug tests.
So nobody can say whether either one changes tendon healing, what a safe amount would be, or what it does to the quality of the repair. A horse that comes sound after a peptide proves little, because rest and time were at work too. Infection is a real risk as well. An infected tendon sheath needs antibiotics, flushing and drainage, so nobody should inject around one at the yard.
For a competition horse the answer is simple: do not use any of them. The FEI bans TB-500, and BPC-157 is not cleared either. Our guide to BPC-157 vs TB-500 compares them side by side.
What to ask your vet about a tendon injury
Good questions keep rehab on track and stop money going on the wrong thing. If you are thinking about any product, tell your vet what it is before you give it.
- Which structure is hurt, and how bad does it look on the scan?
- When is the next rescan, and what result lets us step up?
- Would PRP, stem cells or shockwave suit this injury, and what does the evidence show?
- What is the realistic outlook for the work I want this horse to do?
- Does any treatment we are planning affect competition rules?
Questions horse owners ask
How long does a tendon injury take to heal?
Often 8 to 12 months, depending on the tendon and how bad the damage is. Rescans tell your vet when it is safe to add more work. Rushing is the most common reason for a second injury.
Will my horse compete again?
Many do, often at a level close to before, but re-injury is common. Your vet can give you odds for your horse based on the scan and the type of work you plan.
Can I use TB-500 on a competition horse?
No. The 2026 FEI list bans synthetic thymosin fragments, and labs can test for TB-500. Check the rules of your own federation or racing body too before giving any product.
Does horse insurance cover tendon injuries?
Many policies with vet fee cover do, if the injury is new and not excluded. Check the limit per condition, because rehab and repeat scans add up.
Which is better for a bowed tendon, BPC-157 or TB-500?
Neither has been officially tested in horses, so there is no honest way to rank them. No clinical trial of either in horses has been published. What vets rely on for bowed tendons is an early scan, controlled rehab and rescans.
Will a peptide shorten my horse's rehab?
Nobody can say, because no trial has measured it. Rushing is the known danger. Merck says coming back too soon after a high suspensory injury often brings recurrence or lasting lameness, so let the rescans set the pace.
How long does a suspensory injury take to recover?
It depends on where it is. Merck gives about 3 to 6 months of rest and controlled exercise for a new high suspensory injury in a front leg, and 6 months or more for signs to improve in branch injuries. Your vet will judge your horse from the scans.
Is PRP a peptide treatment?
No. PRP is made from your horse's own blood and injected by a vet, usually under scan guidance. It has been studied in horses, though results vary. A vial of lab-made BPC-157 or TB-500 has not been officially tested in horses.
Can a competition horse have TB-500 for a tendon?
No. The 2026 FEI list bans synthetic thymosin fragments, which covers TB-500, and labs can detect it in horse urine and plasma. Check your national federation and any racing rules too.
Sources
- University of Minnesota Extension, Bowed tendons in horses. Open
- Merck Veterinary Manual, Tendon Disorders in Animals. Full review Oct 2025. Open
- Merck Veterinary Manual, Suspensory Desmitis in Horses. Full review Oct 2025. Open
- Torricelli P et al. Regenerative medicine for the treatment of musculoskeletal overuse injuries in competition horses. Int Orthop, 2011. Open
- Geburek F et al. Effect of single intralesional treatment of surgically induced equine superficial digital flexor tendon core lesions with adipose-derived mesenchymal stromal cells. Stem Cell Res Ther, 2017. Open
- PubMed, BPC-157 in horses, all study types: no results, checked 6 Nov 2026. Open
- PubMed, TB-500 and thymosin beta-4 in horses, clinical trials only: no results, checked 6 Nov 2026. Open
- Ho ENM et al. Doping control analysis of TB-500 in equine urine and plasma. J Chromatogr A, 2012. Open
- FEI, 2026 Equine Prohibited Substances List. Open