What is Bladderwrack Extract? Bladderwrack extract is taken from the bladderwrack algae, also known as Fucus vesiculosus, rockweed, black tang, bladder fucus, cutweed or Dyer’s fucus. This perennial green-brown seaweed grows along the Eastern and Western North American coastlines and European coastlines north of the Mediterranean (x). The seaweed has frondsContinue Reading