As of April 2014, Flex shampoo is still produced by Revlon, although many varieties of Flex have been discontinued. Few stores carry the brand; however, it is available online at Amazon.com.
Flex was once a popular line of shampoos and conditioners back in the 1970s and 1980s because it had many of the same cleansing properties of salon-style hair products, but with a low price. In the 1980s, the makers of Flex created new packaging for the product with a high-end look; the new packaging apparently led people to assume that the price of the shampoo had risen significantly. As a result, Flex gradually became difficult for shoppers to find.