Vitex

Vitex was a health drink developed by Pete Tyler and his counterpart in "Pete's World".

History
In 1987, Pete kept bottles of the juice in his flat in the Powell Estate, which Rose pointed out to the Ninth Doctor when they visited the flat during the alternate timeline created when Rose saved her father from being hit by a car. Jackie described it as tonic water. (TV: Father's Day)

Though nothing came from it in the Doctor's universe, in a parallel world it became extremely successful and made Pete a millionaire. The Vitex brand was bought by Cybus Industries at some point in 2005. Their slogan was "Trust me on this." After the President of Great Britain commented that it tasted like pop, Pete told him it actually was pop. (TV: Rise of the Cyberman) An advert for Vitex was present on the Cybus Industries website. (WC: Vitex)

Information from invalid sources
According to an article on the Cybus Industries website, Cybus Fitness and Vitex could give you the "perfect body". (NOTVALID: About Cybus)

Each flavour of Vitex was advertised to have various beneficial properties to the human body. (NOTVALID: The Time Traveller's Almanac)

The flavours and properties were:
 * Cherry - reduces Wrinkles.
 * Pineapple - probiotic; prevents Hair Loss.
 * Sunrise (berries) - antioxidants; lengthens Life.
 * Violet (blackcurrant) - melts fat; vitamin C Boost.
 * Water lite - plain water with additives.