When mice were given a daily shot of a peptide called MOTS-c, their bodies became better at using sugar for energy and responding to insulin, especially in their muscles.

After a week of MOTS-c injections, mice could process insulin better, needing 30% more glucose to keep blood sugar stable during a test.

When mice ate a high-fat diet, daily MOTS-c injections helped them stay lighter than untreated mice, even though they ate the same amount of food.

Diabetic rats given MOTS-c had lower blood sugar levels after fasting, showing better control of glucose.

Obese mice given MOTS-c injections for three days had lower blood sugar levels than mice that didn't receive the treatment.

MOTS-c made muscle cells produce more GLUT4 (a sugar transporter) and turned on AMPK (an energy sensor), two key players in how muscles use sugar.