Not illegal. It is not illegal to buy counterfeit brand sanitary napkins in Pinduoduo, and it is illegal to sell counterfeit brand sanitary napkins. Pinduoduo is the mainstream e-commerce application product of domestic mobile Internet. The third-party social e-commerce platform focusing on C2M group purchase was established in September 2065438+2005. By initiating group shopping with friends, family and neighbors, users can buy high-quality goods at lower prices.