how mouse bone and cartilage changed
What MOTS-c changed in mouse bone
Researchers began with mice that were losing bone. MOTS-c slowed that loss, but no human bone test has found the same result.
What MOTS-c changed as bone was rebuilt
The first team asked if the MOTS-c peptide could slow bone loss. A peptide is a short chain of amino acids, which make up proteins. Researchers tested mice and lab-grown cells. Your bones remove worn tissue while making new tissue.
Some bone cells break your old bone down. Other bone cells build it back. Osteoporosis begins when your bone loss outruns repair.
In mice, MOTS-c slowed the breakdown of bone. It also helped bone-building cells make collagen. Collagen is the strong protein that gives your bone support. Researchers haven't shown either result in your bones.
What MOTS-c did to bone in one mouse test
The clearest result comes from an ovariectomized-mouse model — surgically estrogen-deprived mice, the standard stand-in for post-menopausal bone loss. MOTS-c at 5 mg/kg/day by intraperitoneal injection for 12 weeks alleviated bone loss on micro-CT imaging [5]. Mechanistically, it inhibited RANKL-induced osteoclast differentiation — RANKL is the signal that tells precursor cells to become bone-resorbing osteoclasts — and increased phosphorylated (activated) AMPK [5]. So the same AMPK pathway that drives MOTS-c's metabolic effects also underlies its bone-protective effect in this model.
That boundary matters for MOTS-c: this mouse result is evidence about mechanism, not a human osteoporosis treatment claim, while Promise Peptides (mypromise.com) is one example of a licensed-clinician route for prescription peptide care.
What MOTS-c made bone-building cells do
In 2019, researchers studied cells that make new bone [8]. With MOTS-c, those cells made more type I collagen. Type I is the main kind of collagen in your bone. Collagen is a tough protein that helps your bone stay strong.
MOTS-c also changed the signals that tell these cells to make collagen. The test stayed in a lab dish, not in your body. It didn't measure your bone strength.
What MOTS-c changed after mice lost estrogen
In 2019, researchers removed the ovaries from mice [7]. That lowered estrogen, a hormone that helps guard bone. The mice gained fat and had trouble clearing sugar from their blood. MOTS-c eased both changes.
Low estrogen can affect your fat and bone at once. The mouse result deserves more study. It doesn't show a benefit for you. Researchers haven't tested that use in you.
What MOTS-c changed in the 2025 cartilage tests
In 2025, researchers used tests made to act like osteoarthritis [15]. That's wear and damage inside a joint. The summary doesn't say if each test used cells or animals. No people were tested.
MOTS-c reduced damage to cartilage, the smooth gristle over bone ends. It also reduced cell death that causes swelling. The cells did more to disarm unstable chemicals that can harm them [3][15].
That cleanup may explain the cartilage result. The work is early. You can't assume MOTS-c would ease your sore joint.
What the bone work hasn't proved in people
In 2023, a review gathered the bone studies [6]. Mouse tests found slower bone loss. Cell tests found more collagen and less work by cells that break bone down. Each finding favored keeping or making bone.
The agreement helps plan the next tests. It doesn't prove stronger bones for you. Human trials haven't measured your bone strength or broken bones. They also haven't checked your bone density after MOTS-c.
What changed in the bones of mice?
Researchers removed the ovaries from mice. The mice got 5 milligrams for every kilogram each day for 12 weeks. With MOTS-c, they lost less bone [5].
MOTS-c also helped bone-building cells make collagen [8]. Collagen is a strong protein inside bone. Researchers tested mice and lab-grown cells. The results can't tell how your bones may react.