5 reasons why climbers are using this to stop re-tweaking the same pulley without cutting back on their sessions

The finger injury that “resets your progress” is the #1 reason climbers quit, and it drags on for one physical reason: pulleys and flexor tendons barely get blood supply, so they’re slow to rebuild and quick to run short on raw material.

Crux floods your system daily with 15g of hydrolyzed collagen peptides — the exact glycine and proline your finger tendons and pulleys are built from — so the tissue crimping tears down has a surplus to rebuild with. Not a stimulant. Not a painkiller. The literal building block.

Most climbers notice the inflamed-finger ache settle in the first week; the rebuild under load shows up over 4–6 weeks of daily use. It’s not a cure — it’s giving slow-healing tissue the one thing rest can’t: material.

In this article:

Here’s what almost nobody realizes: the collagen tub in your kitchen was built for skin, hair, and nails. It’s a beauty product that happens to contain the same protein your tendons are made of — under-dosed and formulated for the mirror, not the wall.

Crux is the opposite. It was engineered backwards from one question: what actually breaks when you climb? The answer is your fingers — the A2 pulley, the flexor tendons that hold your entire bodyweight on a half-pad crimp. So Crux is dosed for that tissue and only that tissue:

• 15g collagen peptides — a real tendon dose, not a beauty sprinkle
• 50mg vitamin C — the cofactor your body physically cannot build collagen without
• 150mg Boswellia — calms inflamed fingers without the ibuprofen problem (more on that below)

That’s the difference in one line: this was made for the hands you climb with, not the face you post with.

Half of experienced climbers already half-know this science — they just haven’t had it in one product.

There’s a well-known window (climbers call it the “Keith Baar protocol”) where taking collagen peptides plus vitamin C before you load the tendon puts the raw material in circulation exactly when the tissue is being stressed and signaled to rebuild. It’s why serious hangboarders sip gelatin before sessions.

Crux isn’t a guess at those numbers — the 15g collagen + 50mg vitamin C dose is built around that protocol, so on climbing days you can take it 30–60 minutes before you load your fingers and hit the window without measuring scoops of drink gelatin. You were half-doing this already. This just productizes it.

The single biggest lever on a page like this is authority — showing the mechanism, not just claiming the benefit. So here’s exactly what’s inside and what each ingredient is there to do:

Four ingredients, four jobs, in order: collagen supplies it, vitamin C builds it, copper strengthens it, Boswellia protects it. No proprietary-blend fog, no beauty filler — just the tissue your sport destroys, addressed step by step.

Two problems every climber over ~30 knows intimately, and Crux addresses both:

1. The fingers that never feel healthy. “My fingers feel tweaky after every boulder session… no matter how much rest.” Rest was the only tool you were handed — and for a lot of climbers it’s stopped working. Daily collagen keeps raw material available continuously, so damage stops stacking session over session, and Boswellia takes the morning stiffness down while it does.

2. The painkiller that may be working against you. This is the one most climbers get wrong. The ibuprofen you take for a tweaked finger can blunt the exact inflammatory signaling the tendon needs for early repair. You feel better and heal slower at the same time. Boswellia calms the ache through a different pathway — so you get relief without paying for it in slower healing.

And the quiet fear underneath all of it — arthritis knuckles at 50 — is why every Crux comes with the nightly joint capsule included: it defends the joint cartilage under the tendon through a separate mechanism. Tendons by day, joints by night.

The tendon rebuilds on a timeline of weeks, so Crux comes with a 90-day money-back guarantee — long enough to actually feel the difference. If your hands don’t feel more supported through your sessions, you email us and get refunded, even if the pouch is empty.

You won’t be the first to try it. Crux is rated 4.8/5 across 2,000+ climbers — boulderers, sport climbers, and the over-35 crowd whose “hands stopped feeling 50.” One line that keeps coming up: “finally something made for fingers, not faces.”

• 15g of real tendon-dose collagen — the material your pulleys are made of
• The vitamin C cofactor that actually lets your body build it
• Boswellia for relief that doesn’t stall the repair
• 90-day money-back guarantee — even if the pouch is empty
• Free US shipping