Growthick Fattening Shampoo. Growthick Hair Fattening Shampoo is a special blend of natural ingredients that gently washes away buildup and neutralizes impurities to improve the overall health of the hair. This unique formula can be used daily to penetrate deep within the hair shaft producing a lush, full mane of hair. Growthick Shampoo is a specail blend of natural Thickeners that expand the hair shaft to produce fave, healthy and thick hair GROWTHICK. Directions: Wet Hair thoroughly. Apply a generous amount of Growhick hair fattening shampoo and massage into scalp. RInce and Repeat. Use Groganics Featherilte Volumizing Conditioner.