Xanthan Gum
What-it-does:
viscosity controlling,
surfactant/cleansing,
emulsion stabilising
It's one of the most commonly used thickeners. If the product is too runny, a little of xanthan gum will help make it more gel-like. The slight problem with it though is that too much xanthan gum tends to make the product sticky.
BTW, it’s natural stuff produced from some sugars called glucose and sucrose. It’s approved by Ecocert and also used in foods (E415).