I've been pre-loading both.. I also did some research about Milk thistle and the benefits it has on patients who take with harsh medications, Milk thistle helps restore the liver and assists with toxic break down. THE BIG THING TO KNOW IS - These patients are seeing results with 500mg-800mg of STANDARDIZED 80% Milk thistle (Silybum extract)"Silymarin"..... Now if your going to buy a Milk thistle at Wal-mart make sure to look on the back of bottle to see if it says "Standardized milk thistle 80% Silymarin".. This means that it has higher amount of ( Silybum Extract) Which the actual Ingredient that helps protect & restore the liver. If it says "Milk thistle (seed)" on the ingredients that means this product has about 5-7% of Silymarin in it..
As for Hawthorne, I know that it can be extracted and standardized as well. Im not sure of any effective dosing procedures for Hawthorne. The Effective chemical in Hawthorn is Vitexin. "Typical suggested dose for standardized extracts ( approx. 2% of vitexin-rhamnozide and/or 18% of total proanthocyanidins) is in the range of 250 - 600 mg daily."
Cycle assist can be more expensive than just milk thistle or hawthorn, but both are standardized in Cycle assist.
PLUS, Cycle assist has N-Acetyl-L-Cysteine, 'known as "NAC" which provides powerful immune support and also packs a powerful anti-toxin potential' Also, 'NAC has been shown to play a protective role against a variety of toxic hazards such as cigarette smoke, auto exhaust, certain herbicides, and overdoses of acetaminophen. It can also play a beneficial role in prostate and respiratory conditions' Which I think pre-loading is a great way to prep your immune system.