He stops at the bottom of the stairs.

Not for long. A second, maybe two. He looks up, then goes. Two years ago he’d have been at the top already.

You didn’t notice the stairs getting steeper. Nothing about them changed. What you noticed was him stopping at the bottom.

And once you saw that one, the rest showed up. The slow-motion sit, lowering down in stages like he’s checking the floor will hold. A back paw sliding out on the kitchen tile and having to be re-planted. The couch — front paws up, then a pause, then a look at you.

Then the part almost nobody says out loud. You’ve started helping him up. A hand under the back end in the morning. A lift into the car. You can’t remember the first time, because it arrived one favour at a time.

And here’s what makes it strange. His spirit hasn’t changed at all. He still plays. He just can’t do the stairs.

That gap — spirit fine, back half not — is the part worth attention. If age were simply wearing him down it would show everywhere at once. It doesn’t. Shoulders solid, chest strong, paws still up on you like always.

It’s the back half you see first. And the reason isn’t in the joint.

• You put a hand under his back end to help him up, and you do it most days now
• You watch him pause at the bottom of the stairs before he commits
• You’ve added rugs or runners to the rooms with hard floors
• You lift him into the car instead of opening the door and waiting
• You notice he lowers into a sit in stages instead of one movement
• You’ve caught yourself planning the walk around what he can still manage
• You already bought a joint chew or a glucosamine powder, and nothing changed

If three or more of those landed, you’re not imagining a pattern. There is one, and it has an order.

The back legs usually aren’t the first thing to go. They’re the first thing you see go.

What changes earlier is reserve — the gap between what a movement costs and what the body can put behind it. While that gap is wide, everything he does looks free. As it narrows, nothing breaks; movements just stop being free. And the first place a narrow gap shows is the place with the biggest bill.

That’s the back half. The rear legs carry the largest muscles in a dog’s body and do the pushing, and they sit at the end of the longest wiring he has. Biggest cost, longest run. So that’s where it shows first.

And it isn’t only the joint. In dogs, lean mass peaks in middle age and declines from there [1]. Muscle is what moves a joint.

One caveat, and it matters more than anything else here. Not every change in an older dog’s back legs is about reserve. Some are medical conditions that look almost identical from the doorway and need a vet, not a supplement. If it came on fast, or one side is clearly worse, get him seen first.

Most people reading this have already spent money here. A bag of chews. A tub of powder. Maybe three brands across two years, each one bought with real hope.

Then nothing changed, and somewhere in the back of your mind you filed it under your own fault. You didn’t give it long enough. You should have read more labels.

Almost none of that is true, and the two real explanations have nothing to do with your judgement.

First: the joint was never the whole problem. A joint doesn’t move itself. Muscle moves it — and cushioning a joint does nothing for muscle that’s short on what it runs on.

Second: the shortage sits a level below that. Muscle cells are dense with mitochondria, the small power plants that turn food into usable energy. They spend a helper molecule called NAD+ to do it, and with age the mitochondria doing that spending get measurably less efficient [2].

There’s a second half to that, worth stating carefully. In studies on aging mice, an enzyme called CD38 climbs with age and drives NAD+ down [3]. That part hasn’t been studied in dogs yet — read it as the direction the research points, not a fact about your dog.

Less made. More spent. A body with less to spend doesn’t fail all at once; it runs a narrower reserve. Which brings you back to the biggest muscles doing the heaviest job, and the stairs he now stops at.

Pawprint Protocol was built by owners who had already walked the joint aisle and wanted to know what sat underneath it. Working with veterinary advisors, they built a daily liquid around one job: give muscle cells the building block they use to make NAD+, in a form that actually arrives.

The lead active is NMN — the direct building block for NAD+, and the only active here with published dog research attached. Here is exactly what that research is:

One study measured NAD+ inside dog muscle, and topping it up changed measurable things in that tissue [4]. But those dogs were bred as a research model of a genetic muscle condition, not healthy older dogs, and the compound wasn’t this one. It proves nothing about this bottle — what it shows is that NAD+ in dog muscle can move.

Oral NMN also went through a safety study in beagles that reported a safe dose range [5]. That study was about safety: the NAD+ readings in the same paper came from mice, not the dogs. Nobody should tell you NMN raises NAD+ in a dog — it hasn’t been shown yet.

That’s mechanism and category evidence, not proof about your dog.

