1. I've been using this Fast Shampoo for 4 months now, and in just 2 months, I've transitioned from a medium-length cut to long hair. The exact growth measurements were: 1.5 cm in the first month, 2.2 cm in the second month, and 2.0 cm in the third month. I bought this shampoo solely because I wanted my hair to grow faster, and it really does work! Some people say that 1.3-1.5 cm of growth per month is not much, but normal hair growth is actually 0.8-1.2 cm per month. So the growth I'm experiencing is quite effective. Suddenly growing 3-5 cm per month would be like a magic potion, not a regular shampoo, right? (Of course, some people with hair that's very responsive to shampoos can see 3 cm of growth, but that's a special case.) I usually have very slow-growing hair, around 0.7-0.8 cm per month, so the growth I'm seeing makes this an essential product for me. I plan to keep using it until my hair reaches waist-length, which should take 2-3 years, but at this rate, it might only take 1-1.5 years. 2. The ingredients are also quite good. I wasn't specifically looking for a shampoo with great ingredients, but it's still better than those 'hair-thinning' shampoos that make your hair appear to grow faster.

1. It's way too expensive, the price is just insane. 2. It doesn't really feel like I've used a shampoo. The cleansing power and lather are fine, and there's no residue, but it just doesn't feel like I've shampooed my hair. 3. I'll reiterate, the price is just crazy - it's about 5 times more expensive than other shampoos. 4. I have extremely damaged hair (5 bleachings and toning), so I absolutely need a treatment or hair mask. But I'm not sure how it would work for people with normal hair, since I've never had that.

I do a pre-wash with a clarifying shampoo, then apply this product all over and let it sit for about 3 minutes before rinsing. When I used to use the Fast Shampoo without the waiting time, the results were noticeably better when I started letting it sit for a few minutes.

I really wanted my hair to grow faster because I have a terrible haircut, so I was glad when my hair grew quickly.

It was really slippery and easy to drop, so that was disappointing.