No harm. Loofah insoles utilize the important natural ingredients contained in loofah and have significant effects on corns and heel pain. It is comfortable to wear, soft, dirt-resistant and wear-resistant, and can easily eliminate fatigue. Luffa insole products overcome the shortcomings of cloth insoles that are prone to mildew, leather insoles that are stiff, deformed, and smelly, and plastic insoles that are slippery and smelly. When wearing, the rough side should be facing downwards, and the smooth loofah should be directly close to the soles of the feet. It is normal for the socks to stick to the socks for the first three days after wearing them, and they will disappear naturally after a week. After a destructive test by the factory, the insole was worn for a week and walked more than 10 kilometers a week without changing socks or washing feet, and no foot odor or sweat occurred. It is especially suitable for women because the insole absorbs sweat in summer. It has a cooling effect and has the functions of keeping warm, massaging and health-care in winter.