H37 herbal booster

How imortant is the herbal booster? Is it considered optional, or is it just as important as steps 1 and 2? I notice the herbal booster is the only one that is not available in the higher quantity/discount.

I've been taking HF37 since March only steps One and Two...as directed and I promise I could see results in nails in two weeks, and improved hair, growth and texture in about three weeks. I'm still taking it...I too was curious about the booster, actually added a bottle of it to my last order, have been taking it for about a week and a half. Have no idea how or if it's contributing. But I couldn't be happier with the results I've had overall with HF37