A remarkably brief exposure to a multidrug cocktail enabled frogs to re-grow largely functional limbs after amputation, investigators from Tufts University reported in the January 26, 2022, issue of Science Advances. Twenty-four hours of exposure to five factors – brain-derived neurotrophic factor (BDNF), growth hormone (GH), 1,4-dihydrophenonthrolin-4-one-3carboxylic acid (1,4-DPCA), resolvin D5 (RD5) and retinoic acid (RA) – set off regeneration processes that continued for 18 months.