A connector according to the invention includes a first connection region for connecting a first container, a piercing element and a break-open element, wherein the piercing element has a first end section and a second end section and a channel, running from the first end section to the second end section, for transporting a medicinal active substance, wherein the first end section is formed for piercing a membrane of the first container connected in the first connection region, and, at the second end section, the break-open element is attached such that it can be broken open and/or broken off, wherein, in the attached state, the break-open element seals the channel of the piercing element in liquid tight fashion.