Then delivery. This is a liposomal liquid, not a pill or a chew — each active wrapped in a protective layer so more of what’s in the dropper reaches the cell. Built to be absorbed, not just swallowed. A few drops on whatever he already eats. Individual results may vary.

The senior shelf is a wall of the same promise: cushion the joint, ease the stiffness. If that promise had worked for your dog, you wouldn’t have read this far.

Pawprint Protocol isn’t on that shelf, and it’s worth being blunt about why. No glucosamine. No chondroitin, no MSM, no collagen. It is not a joint-structure formula.

It works one level below — at the muscle cell that powers every push those back legs make. A few drops on his food, once a day.

Four actives, each with a job:

• NMN: The direct building block cells use to make NAD+, the helper molecule the cell’s power plants spend. The lead active, and the only one with published dog research.
• NAD+: On the same pathway, supporting the cellular energy those rear muscles draw on all day.
• Resveratrol: A plant compound studied alongside NAD+ in the cell’s energy and repair signalling.
• CoQ10: Sits inside the mitochondria, where energy actually gets made.

All four in a liposomal liquid, because an ingredient that never gets absorbed is a line on a label, not a dose.

✔ Supports normal mobility and steadiness
✔ Supports the cellular energy muscle and nerve tissue run on
✔ Built to be absorbed, not just swallowed
✔ Works alongside any food — kibble, raw, fresh or home-cooked

Made for dogs 7 and up. Individual results may vary.

You don’t have to wait three months to see anything. Most owners tell us the first changes arrive in days to weeks, and they rarely look dramatic — they look like one less thing you have to do for him. Here’s the pattern owners describe most often. Individual results may vary.

Small enough to miss if you’re watching the stairs. He gets up off the floor on the first attempt instead of the second. The slow-motion sit speeds up a beat. What owners mention most from this stretch isn’t a moment — it’s catching their own hand reaching to help him stand, and finding he’s already standing.

This is usually where the pause at the bottom shortens, then quietly stops happening. The couch comes back — up on the first try instead of paws-up-and-wait. Walks stretch out because he didn’t turn for home, not because you talked him into it.

Owners bring up hardwood and tile here. Less scrabbling. Fewer moments where a back paw slides out and has to be re-planted. He crosses the kitchen instead of tracking the runner you put down for him. Good days start being most days.

For most families this is the one that actually registers: they haven’t put a hand under his back end in weeks, and they can’t say which day that stopped.

Three months in, the job changes from noticing to holding. Lean mass doesn’t wait and NAD+ naturally declines with age, so the dogs that hold their ground are the ones who stay on it.

And plainly: the more reserve there is when you start, the more there is to work with. Individual results may vary.

Weak back legs aren’t where this started. They’re the part that finally became visible.

Everything before it — the shorter walk, the slower rise, the careful line across the tile — was the same narrowing reserve, showing up quietly. The muscle didn’t quit on him. It ran short of what it needs to do the most expensive job in his body.

That part is supportable. And it starts with a few drops on dinner tonight.

Reviews are unedited excerpts from verified Trustpilot reviews of Pawprint Lab. Individual results may vary.

[1] McGrath AP et al. Retrospective analysis of dual-energy x-ray absorptiometry data demonstrates body composition changes with age in dogs and cats. Am J Vet Res, 2024. PMID 39393400. Non-clinical retrospective in colony-housed dogs; it sets no rate for any individual dog.

[2] Chistiakov DA et al. Mitochondrial aging and age-related dysfunction of mitochondria. Biomed Res Int, 2014. PMID 24818134. Review.

[3] Camacho-Pereira J et al. CD38 Dictates Age-Related NAD Decline and Mitochondrial Dysfunction through an SIRT3-Dependent Mechanism. Cell Metab, 2016. PMID 27304511. Mouse study.

[4] Cardoso D et al. Replenishing NAD+ content reduces aspects of striated muscle disease in a dog model of Duchenne muscular dystrophy. Skelet Muscle, 2023. PMID 38044436. Non-clinical; dogs bred as a disease model, not healthy aging dogs, and a different compound — not this product.

[5] You Y et al. Subacute Toxicity Study of Nicotinamide Mononucleotide via Oral Administration. Front Pharmacol, 2020. PMID 33384603. Safety study in beagles; NAD+ was measured in mice, not dogs.