We all want to live longer and stay sharp, but what’s the price, exactly? It can’t promise results, but one buzzy supplement does claim some pretty big benefits. A single pack usually costs a hefty $280 on Amazon , but for October Prime Day , it’s 25% off. Fatty15 developed its award-winning fatty acid supplement after a decade-long collaboration with scientists and the U.S. Navy. The fruits of their labor: a formula that is said to strengthen cells by 80%, improve mitochondrial function by 45%